ALBERT

Description: With the ongoing deployment of Global Navigation Satellite Systems (GNSS) ground stations and the modernization of satellite signal systems, the utilization of various augmentation technologies enables the realization of Precise Point Positioning (PPP) in real-time. Augmentation technology, which introduces precise atmospheric and signal-related delays, has become an essential component of high-precision real-time services and is attracting growing interest in scientific research, disaster monitoring, autopilot, etc. Previous studies have dedicated significant efforts to enhance the generation and dissemination of augmentation information on the service side and improve real-time positioning algorithms on the user side. The real-time atmosphere augmentation information with sufficient accuracy and proper constraint, and reliable Ambiguity Resolution (AR) for this purpose is the main focus of current GNSS research. However, these efforts have primarily been concentrated on small or medium-sized regions with the capability for transmitting massive data volumes. Alternatively, they have focused on larger areas, but with slow convergence due to the imprecise nature of atmosphere information. To address the challenge posed by the trade-offs among service area size, correction volume, and the precision of represented correction, a new augmentation strategy is proposed. This approach integrates the advantages of atmospheric delay fitting models, unmodeled residuals, and uncertainty information to achieve rapid and high-precision positioning, all while reducing data transmission volume for larger areas. It also allows users to implement different positioning modes depending on their communication capacity. Additionally, all deviations among different types of receivers and satellite signals are calibrated in this study for reliable AR can be achieved on all reference stations. The main contribution of this thesis is summarized as follows. With the real-time precise orbit, clock, and Uncalibrated Phase Delay (UPD) products, precise atmospheric delay corrections relying on reliable AR can be derived for large-areas augmentation services. To address the challenge of achieving reliable AR across different receiver types and various satellite signals, this thesis proposes a comprehensive method for calibrating receiver-type-related satellite-specific deviations and analyzes the impact of satellite signal bias corrections in data processing. The primary objective is to enhance the reliability of AR, enabling the utilization of all available signals and receiver types in large-area services. Subsequently, new tropospheric and ionospheric delay fitting models applied for large-area are carried out according to the properties of their propagation paths. In addition, the corresponding atmospheric delay uncertainty for large areas is introduced based on the fitting residuals. Finally, a hierarchical mode is developed for augmentation services, leveraging the advantages of the fitting model and uncertainty grid to reduce data volume and incorporating regional fitting residuals using the interpolation model and ionospheric delay error function, depending on the network capability. Based on hierarchical augmentation, positioning in large areas can not only achieve rapid/instantaneous high-precision convergence but also overcome the conflict among correction volume, represented precision, and coverage size. In order to derive precise atmospheric delay and accelerate positioning, implementing reliable and robust AR across all types of receivers and satellite signals is essential. It also demonstrates and discusses the advantages of calibrating satellite-signal and receiver-type-related satellite-specific deviations in AR solutions. The deviations related to receivers in terms of UPD products are assessed and calibrated, confirming that a 0.03 cycle consistency in wide lane UPD can be achieved. The effectiveness of the proposed approach is demonstrated using GPS satellite signals, which can improve the AR rate by at least 10% and produce more reliable results. In addition, the impact of different signal settings and corrections on orbit, clock, and UPD generation, as well as positioning and pseudo-range signal systematic and stochastic residuals, is analyzed. These processing strategies provide flexible observation selections, allowing the utilization of all available satellite signals and receiver types, thereby enabling reliable AR and a higher fixing rate. As a result, an AR fixing rate exceeding 95% is achievable across all stations in large-area services. For precise atmospheric delay modeling over large areas, new models are proposed, including a tropospheric Zenith Wet Delay (ZWD) model and a satellite-wise ionospheric slant delay fitting model. The tropospheric delay model takes the exponential function of water vapor vertical changes into consideration, addressing model anomalies in areas with large altitude differences. The new ionospheric delay fitting model introduces the trigonometric functions to describe differences in slant path delays between the optimal reference propagation path and others, achieving superior modeling performance in large areas. The precision of the fitting model, utilizing a 200 km station-spacing network, demonstrates tropospheric ZWD and ionospheric slant delays of 1.3 cm and 8.9 cm, respectively, with smaller standard deviations. These new fitting models overcome the challenge of handling massive information for providing station-wise corrections and avoid an increase in the number of coefficients. In addition to the function model, the stochastic model, i.e., uncertainty information, is essential for describing the quality of corrections. The atmospheric delay uncertainty for the large-area fitting model is generated based on the fitting residuals and represented in forms of grid-point. Additionally, regional ionosphere unmodeled residual uncertainty is represented by the form of liner function, which is established by the relationship between distance and interpolation precision through inter-satellite cross-verification among all reference stations. The differences between uncertainty value and real delays are 2.5 cm and 0.5 cm for grid and function forms, respectively. For real-time applications in large areas, the fitting model and grid-based atmosphere uncertainty serve as the essential information, satisfying the requirement of rapid positioning. By further incorporating unmodeled residuals and ionosphere error function, a hierarchical augmentation model is provided. Based on the fitting model established for large areas, unmodeled residuals are further introduced as optional compensation for specific areas, depending on the magnitude of fitting residuals. This approach results in a 97% reduction in tropospheric delay and a 65% reduction in ionospheric delay transmission volume. Furthermore, leveraging the regional high capability of communication, 85.3% of all solutions can achieve instantaneous convergence at the first epoch with the aid of corresponding regional compensation. This thesis proposes a large areas augmentation service to overcome the conflict among correction data volume, represented precision, and coverage size. It demonstrates the benefits of an augmentation mode that integrates regional information into large-area services. Under these conditions, a more reliable and rapid AR solution can be easily achieved based on precise atmospheric delay correction and uncertainty in large areas with fewer data volume requirements. This is beneficial for actual real-time services and applications.

Description: Mit der laufenden Bereitstellung von Bodenstationen für globale Navigationssatellitensysteme (GNSS) und der Modernisierung von Satellitensignal-Systemen ermöglicht die Nutzung verschiedener Augmentationstechnologien die Realisierung der Präzisen Punkt-Positionierung (PPP) in Echtzeit. Augmentationstechnologie, die präzise atmosphärische und signalbezogene Verzögerungen einführt, ist zu einem wesentlichen Bestandteil hochpräziser Echtzeitdienste geworden und findet wachsendes Interesse in wissenschaftlicher Forschung, Katastrophenüberwachung, Autopiloten usw. Frühere Studien haben erhebliche Anstrengungen darauf verwendet, die Erzeugung und Verbreitung von Augmentationsinformationen auf der Dienstseite zu verbessern und Echtzeit-Positionierungsalgorithmen auf der Benutzerseite zu optimieren. Die Echtzeit-Atmosphärenaugmentationsinformationen mit ausreichender Genauigkeit und angemessener Einschränkung sowie zuverlässige Ambiguitätsauflösung (AR) für diesen Zweck stehen im Mittelpunkt der aktuellen GNSS-Forschung. Diese Bemühungen konzentrierten sich jedoch hauptsächlich auf kleine oder mittelgroße Regionen mit der Fähigkeit zur Übertragung großer Datenmengen. Alternativ richteten sie sich auf größere Gebiete, jedoch mit langsamer Konvergenz aufgrund der ungenauen Natur der Atmosphäreninformation. Um der Herausforderung durch die Abwägung zwischen Größe des Dienstleistungsgebiets, Korrekturvolumen und Präzision der dargestellten Korrektur zu begegnen, wird eine neue Augmentationsstrategie vorgeschlagen. Dieser Ansatz integriert die Vorteile atmosphärischer Verzögerungsanpassungsmodelle, nicht modellierter Reste und Unsicherheitsinformationen, um eine schnelle und hochpräzise Positionierung zu erreichen, und das bei gleichzeitiger Reduzierung der Datenübertragungsvolumina für größere Gebiete. Es ermöglicht den Benutzern auch, verschiedene Positionierungsmodi je nach ihrer Kommunikationskapazität zu implementieren. Zusätzlich werden in dieser Studie alle Abweichungen zwischen verschiedenen Typen von Empfängern und Satellitensignalen kalibriert, um eine zuverlässige AR an allen Referenzstationen zu erreichen. Die Hauptbeiträge dieser Arbeit werden wie folgt zusammengefasst. Mit den Echtzeit-Präzbitbahnen, Uhren und Uncalibrated Phase Delay (UPD)-Produkten können präzise atmosphärische Verzögerungskorrekturen für großflächige Augmentationsdienste abgeleitet werden, die auf zuverlässiger AR basieren. Um die Herausforderung zu bewältigen, eine zuverlässige AR über verschiedene Empfängertypen und verschiedene Satellitensignale hinweg zu erreichen, schlägt diese Arbeit eine umfassende Methode zur Kalibrierung von empfängertypbezogenen satellspezifischen Abweichungen vor und analysiert die Auswirkungen von Korrekturen für Satellitensignalverzerrungen in der Datenverarbeitung. Das Hauptziel besteht darin, die Zuverlässigkeit der AR zu verbessern und die Nutzung aller verfügbaren Signale und Empfängertypen in großflächigen Diensten zu ermöglichen. Anschließend werden neue troposphärische und ionosphärische Verzögerungsanpassungsmodelle für großflächige Anwendungen gemäß den Eigenschaften ihrer Ausbreitungspfade durchgeführt. Darüber hinaus wird die entsprechende atmosphärische Verzögerungsunsicherheit für große Gebiete auf der Grundlage der Anpassungsreste eingeführt. Schließlich wird ein hierarchischer Modus für Augmentationsdienste entwickelt, der die Vorteile des Anpassungsmodells und des Unsicherheitsgitters nutzt, um das Datenvolumen zu reduzieren und regionale Anpassungsreste unter Verwendung des Interpolationsmodells und der ionosphärischen Verzögerungsfehlerfunktion, abhängig von der Netzwerkfähigkeit, zu integrieren. Basierend auf der hierarchischen Augmentation kann die Positionierung in großen Gebieten nicht nur eine schnelle/instantane hochpräzise Konvergenz erreichen, sondern auch den Konflikt zwischen Korrekturvolumen, dargestellter Präzision und Abdeckungsgröße überwinden. Um präzise atmosphärische Verzögerungen abzuleiten und die Positionierung zu beschleunigen, ist es entscheidend, eine zuverlässige und robuste AR über alle Arten von Empfängern und Satellitensignalen zu implementieren. Es zeigt auch die Vorteile der Kalibrierung von satellitensignal- und empfängertypbezogenen satellspezifischen Abweichungen in AR-Lösungen auf. Die Abweichungen im Zusammenhang mit Empfängern in Bezug auf UPD-Produkte werden bewertet und kalibriert, wobei bestätigt wird, dass eine Konsistenz von 0,03 Zyklen bei Wide-Lane-UPD erreicht werden kann. Die Wirksamkeit des vorgeschlagenen Ansatzes wird unter Verwendung von GPS-Satellitensignalen demonstriert, die die AR-Rate um mindestens 10% verbessern und zu zuverlässigeren Ergebnissen führen können. Darüber hinaus wird der Einfluss unterschiedlicher Signalparameter und Korrekturen auf die Erzeugung von Orbit, Uhr und UPD sowie auf die Positionierung und systematische und stochastische Reste der Pseudo-Range-Signale analysiert. Diese Verarbeitungsstrategien bieten flexible Auswahlmöglichkeiten bei der Beobachtung und ermöglichen die Nutzung aller verfügbaren Satellitensignale und Empfängertypen, wodurch eine zuverlässige AR und eine höhere Fixierungsrate ermöglicht wird. Als Ergebnis ist eine AR-Fixierungsrate von über 95% bei allen Stationen in großflächigen Diensten erreichbar. Für eine präzise Modellierung atmosphärischer Verzögerungen über großen Gebieten werden neue Modelle vorgeschlagen, darunter ein troposphärisches Zenith Wet Delay (ZWD)-Modell und ein satellitenweises ionosphärisches Schrägverzögerungsanpassungsmodell. Das troposphärische Verzögerungsmodell berücksichtigt die exponentielle Funktion der vertikalen Änderungen des Wasserdampfs und behebt Modellanomalien in Gebieten mit großen Höhendifferenzen. Das neue ionosphärische Verzögerungsanpassungsmodell verwendet trigonometrische Funktionen, um Unterschiede in den Schrägpfadverzögerungen zwischen dem optimalen Referenzausbreitungspfad und anderen zu beschreiben und erreicht so eine überlegene Modellierungsleistung in großen Gebieten. Die Präzision des Anpassungsmodells, unter Verwendung eines 200 km-Stationen-Netzwerks, zeigt troposphärische ZWD- und ionosphärische Schrägverzögerungen von jeweils 1,3 cm und 8,9 cm mit kleineren Standardabweichungen. Diese neuen Anpassungsmodelle überwinden die Herausforderung, massive Informationen für die Bereitstellung stationsspezifischer Korrekturen zu verarbeiten, und vermeiden eine Zunahme der Anzahl der Koeffizienten. Neben dem Funktionsmodell ist das stochastische Modell, d. h. Unsicherheitsinformationen, entscheidend für die Beschreibung der Qualität der Korrekturen. Die Unsicherheit der atmosphärischen Verzögerung für das großflächige Anpassungsmodell wird auf der Grundlage der Anpassungsreste generiert und in Form von Gitterpunkten dargestellt. Zusätzlich wird die regionale ionosphärische nicht modellierte Restunsicherheit durch die Form einer linearen Funktion repräsentiert, die durch die Beziehung zwischen Entfernung und Interpolationsgenauigkeit durch inter-satellitenkreuz-Verifikation zwischen allen Referenzstationen etabliert wird. Die Unterschiede zwischen Unsicherheitswert und realen Verzögerungen betragen 2,5 cm bzw. 0,5 cm für Gitter- und Funktionsformen. Für Echtzeitanwendungen in großen Gebieten dienen das Anpassungsmodell und die gitterbasierte Atmosphärenunsicherheit als wesentliche Informationen, die die Anforderungen an schnelle Positionierung erfüllen. Durch die weitere Integration von nicht modellierten Resten und Ionosphärenfehlerfunktion wird ein hierarchisches Augmentationsmodell bereitgestellt. Basierend auf dem für große Gebiete etablierten Anpassungsmodell werden nicht modellierte Reste zusätzlich als optionale Kompensation für spezifische Bereiche eingeführt, abhängig von der Größenordnung der Anpassungsreste. Dieser Ansatz führt zu einer Reduktion von 97% der troposphärischen Verzögerung und einer Reduktion von 65% des ionosphärischen Verzögerungsvolumens. Darüber hinaus können unter Nutzung der regionalen hohen Kommunikationsfähigkeit 85,3% aller Lösungen mit Hilfe entsprechender regionaler Kompensation eine sofortige Konvergenz beim ersten Epochenzeitpunkt erreichen. Diese Dissertation schlägt einen großflächigen Augmentationsdienst vor, um den Konflikt zwischen Korrekturvolumen, dargestellter Präzision und Abdeckungsgröße zu überwinden. Sie zeigt die Vorteile eines Augmentationsmodus, der regionale Informationen in großflächige Dienste integriert. Unter diesen Bedingungen kann eine zuverlässigere und schnellere AR-Lösung basierend auf präziser atmosphärischer Verzögerungskorrektur und Unsicherheit in großen Gebieten mit geringeren Anforderungen an das Datenvolumen leicht erreicht werden. Dies ist vorteilhaft für tatsächliche Echtzeitdienste und Anwendungen.

Description: Present day system Earth research utilizes the tool ‘Scientific Drilling’ to access samples and to monitor deep Earth processes that cannot be tackled by other scientific means. Unlike most laboratory experiments or computer modelling, drilling projects are massive field endeavours requiring intense collaboration of researchers with engineers and service providers. In the framework of the International Continental Scientific Drilling Program, ICDP, more than seventy drilling projects have been conducted, from multiyear big research programs to short, smallscale deployments such as lake drilling projects. ICDP has supported these projects not only through grants covering field-related costs, but also through a variety of scientific-technical services and support, as well as active help in data management, outreach and publication. These services are described in this booklet. Due to its instructional character, we call it the ICDP Primer.

Description: Deliverable D2.3 reports the work performed in task 2.3 “Metal complexation and mineral precipitation” within the Reflect project. The task is divided into the subtasks 2.3.1 “Mineral solubility and precipitation kinetics”, 2.3.2 “Mineral precipitation by impedance spectroscopy” and 2.3.3 “Modelling mineral solubility”. A combination of experimental design, performed experiments and numerical modelling have increased the knowledge of mineral solubility and precipitation at high salinity condition in geothermal fluids.

Description: The Mallik Anticline is a geologic structure in the Mackenzie Delta in the Canadian Arctic. Tectonics throughout the Cenozoic, with compressional phases in the early Eocene to the late Miocene, formed this large, domed structure that is today an important source of hydrocarbons. Gas hydrates occur in the clastic sedimentary rocks of the Oligocene to Pleistocene Kugmallite, Mackenzie Bay, and Iperk sequences, which were essentially formed by deltaic processes. The presence of hydrocarbon gases within the permafrost zone in the Canadian Arctic has led to extensive exploration and production activities in the region since the mid-1960s, and the investigations by geologists and geophysicists have already been published in numerous scientific articles to date. This report describes the implementation of the first field-scale 3D static geologic model of the Mallik site, which was created using data from well logs and 2D seismic reflection profiles. The dataset related to this report provides elevation depths and thickness data of the three distinct sequence boundaries Kugmallit-Richards, Mackenzie Bay-Kugmallit and Iperk-Mackenzie Bay as well as fault data from the Mallik site.

Description: The classical way to model the stress state in a rock volume is to estimate displacement boundary conditions that minimize the deviation of the modelled stress state with respect to model-independent stress information such as stress magnitude data. However, these data records are usually subject to significant uncertainties and measurement errors. Hence, it has to be expected that not all stress magnitude data records are representative and can be used in a model. In order to identify unreliable stress data records, the stress state that is based on individual data records is solved and compared with observations at a few discrete locations. While this method works, it is not efficient in that most of the solved model scenarios will be discarded. The solving of the entire model consumes immense amount of computation time for a high-resolution model. Yet, the stress state is required at only a very limited number of locations. For linear geomechanical models it is sufficient to estimate the stress state from three model scenarios with arbitrary, but different displacement boundary conditions. These three results can be used to estimate analytically using a linear regression at discrete points stress states based on user-defined boundary conditions. The tool Fast Automatic Stress Tensor Estimation (FAST Estimation) is a Python function that automatizes this approach. FAST Estimation provides very efficiently the stress states at pre-defined locations for all possible boundary conditions. It does not provide the continuous stress field as provided by a solved geomechanical model. Instead, it is a cost-efficient solution for the rapid assessment of stress states at a limited number of discrete locations based on pre-defined boundary conditions.

Description: During weathering of the deep rocks, many actors act together. This is a property characteristic of the entire “Earth system”. For example, fractures open up, through which water flows that carries carbon and reagants with it from above. New minerals are formed and open up further fractures. Large fractures are also a gateway for microbes from above. They multiply at depths where there is carbon and iron is oxidised. The explorer Alexander von Humboldt stated “Everything is interaction”. Under and on the earth. In our example, soil is created.

Description: Weathering needs fractures in the rock. When two tectonic plates collide, the plates slide against each other. During earthquakes fractures in the rock are created. The microscope reveals tiny cracks running through the rock. These micro-fractures are caused by the movement of the rocks against each other, but also when erosion at the Earth's surface removes the burden of the overlying rock. Fractures are necessary to bring water, reagents, and microbes to depth to weather rocks.

Description: To weather rock, reagents are required. For example, CO2 is found in rainwater as carbonic acid or CO2 is produced by plant roots and by microbes. Through the large fractures carbonic acid and CO2 reach great depth – dissolved in water. Through the fine fractures they reach the interior of the rock. There they dissolve minerals, like the feldspar. New, completely different minerals form, for example clay minerals. They create fine fractures through which water with carbon can penetrate further and the weathering begins again.

Description: Weathering of rock needs water. A rock fractured by tectonic movement is gradually eroded from above, and it moves closer towards the Earth's surface. There it is exposed to precipitation and water begins to penetrate the soil and the layers beneath the soil. Through the tectonic fractures, the water can reach great depths. This is a rapid transport process. At a millimetre scale the water slowly moves into the interior along the smallest cracks that occur there. This is a slow transport process. The water can now weather rocks from the inside.

Description: Living organisms can also weather rocks. There are microorganisms in deep rock – in the "deep biosphere". With flowing water, the microbes are transported from soil through the fractures to depth. Down there, in complete darkness, the microbes live on water, carbon, and energy. They can oxidise iron in minerals and receive energy in the process. The iron-containing minerals are oxidised, carbon is consumed, and more and more microbes are created. This is how the deep biosphere keeps itself alive and weathers the rock at the same time.

Description: Se descubre un misterioso crimen en un almacén. Muchas rocas han sido asesinadas. El detective Hércule Poirot emprende la investigación del caso. Para ello, contrata a un grupo de geo-científicos internacionales que buscan a los "culpables" en una campaña de perforación en los espectaculares paisajes de Chile. Los científicos encuentran pruebas del crimen en laboratorios de investigación y presentan una sorprendente solución al caso de asesinato. Esta película aborda una pregunta científica: ¿Cómo se convierte la roca en suelo en las profundidades de la superficie terrestre? Los cuatro "sospechosos" (es decir, los procesos) son las fracturas en la roca, el flujo de agua, los reactivos químicos y los microbios, los cuales se ven en acción en animaciones. Sin embargo, estas hipótesis no pueden demostrarse directamente, sólo puede demostrarse que son falsas, como una coartada en un caso criminal. Vea la película para averiguar si los investigadores logran resolver el caso. Esta película se produjo en el marco del proyecto germano-chileno "EarthShape – Earth iSurface Shaping by Biota". Puede ver de qué se trata aquí: La piel de la Tierra - donde la vida se encuentra con las rocas

Description: An unbelievable crime is discovered in a storage facility. Rocks have been murdered! Detective Hercule Poirot takes up the investigation. He hires a group of international geo-researchers to search for the "suspects" in a drilling campaign in the spectacular landscapes of Chile. They find evidence of the crime in research laboratories - and present a surprising solution to the murder case. The film addresses a scientific question: how does weathering deep below the Earth's surface turn rock into soil? The four "suspects" (meaning processes) - fractures in the rock, water flow, chemical reagents, and microbes are seen in action in animations. However, they only serve as hypotheses that cannot be directly proven. They can only be shown to be false – just like an alibi in a criminal case. Watch the movie to see whether the researchers succeed. The film was produced as part of the German-Chilean project "EarthShape – Earth Surface Shaping by Biota". Another video can be seen here: The Skin of the Earth - Where Life Meets Rocks

Description: The Collisional Orogeny in the Scandinavian Caledonides (COSC) scientific drilling project characterises the structure and orogenic processes involved in a major collisional mountain belt by multi-disciplinary geoscientific research. Located in western central Sweden, the project has drilled its second fully cored borehole COSC-2 in 2020. It extends the COSC composite geological section through the nappes of the Caledonian Lower Allochthon, the main décollement and the upper kilometre of basement rocks. COSC-2 targets include the characterisation of orogen-scale detachments, the impact of orogenesis on the basement below the detachment, and the Early Cambrian palaeoenvironment on the outer margin of palaeocontinent Baltica. This is complemented by research on heat flow, groundwater flow, and characterisation of the microbial community in the present hard rock environment of the relict mountain belt. COSC-2 successfully and within budget recovered a continuous drill core to 2276 m depth. The retrieved geological section is partially different from the expected geological section with respect to the depth to the main décollement and the expected rock types. The intensity of deformation in the rocks in the upper part of the drill core might impede the analysis of the Early Cambrian palaeoenvironment. However, the superb quality of the drill core and the borehole will facilitate research on the remaining targets and beyond. Although on-site science was reduced due to Covid-19 related restrictions, COSC-2 drilling was complemented by extensive downhole surveys. However, the geological description of the drill core and the sampling party were severely delayed, with the later being held about two years after drilling, concluding the operational phase of the project.

Description: This report describes the activities performed within Task 1.2 “Report on gas solubility and degassing kinetic (type C)” until the end of month 40 of the REFLECT project. Two series of experiments have been carried out that assess the degassing process of type C geothermal fluids respectively in bulk and porous media. This has resulted in an improved understanding of the process and the associated physical phenomena by utilizing experimental equipment and data analysis tools specifically created for this task.

Description: This report describes the activities performed within Task 1.3 “Summary of gas solubility and degassing kinetics (type A)” until the end of month 39 of the REFLECT project. Two series of experiments have been carried out that assess the degassing process of type A geothermal fluids respectively in bulk and porous media. This has resulted in an improved understanding of the process and the associated physical phenomena by utilizing experimental equipment and data analysis tools specifically created for this task.

Description: All datasets provided in the operational dataset (DOVE-Phase 1 Scientific Team et al., 2023b) of the ICDP project DOVE phase 1 (ICDP 5068) consist of metadata, data and/or images. Here, we summarize explanations on the tables, data and images exported from the database of the project (mDIS DOVE) as well as some basic explanations on identifiers used in ICDP, depths corrections and measurements that are integrated into the dataset.

Description: The 3D geomechanical-numerical modelling aims at a continuous description of the stress state in a subsurface volume. The model is fitted to the model-independent stress data records by adaptation of the displacement boundary conditions. This process is herein referred to as model calibration. Depending on the amount of available stress data records and the complexity of the model the calibration can be a lengthy process of trial-and-error to estimate the best-fit boundary conditions. The tool FAST Calibration (Fast Automatic Stress Tensor Calibration) is a Matlab script that facilitates and speeds up this calibration process. By using a linear regression it requires only three test model scenarios with different displacement boundary conditions to calibrate a geomechanical-numerical model on available stress data records. The differences between the modelled and observed stresses are used for the linear regression that allows to compute the displacement boundary conditions required for the best-fit estimation. The influence of observed stress data records on the best-fit displacement boundary conditions can be weighted. Furthermore, FAST Calibration provides a cross checking of the best-fit estimate against indirect stress information that cannot be used for the calibration process, such as the observation of borehole breakouts or drilling induced fractures. In order to bridge the scale gap between a regional stress model and a local reservoir model, the multistage calibration procedure is applied where a local model is calibrated solely on the stress state provided by a regional model. FAST Calibration provides the necessary tools and guidelines. The script files are provided for download at http://github.com/MorZieg/FAST_Calibration. Tab. 0-1 gives an overview of the folder structure and input files with a short explanation.

Description: A detailed understanding of the geological structural elements is vital for geothermal reservoir exploration. Among existing geophysical methods, seismic methods are most commonly used for subsurface imaging due to the relatively high resolution at significant depths. However, seismic campaigns are rather expensive. The high upfront investment cost represent a substantial barrier for heat/electricity production from geothermal resources. Thus, developing new techniques is vital for further reduction in exploration and drilling costs, which is necessary for geothermal project advancements. Within the framework of the joint research project RissDom-A, the subsurface exploration of the Groß Schönebeck in-situ geothermal laboratory, situated 40 km north of Berlin, a seismic survey was carried out using 3D surface seismic and 3D vertical seismic profiling methods. VSP was acquired with wireline distributed acoustic sensing (DAS), which allows converting a freely suspended fibre optic cable inside a borehole into a dense array of seismic sensors to record strain or strain rate. In this thesis, the applicability of this method is evaluated for seismic imaging of an enhanced geothermal reservoir. The survey design consisted of 61 vibrator source positions organised in a spiral pattern around the boreholes E GrSk 3/90 and Gt GrSk 4/05 in such a way to optimise the illumination of the reservoir. The DAS recordings have an excellent signal-to-noise ratio (40-50 dB around 1000 m, 4-10 dB at around 4200 m). This data quality was reached with 16 vertical stacking rates on average. In addition, a comparison with a conventional accelerometer measurement showed excellent waveforms agreement. The acquisition campaign was conducted within four days, illustrating that wireline DAS is very attractive both from a data quality point of view and economically. A 3D VSP processing workflow was adapted to the Groß Schönebeck specifics and applied to the data. Particular depth ranges of the recorded data are subjected to strong coherent noise, which has a distinct pattern both in the time and the frequency domain. This type of noise is related to the poor coupling conditions of the cable in the borehole. For signal-to-noise ratio improvement, several existing denoising methods have been analysed. After coupling noise filter function assessment, a new noise elimination method was proposed based on the matching pursuit decomposition technique with Gabor atoms. The developed processing routine was uniformly applied to the whole dataset, which significantly improved the data quality, and as a result, migration images created using the Kirchhoff depth migration algorithm with restricted aperture. After data processing, a detailed subsurface analysis in the vicinity of the boreholes at the Groß Schönebeck was carried out using the 3D DAS VSP image. The resulting borehole cube data resolve new features that could not be imaged with the 3D surface seismic cube due to the lower resolution of the 3D surface seismic cube, with respect to the 3D VSP cube. Complex thin interlaying of the Upper Rotliegend horizons has been revealed in the geothermal reservoir section, allowing for the first time to access and characterise so-called “phantom horizons” which are typical for the Brandenburg area, Germany. Furthermore, the borehole cube provided new insights on two main targets for future exploration. The 3D DAS VSP cube revealed an intra-reservoir structure inside the Elbe reservoir sandstone layer, which could represent porous parts of a stacked fluvial sandstone body. The estimated thickness of this structure varies between 25 to 40 m, which is thinner than previous estimations. Additionally, a lower Rotliegend unconformity (at around 4.2 km depth) was mapped in the study area. This allowed to estimate the possible thickness of the vulcanite sections below this boundary. VSP data thus helped to reduce the uncertainty and exploration risks by providing valuable information for the geological characterisation of the Groß Schönebeck site. With this successful case study I demonstrated that fibre optic data could significantly contribute to the characterisation of deep geothermal reservoirs. Consequently, presented results contribute to the wireline distributed acoustic sensing method promotion to develop modern, reliable and economically affordable exploration methods for geothermal energy assessments.

Description: Ein detailliertes Verständnis der geologischen Strukturelemente ist für die Erkundung geothermischer Reservoire unerlässlich. Unter den bekannten geophysikalischen Methoden werden vor allem seismische Untersuchungen zur Abbildung des Untergrunds aufgrund der vergleichsweise hohen Auflösung bis in große Tiefen genutzt. Seismikkampagnen sind jedoch verhältnismäßig teuer. Die hohen Anfangsinvestitionskosten bilden eine erhebliche Hürde für die Wärme- und Stromproduktion aus geothermischen Ressourcen. Daher ist die Entwicklung neuer Techniken zur Reduktion von Exploarations- und Bohrkosten für die notwendige Förderung geothermischer Projekte essenziell. Im Rahmen des Verbundforschungsprojekts RissDom-A, der Untergrunderkundung des 40 km nördlich von Berlin gelegenen Groß Schönebeck in-situ Geothermielabors, wurden seismische Messungen durchgeführt, bestehend aus einer 3D-Oberflächen- und einer 3D-Bohrlochseismik. Die VSP-Daten (Vertical Seismic Profiling) wurden mittels kabelgebundenem DAS (Wireline Distributed Acoustic Sensing) aufgezeichnet, was die Umwandlung eines frei im Bohrloch hängenden faseroptischen Kabels in ein dichtes Array seismischer Sensoren zur Registrierung von Strain oder Strain-Rate erlaubt. In dieser Doktorarbeit wird die Anwendbarkeit dieser Methodik für die seismische Abbildung von EGS-Reservoiren (Enhanced Geothermal System) eingehend ausgewertet. Die Messkonfiguration bestand aus 61 Vibrator-Quellpositionen, die in einem spiralförmigen Pattern um die beiden Bohrlöcher E GrSk 3/90 und Gt GrSk 4/05 derart verteilt wurden, dass eine optimale Durchschallung des Reservoirs gegeben war. Die DAS-Aufzeichnungen zeigen ein exzellentes Signal/Rausch-Verhältnis (40-50 dB bei ca. 1000 m, 4-10 dB bei ca. 4200 m). Diese Datenqualität konnte aufgrund der durchschnittlich 16-fachen vertikalen Stapelrate erzielt werden. Zu Vergleichswecken zusätzlich vorgenommene konventionelle Beschleunigungsaufnehmer- Messungen zeigen eine sehr gute Übereinstimmung der Wellenformen. Die Messkampagne umfasste vier Tage, was die Attraktivität von Wireline-DAS unter sowohl qualitativen als auch ökonomischen Aspekten überzeugend demonstriert. Eine 3D-VSP Bearbeitungssequenz wurde an die Besonderheiten der Groß Schönebeck Messungen angepasst und auf die Daten angewendet. Einzelne Tiefenbereiche der Aufzeichnungen enthalten starke kohärente Störsignale, die ein ausgeprägtes Muster sowohl im Zeitals auch im Frequenzbereich aufweisen. Diese Art Noise ist auf eine ungenügende Ankopplung des Kabels im Bohrloch zurückzuführen. Zur Verbesserung des Signal/Rausch-Verhältnisses wurden verschiedene gebräuchliche Unterdrückungsmethoden untersucht. Nach Analyse der Kopplungsnoise-Filterfunktion konnte eine neuartige Methode zur Rauschunterdrückung etabliert werden, welche auf einer Matching-Pursuit Dekompositionstechnik mit Gabor-Atomen basiert. Der auf diese Weise entwickelte Prozessierungsansatz wurde gleichmäßig auf den gesamten Datensatz angewendet, was die Datenqualität signifikant erhöhte, so dass in der Folge Migrationsabbilder unter Verwendung eines Kirchhoff-Tiefenmigrationsverfahrens mit beschränkter Apertur erzeugt werden konnten. Nach erfolgter Datenbearbeitung wurde anhand der DAS/VSP 3D-Daten eine detaillierte Untergrundanalyse im Bereich der Groß Schönebeck Bohrlöcher durchgeführt. Das resultierende Bohrlochaten-Volumen löst viele neue Details auf, die mit dem 3D-Volumen der Oberflächenseismik aufgrund des vergleichsweise geringeren Auflösungsvermögens nicht abgebildet wurden. So konnten in der geothermischen Reservoirsektion komplexe dünnschichtige Einlagerungen im Oberen Rotliegend nachgewiesen werden, die erstmalig die Ansprache und Charakterisierung sogenannter „Phantom-Horizonte“ ermöglichen, wie sie typisch für das Gebiet Brandenburg, Deutschland sind. Weiterhin liefert der Bohrlochdaten-Kubus neue Einblicke auf zwei Hauptziele zukünftiger Explorationen. Das DAS/VSP 3D-Datenvolumen zeigt eine Intra-Reservoir Strukur innerhalb der Elbe-Sandstein Schicht, die poröse Anteile eines gestapelten fluvialen Sandsteinkörpers repräsentieren könnte. Die geschätzte Mächtigkeit dieser Struktur variiert zwischen 25 und 40 m, was dünner ist, als zuvor angenommen. Des weiteren konnte im Untersuchungsgebiet eine Diskordanz im Unteren Rotliegend (in einer Tiefe von ca 4.2 km) kartiert werden. Dies erlaubt es, die mögliche Mächtigkeit der Vulkanite darunter abzuschätzen. Somit helfen die VSP-Daten dabei, die Unklarheiten und das Explorationsrisiko zu reduzieren, indem sie wertvolle Informationen zur geologischen Charakterisierung des Groß Schönebeck Standorts liefern. Mit dieser Fallstudie konnte ich erfolgreich demonstrieren, dass mithilfe faseroptischen Kabels gewonnene Messdaten zur Charakterisierung geothermischer Reservoire maßgeblich beitragen können. In der Konsequenz fördern die präsentierten Ergebnisse die Bedeutung von Wireline Distributed Acoustic Sensing im Hinblick auf eine moderne, verlässliche und ökonomische Explorationsmethode für geothermische Energiekonzepte.

Description: This report presents the European High-Resolution Exposure (EHRE) model, which we created by combining the state-of-the art exposure model of the European Seismic Risk Model 2020 (ESRM20) with building footprints and data from OpenStreetMap previously processed by OpenBuildingMap. We present the method used to generate the model and the software we developed for this purpose, as well as a number of outputs that give an overview of what the model consists of and enable discussion.

Description: This deliverable summarizes the optimization workflow to determine the optimum operational controls for the geothermal assets operation considering the uncertainties in the brine composition. The developed models for coupling hydrodynamics with chemistry and uncertainty quantification workflow for estimating the risk of scaling in geothermal plants were integrated with a stochastic optimization model. Results showed the demonstration of such an integrated workflow applied to a scaling precipitation case study and possible variations in operational decisions due to uncertainties in the brine composition.

Description: This document presents the application of coupled hydrogeochemical codes to the modelling of geothermal fluid reactivity in tubings during the production of geothermal energy. Two codes are used on two examples of fluids: one is very concentrated with a moderate temperature (no phase changes during the pumping) and one hot fluid with a lower salinity (with phase change). Results focus on the risks of scaling during the exploitation.

Description: Risk maps are created with the objective of providing improved operational advice on scaling mitigation. The issue of prevailing uncertainties and variations in fluid and gas data had to be tackled to provide accurate model predictions and risk assessments. The developed risk map workflow is demonstrated for calcite scaling risks of the West-Netherlands Basin.

Description: This report documents the drilling operations of the Early Jurassic Earth System and Timescale scientific drilling project (JET, ICDP Project: 5065). The wells 5065_1_A, 5065_1_B, 5065_1_A were drilled in 2019-2021 with the support of the International Continental Scientific Drilling Program (ICDP) and the UK Natural Environment Research Council (NERC). Alternatively, the site is known as Prees 2 (Holes A – C). Prees 1 was a nearby hydrocarbon exploration well drilled by Trend Petroleum in 1972–1973. The project aims to construct a fully integrated and astronomically calibrated timescale for the Early Jurassic, a time in Earth history during which important physical, chemical, and biological elements of the modern Earth system were initiated. The JET drilling campaign supplements the earlier Llanbedr (Mochras Farm) borehole (1967 – 1969) in NW Wales – usually known as Mo-chras – which recovered a 1.3 km thick succession comprising the Rhaetian (Upper Triassic), Hettangian, Sinemurian, Pliensbachian and Toarcian (Lower Jurassic) stages (Woodland, 1971; Hesselbo et al., 2013). Using the combined framework of Prees and Mochras, internal and ex-ternal forcing factors on the Earth system will be documented and quantified for major palaeo-environmental events, such as the Late Triassic mass extinction and the Early Toarcian Oceanic Anoxic Event, and for the more stable ‘background’ state.

Description: Two recent tsunamis in late 2018, in Sulawesi and Anak Krakatau, Indonesia, strikingly demonstrated the high vulnerability of communities to tsunamis induced by landslides and volcanic mechanisms. Both tsunamis were the result of a chain (cascade) of events: on 28 September in Palu, on the island of Sulawesi, the cascade consisted of a sequence of earthquake - landslide - tsunami, while on 22 December, after a prolonged period of volcanic activity, a flank failure occurred on Anak Krakatau, which in turn triggered a tsunami (Walter et al, 2019). In both cases, the resulting tsunamis caught the local population largely unprepared and caused a high number of fatalities. This has been attributed to the limited understanding of tsunami generation from mechanisms other than fault rupture and the lack of an effective tsunami warning system for non-seismic events. Both events have raised questions in the Indonesian society and among the relevant authorities about appropriate strategies for improved preparedness, early warning and mitigation for such events. The German-Indonesian project "TsunamiRisk" aims to help answer these questions through applied geoscientific and social science research aimed at developing policy recommendations and enabling transfer into practice. The perspective of local communities must be given special consideration, as it is ultimately they who are confronted with the direct impacts of such events on the one hand and who must implement better preparation and long-term mitigation on the ground on the other. Therefore, the project investigates the specific framework conditions as well as existing experiences in Indonesian communities with previous earthquake/tsunami events in order to support the discussion about adequate strategies and approaches for preparedness, early warning and mitigation of non-seismic tsunami hazards at the local level. The starting point for all this is to have a better understanding of the tsunami threats that communities face. The present study is intended to make a contribution to this.

Description: This deliverable contains the raw data that constitutes the database of microbial diversity and organic compounds in geothermal fluids used for electricity production generated during the project.

Description: Report of design and test results of downhole sampling.

Description: We provide new thermodynamic and kinetic data concerning the dissolution and precipitation of silica in hot and superhot geothermal systems. Different methods were applied, including traditional photometric methods and in situ Raman and conductimetric methods. The studies covered the interactions of silica with both pure water and saline solutions. The kinetics of silica polymerisation were studied in the presence of various metal ions and at different pH values, informed by an analysis of real geothermal water samples from the Tuzla region of Türkiye.

Description: The International Celestial Reference System (ICRS) is the reference system used for astrometry and geodesy in space. Its realizations are the International Celestial Reference Frames (ICRFs). The latest realizations are ICRF3 S/X, ICRF3 K, and ICRF3 X/Ka at radio frequencies observed by geodetic very long bThe International Celestial Reference System (ICRS) is the reference system used for astrometry and geodesy in space. Its realizations are the International Celestial Reference Frames (ICRFs). The latest realizations are ICRF3 S/X, ICRF3 K, and ICRF3 X/Ka at radio frequencies observed by geodetic very long baseline interferometry (VLBI), and Gaia-CRF3 from observations by the Gaia spacecraft at optical frequencies. The ICRFs are independently derived catalogs of mean positions (and proper motions as well as parallaxes in case of Gaia) of distant compact extragalactic sources with approximately comparable precision. Within the error bounds, the different observation setups should ideally produce identical source positions. However, previous research discovered variances related to the variable nature of the sources as a function of frequency and time. A deeper understanding of the individual source position differences as well as the alignment of the ICRFs in terms of global systematic source position differences benefits the large ICRF and Gaia user community, such as geodetic VLBI for connecting VLBI products across frequencies. This work adds several case studies to the existing research on the comparison and the alignment of the ICRFs. At optical frequencies, the set of ICRF3 counterparts in the Gaia spacecraft’s Early Data Release 3 (Gaia EDR3, including Gaia-CRF3) and in Gaia DR2, the predecessor of Gaia EDR3, are investigated. The position differences of the individual counterparts at the various frequencies are re-evaluated, focusing on the correlation of the normalized distances, offset directions, and global systematic differences with the number of VLBI observations or the extent of radio source structure. The individual VLBI and Gaia position offsets tend to be in the same direction, especially in case of significant offsets. It is shown that large normalized position offsets are related to sources with large radio structure. The global systematic differences, which are an order of magnitude smaller than the individual differences, can be accurately determined, especially if the set of counterparts has been defined. A Celestial Reference Frame (CRF) determined from S/X observations from the same time interval as Gaia DR2 does not indicate any improvements in the alignment of Gaia DR2 compared to ICRF3 S/X. Since the alignment of Gaia DR2 and Gaia EDR3 depends on the visual magnitude G and the radio sources in ICRF3 are optically faint, the alignment of the bright fraction (G ≤ 13 mag) of the Gaia data releases to ICRF3 requires additional verification. The approach and data of Lindegren (2020a) are adopted, who used optically bright radio stars to test the alignment. Since the resolution of VLBI and Gaia is small enough to detect their proper motions, they must be included in the alignment test and a time variability of the alignment (spin) must also be estimated. However, these results are not yet accurate enough compared to the expected uncertainties of the individual sources astrometry in the final Gaia data release for this G magnitude range. In this work, these VLBI data of radio stars are homogenized, and a more realistic error budget for the VLBI positions is established. New, dedicated VLBI observations of bright radio stars were carried out to obtain more urgently needed VLBI positions for the determination of the alignment. The positions are included in two ways: once as absolute one-epoch positions and once as relative positions in order to derive new precise models of stellar motion whenever possible. A significant spin around the Y axis was determined for both Gaia DR2 and Gaia EDR3, albeit the rotations in this direction are still the least well determined. Among other aspects, the accuracy of the results, the effect of nonlinear proper motion, and a G magnitude dependence within the bright fraction are investigated. The effect of possible future VLBI observations of radio stars on the alignment is tested. In summary, this work evaluates the accuracy of the alignment of the current ICRFs. It furthermore highlights the need to accurately assess VLBI observations of radio stars in the context of the alignment of the Gaia bright frame with ICRF3 and demonstrates how this can be accomplished.

Description: Das International Celestial Reference System (ICRS) ist das Himmelsreferenzsystem, das in der Astrometrie und Geodäsie verwendet wird. Seine Realisierungen sind die International Celestial Reference Frames (ICRFs). Die jüngsten Realisierungen sind im Radiofrequenzbereich der ICRF3 S/X, der ICRF3 K und der ICRF3 X/Ka, welche mit Hilfe von geodätischer very long baseline interferometry (VLBI) beobachtet werden. Außerdem ist es im optischen Frequenzbereich der Gaia-CRF3, welcher aus Beobachtungen des Gaia Weltraumteleskops stammt. DDas International Celestial Reference System (ICRS) ist das Himmelsreferenzsystem, das in der Astrometrie und Geodäsie verwendet wird. Seine Realisierungen sind die International Celestial Reference Frames (ICRFs). Die jüngsten Realisierungen sind im Radiofrequenzbereich der ICRF3 S/X, der ICRF3 K und der ICRF3 X/Ka, welche mit Hilfe von geodätischer very long baseline interferometry (VLBI) beobachtet werden. Außerdem ist es im optischen Frequenzbereich der Gaia-CRF3, welcher aus Beobachtungen des Gaia Weltraumteleskops stammt. Die ICRFs sind unabhängig voneinander abgeleitete Kataloge mittlerer Positionen (und Eigenbewegungen als auch Parallaxen im Falle von Gaia) entfernter kompakter extragalaktischer Quellen mit annähernd vergleichbarer Genauigkeit. Innerhalb der Fehlergrenzen sollten die verschiedenen Beobachtungsmethodiken idealerweise zu identischen Quellenpositionen führen. In früheren Untersuchungen wurden jedoch Abweichungen festgestellt, die mit der frequenz- und zeitvariablen Quellenstruktur zusammenhängen. Ein tieferes Verständnis der individuellen Positionsunterscheide der Quellen als auch der Unterschiede in der Orientierung der ICRFs mittels globaler systematischer Positionsunterschiede der Quellen kommt der großen Nutzergruppe von ICRF und Gaia zugute, wie z. B. der geodätischen VLBI für die Zusammenführung von VLBI-Produkten über Frequenzen hinweg. Diese Arbeit ergänzt die bestehenden Forschungsarbeiten über den Vergleich und die Orientierung der ICRFs um mehrere Fallstudien. Im optischen Frequenzbereich werden die ICRF3-Gegenstücke im Early Data Release 3 (Gaia EDR3, einschließlich Gaia-CRF3) der Gaia Raumsonde und im Gaia DR2, dem Vorgänger von Gaia EDR3, untersucht. Die Positionsunterschiede der einzelnen Gegenstücke für die verschiedenen Frequenzen werden neu bewertet, wobei der Schwerpunkt auf der Korrelation der normalisierten Entfernungen, der Richtungen der Positionsdifferenzen und der globalen systematischen Unterschiede mit der Anzahl der VLBI-Beobachtungen sowie dem Ausmaß der Radioquellenstruktur liegt. Die individuellen VLBI- und Gaia-Positionsunterschiede bevorzugen die selbe Richtung, insbesondere im Falle signifikanter Differenzen. Es wird gezeigt, dass große normalisierte Positionsunterschiede auf Quellen mit großer Radioquellenstruktur zurückzuführen sind. Die globalen systematischen Abweichungen, die um eine Größenordnung geringer sind als die individuellen Differenzen, können genau bestimmt werden. Dies gilt insbesondere wenn die Teilmenge der verwendeten Gegenstücke vorher definiert wurde. Ein Celestial Reference Frame (CRF), der aus S/X-Beobachtungen des selben Zeitintervalls wie Gaia DR2 ermittelt wurde, zeigt keine Verbesserungen in der Ausrichtung von Gaia DR2 im Vergleich zu ICRF3 S/X. Da die Orientierung von Gaia DR2 und Gaia EDR3 von der scheinbaren Helligkeit G ab- hängt und die Radioquellen des ICRF3 eine geringe scheinbare Helligkeit aufweisen, muss die Ausrichtung des hellen Anteils (G ≤ 13 mag) der Gaia-Daten auf den ICRF3 zusätzlich überprüft werden. In dieser Arbeit werden der Ansatz und die Daten von Lindegren (2020a) übernommen, der zur Überprüfung der Orientierung scheinbar helle Radiosterne verwendete. Da die Auflösung von VLBI und Gaia klein genug ist, um Eigenbewegungen von Sternen zu erkennen, müssen diese in den Orientierungstest einbezogen und auch eine zeitliche Variabilität der Orientierung geschätzt werden. Allerdings sind diese Ergebnisse bisher nicht genau genug im Vergleich zu den erwarteten Genauigkeiten der Astrometrie der einzelnen Quellen des hellen Anteils in der endgültigen Gaia-Datenveröffentlichung. In dieser Arbeit werden die vorhandenen VLBI-Daten der Radiosterne homogenisiert und es wird ein realistischeres Fehlerbudget für die VLBI-Positionen aufgestellt. Es wurden neue, gezielte VLBI-Beob-achtungen von hellen Radiosternen durchgeführt, um mehr dringend benötigte VLBI-Positionen für eine bessere Bestimmung der Orientierung zu erhalten. Die Positionen wurden auf zwei verschiedene Arten integriert: einmal als absolute Positionen aus einer Beobachtungsepoche und einmal als relative Positionen, um wann immer möglich neue präzise Modelle der Sternbewegung abzuleiten. Sowohl für Gaia DR2 als auch für Gaia EDR3 wurde eine signifikante zeitabhängige lineare Rotation um die Y -Achse ermittelt, wenngleich die Rotationen in dieser Richtung noch die geringste Genauigkeit aufweisen. Unter anderem werden die Genauigkeit der Ergebnisse, die Auswirkung der nichtlinearen Eigenbewegung und die Abhängigkeit von der scheinbaren Helligkeit innerhalb des hellen Anteils untersucht. Der Einfluss möglicher zukünftiger VLBI-Beobachtungen von Radiosternen auf die Orientierungsbestimmung wird getestet. Zusammenfassend evaluiert diese Arbeit die Genauigkeit der Orientierung der aktuellen ICRFs. Sie unterstreicht darüber hinaus die Notwendigkeit, VLBI-Beobachtungen von Radiosternen im Zusammenhang mit der Orientierung des hellen Gaia-Referenzrahmens zu ICRF3 genau zu prüfen, und zeigt, wie dies erreicht werden kann.ie ICRFs sind unabhängig voneinander abgeleitete Kataloge mittlerer Positionen (und Eigenbewegungen als auch Parallaxen im Falle von Gaia) entfernter kompakter extragalaktischer Quellen mit annähernd vergleichbarer Genauigkeit. Innerhalb der Fehlergrenzen sollten die verschiedenen Beobachtungsmethodiken idealerweise zu identischen Quellenpositionen führen. In früheren Untersuchungen wurden jedoch Abweichungen festgestellt, die mit der frequenz- und zeitvariablen Quellenstruktur zusammenhängen. Ein tieferes Verständnis der individuellen Positionsunterscheide der Quellen als auch der Unterschiede in der Orientierung der ICRFs mittels globaler systematischer Positionsunterschiede der Quellen kommt der großen Nutzergruppe von ICRF und Gaia zugute, wie z. B. der geodätischen VLBI für die Zusammenführung von VLBI-Produkten über Frequenzen hinweg. Diese Arbeit ergänzt die bestehenden Forschungsarbeiten über den Vergleich und die Orientierung der ICRFs um mehrere Fallstudien. Im optischen Frequenzbereich werden die ICRF3-Gegenstücke im Early Data Release 3 (Gaia EDR3, einschließlich Gaia-CRF3) der Gaia Raumsonde und im Gaia DR2, dem Vorgänger von Gaia EDR3, untersucht. Die Positionsunterschiede der einzelnen Gegenstücke für die verschiedenen Frequenzen werden neu bewertet, wobei der Schwerpunkt auf der Korrelation der normalisierten Entfernungen, der Richtungen der Positionsdifferenzen und der globalen systematischen Unterschiede mit der Anzahl der VLBI-Beobachtungen sowie dem Ausmaß der Radioquellenstruktur liegt. Die individuellen VLBI- und Gaia-Positionsunterschiede bevorzugen die selbe Richtung, insbesondere im Falle signifikanter Differenzen. Es wird gezeigt, dass große normalisierte Positionsunterschiede auf Quellen mit großer Radioquellenstruktur zurückzuführen sind. Die globalen systematischen Abweichungen, die um eine Größenordnung geringer sind als die individuellen Differenzen, können genau bestimmt werden. Dies gilt insbesondere wenn die Teilmenge der verwendeten Gegenstücke vorher definiert wurde. Ein Celestial Reference Frame (CRF), der aus S/X-Beobachtungen des selben Zeitintervalls wie Gaia DR2 ermittelt wurde, zeigt keine Verbesserungen in der Ausrichtung von Gaia DR2 im Vergleich zu ICRF3 S/X. Da die Orientierung von Gaia DR2 und Gaia EDR3 von der scheinbaren Helligkeit G ab- hängt und die Radioquellen des ICRF3 eine geringe scheinbare Helligkeit aufweisen, muss die Ausrichtung des hellen Anteils (G ≤ 13 mag) der Gaia-Daten auf den ICRF3 zusätzlich überprüft werden. In dieser Arbeit werden der Ansatz und die Daten von Lindegren (2020a) übernommen, der zur Überprüfung der Orientierung scheinbar helle Radiosterne verwendete. Da die Auflösung von VLBI und Gaia klein genug ist, um Eigenbewegungen von Sternen zu erkennen, müssen diese in den Orientierungstest einbezogen und auch eine zeitliche Variabilität der Orientierung geschätzt werden. Allerdings sind diese Ergebnisse bisher nicht genau genug im Vergleich zu den erwarteten Genauigkeiten der Astrometrie der einzelnen Quellen des hellen Anteils in der endgültigen Gaia-Datenveröffentlichung. In dieser Arbeit werden die vorhandenen VLBI-Daten der Radiosterne homogenisiert und es wird ein realistischeres Fehlerbudget für die VLBI-Positionen aufgestellt. Es wurden neue, gezielte VLBI-Beob-achtungen von hellen Radiosternen durchgeführt, um mehr dringend benötigte VLBI-Positionen für eine bessere Bestimmung der Orientierung zu erhalten. Die Positionen wurden auf zwei verschiedene Arten integriert: einmal als absolute Positionen aus einer Beobachtungsepoche und einmal als relative Positionen, um wann immer möglich neue präzise Modelle der Sternbewegung abzuleiten. Sowohl für Gaia DR2 als auch für Gaia EDR3 wurde eine signifikante zeitabhängige lineare Rotation um die Y -Achse ermittelt, wenngleich die Rotationen in dieser Richtung noch die geringste Genauigkeit aufweisen. Unter anderem werden die Genauigkeit der Ergebnisse, die Auswirkung der nichtlinearen Eigenbewegung und die Abhängigkeit von der scheinbaren Helligkeit innerhalb des hellen Anteils untersucht. Der Einfluss möglicher zukünftiger VLBI-Beobachtungen von Radiosternen auf die Orientierungsbestimmung wird getestet. Zusammenfassend evaluiert diese Arbeit die Genauigkeit der Orientierung der aktuellen ICRFs. Sie unterstreicht darüber hinaus die Notwendigkeit, VLBI-Beobachtungen von Radiosternen im Zusammenhang mit der Orientierung des hellen Gaia-Referenzrahmens zu ICRF3 genau zu prüfen, und zeigt, wie dies erreicht werden kann.

Description: Space geodetic techniques contribute significantly to enhancing our understanding of the Earth system. These techniques include Very Long Baseline Interferometry (VLBI), Global Navigation Satellite System (GNSS), Satellite Laser Ranging (SLR), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS). The primary objective of these space geodetic techniques is to establish an accurate Terrestrial Reference Frame (TRF). Since each technique has its strengths and weaknesses, a combination of space geodetic techniques is employed to overcome the weaknesses in TRF determination. The current TRF, known as the International Terrestrial Reference Frame 2020 (ITRF2020), is determined with a combination of space geodetic techniques through station coordinate parameters at the co-location sites using local ties, which represent the difference between the station coordinates of a space geodetic technique at a co-location site. According to the scientific-driven requirements of the Global Geodetic Observing System (GGOS), the TRF needs to be established with an accuracy level of 1 mm. However, the ITRF2020 has not yet reached this scientific requirement. Therefore, another perspective needs to be investigated in order to reach the scientific-driven requirement for TRF determination. Microwave-based space geodetic techniques, such as VLBI and GNSS, observe under the same atmospheric conditions and are also included as a parameter in the adjustment process. Therefore, similar to station coordinates, this parameter can also be combined using ties. The ties for tropospheric parameters are referred to as "tropospheric ties". Unlike the local ties, which are directly measured using a total station or other distance measurements at the reference point of the space geodetic technique, tropospheric ties can only be derived through a model. Currently, two different approaches can be used to derive tropospheric ties. The first approach involves using an analytical model with meteorological data from different sources, such as meteorological sensors at the site, a Numerical Weather Model (NWM), and an empirical meteorological model. The second approach involves using the ray-tracing technique through a refraction field of NWM. However, since tropospheric ties can only be derived from the model, their accuracy is limited. To improve their accuracy, it is necessary to address the systematic effects that cause a discrepancy between the observed tropospheric parameter differences and tropospheric ties. This thesis investigates this discrepancy using the GNSS and VLBI intra/inter technique comparison of tropospheric parameters. The results indicate that the discrepancy is caused by the GNSS instrument, specifically the antenna and radome, in zenith total delay (ZTD) differences. On the other hand, the horizontal gradient difference is affected by multipath effects that occur at low-elevation observations, rather than the instrument. This study observes no systematic effect in VLBI due to the instrument. The systematic effect in tropospheric parameters due to the instrument is referred to as instrumental bias. To prove this hypothesis, a GNSS co-location site experiment was conducted. The experiment reveals that the instrumental bias in GNSS-derived ZTD parameters originates from the instrument. Furthermore, the bias in GNSS-derived horizontal gradients comes from the multipath effect that occurs at low-elevation observations. To address the instrumental bias, another GNSS co-location experiment was conducted. This experiment employed a vertical steering pole to minimize the height difference of various antenna phase centers to a few millimeters level during antenna changing. The experiment successfully kept the reference point position for each experiment antenna at the same position within a 2 mm level. Thus, the remaining bias in GNSS-derived tropospheric parameters is attributed to the instrumental bias. This study demonstrates the capability and limitations of tropospheric ties through a combination of VLBI and GNSS on the Normal Equation (NEQ) level. The combination of VLBI and GNSS with tropospheric ties shows a prominent improvement in station coordinates and tropospheric parameters. A VLBI intra-technique combination during CONT14 demonstrated improvements in station coordinates and tropospheric parameters for two telescopes at the Hobart co-location site. Tropospheric ties demonstrate a capability as alternative ties when the local ties are of poor quality, particularly the height component. The results indicate that VLBI received the most benefit when combining tropospheric parameters with tropospheric ties in both station coordinates and tropospheric parameters. The study of proper temporal resolution for applying tropospheric ties was investigated. The results show similar results for all scenarios in both station coordinates and troposphere parameters. For the first time, a combination of GNSS and VLBI utilizing tropospheric ties with an instrumental bias correction is performed. The results show a significant improvement in station coordinates, particularly in VLBI. Furthermore, applying tropospheric ties with an instrumental bias correction considerably reduces the discrepancy between local ties and the space geodetic technique solution. However, there is no improvement in tropospheric parameters from using instrumental bias correction for tropospheric ties. The study also evaluates the impact of weighting tropospheric ties. The results indicate that strong weight provides the most benefit from using tropospheric ties. Nevertheless, systematic effects must be addressed to avoid degradation in the combined solution. It is important to note that one full set of local ties, i.e., both horizontal and vertical components, is necessary to use tropospheric ties since they cannot fulfill rank deficiencies in the NEQ system.

Description: Die vier geodätischen Raumverfahren VLBI (Very Long Baseline Interferometry), GNSS (Global Navigation Satellite System), SLR (Satellite Laser Ranging) und DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) liefern Beiträge zum besseren Verständnis des Erdsystems. Ihre Datensätze sind von zentraler Bedeutung für die Realisierung eines präzisen terrestrischen Referenzrahmens (ITRF). Da die einzelnen Messtechniken Stärken und Schwächen für die TRF-Bestimmung aufweisen, werden die Datensätze kombiniert mit dem Ziel, die Schwächen auszugleichen. Der aktuelle ITRF, der Internationale Terrestrische Referenzrahmen 2020 (ITRF2020), ist eine Lösung, die kombinierte Stationskoordinaten an den Kollokationsstationen unter Verwendung lokaler Verbindungsvektoren (local ties), d.h. den Abstandsvektoren zwischen den jeweiligen Referenzpunkten, und kombinierte EOP (Erdorientierungsparameter) liefert. Das globale geodätische Beobachtungssystem (GGOS) stellt an die Lage des Ursprungs des ITRF die wissenschaftlich begründete Genauigkeitsanforderung von 1 mm. Die ITRF2020-Genauigkeit erfüllt diese Vorgabe jedoch nicht ganz. Um dieses Ziel zu erreichen, sind daher innovative Ansätze zu entwickeln. Die geodätischen Raumverfahren VLBI und GNSS, die Signale im Mikrowellenfrequenzspektrum nutzen, liefern an den Kolokationsstationen Beobachtungsdaten unter den gleichen atmosphärischen Bedingungen. Die Verknüpfung atmosphärischer Parameter kann daher ebenfalls im Ausgleichungsprozess eingesetzt werden. Ähnlich wie die Stationskoordinaten können diese Parameter auch miteinander verknüpft, also kombiniert, werden. Die Verknüpfung troposphärischer Parameter wird als „tropospheric tie“ bezeichnet. Im Gegensatz zu den lokal ties, die mit Totalstationen oder anderen Messgeräten am Referenzpunkt des jeweiligen Sensors gemessen werden, können die troposphärischen ties nur mittels Modellrechnungen bestimmt werden. Dabei werden gegenwärtig zwei verschiedene Ansätze verfolgt. Zum einen erfolgt die Berechnung mittels eines analytischen Modells auf der Grundlage meteorologischer Daten, die aus unterschiedlichen Quellen stammen, beispielsweise meteorologische Sensoren am Messstandort, numerische Wettermodelle (NWM) oder empirische meteorologische Modelle. Zum anderen wird die Methode der Strahlverfolgung (ray tracing) durch ein vom NWM abgeleitetes Brechungsindexfeld eingesetzt. Diese nur aus Modellen berechneten troposphärischen ties weisen notwendigerweise eine begrenzte Genauigkeit auf. Für höhere Genauigkeiten müssen weitere systematische Effekte berücksichtigt werden, die zu Abweichungen zwischen den beobachteten troposphärischen Parametern und den troposphärischen ties führen. Um diese systematischen Effekte zu untersuchen, werden in dieser Arbeit troposphärische Parameter verglichen, die in GNSS- und VLBI-Analysen berechnet wurden. Die Ergebnisse zeigen, dass signifikante Abweichungen in der vertikalen Signallaufzeitverzögerung (zenith total delay, ZTD) durch instrumentelle Effekte des GNSS-Verfahrensverursacht werden, insbesondere durch Elevations-abhängige Laufzeitvariationen und Verwendung einer Abdeckvorrichtung „radom“. Abweichungen der horizontalen Gradienten werden hingegen nicht durch das Instrument beeinflusst, sondern durch Mehrwegeffekte, die sich insbesondere auf Beobachtungen bei geringen Elevationswinkeln auswirken. In dieser Studie wird bei VLBI-Messungen kein systematischer Effekt, der instrumentelle Ursachen hat, beobachtet. Der systematische Effekt in den troposphärischen Parametern, der auf das Instrument zurückzuführen ist, wird im Folgenden als „instrumental bias“ bezeichnet. Für die Überprüfung der Hypothese, dass der instrumental bias überwiegend durch instrumentelle Effekte der von GNSS-Beobachtungen abgeleiteten ZTD-Parametern verursacht ist, wurde ein GNSS-Kollokationsexperiment durchgeführt. Die Ergebnisse des Experiments bestätigen diese Hypothese. Des Weiteren zeigt sich, dass der instrumental bias der horizontalen Gradienten, die von GNSS-Beobachtungen bei niedrigen Elevationen abgeleitet wurden, auf multi-pathing zurückzuführen ist. Um den instrumental bias in den ZTD-Parametern zu bestimmen, wurde ein weiteres GNSS-Kollokationsexperiment realisiert. Hierbei wurden Unterschiede in der Phasenzentrumsposition der verschiedenen Antennentypen mittels eines höhenverstellbaren Antennenmasts bis auf wenige Millimeter ausgeglichen. Während der Messung konnte die Position der Antennenreferenzpunkte erfolgreich innerhalb eines Bereichs von 2 mm gehalten werden. Die verbleibenden Abweichungen in den abgeleiteten troposphärischen Parametern sind daher nicht auf troposphärische Effekte sondern lediglich auf instrumentelle Ursachen zurückzuführen. Möglichkeiten und Grenzen der tropospheric ties werden in dieser Studie durch eine Kombination von VLBI- und GNSS-Beobachtungsdaten auf Normalgleichungsebene (NEQ) untersucht. Die Verwendung von tropospheric ties zeigt signifikante Effekte auf die Kombination von VLBI bzw. GNSS. Eine VLBI-Intratechnikkombination zweier Teleskope an der Kollokationsstation Hobart, Australien, während der CONT14-Messkampagne führt zu einer Genauigkeitssteigerung bezüglich der Stationskoordinaten und der troposphärischen Parameter. Die Untersuchung der tropospheric ties zeigt, dass sie eine Alternative zu den local ties darstellen, z.B. wenn diese fehlerbehaftet sind, insbesondere in der vertikalen Komponente. Die Ergebnisse zeigen, dass VLBI den größten Nutzen aus der Kombination von troposphärischen Parametern mit tropospheric ties zieht, sowohl bei den Stationskoordinaten als auch bei den troposphärischen Parametern. Es wird untersucht, welche zeitliche Auflösung für die Anwendung der tropospheric ties geeignet ist. Die Ergebnisse zeigen ähnliche Resultate für alle Szenarien, sowohl für Stationskoordinaten als auch für troposphärische Parameter. Zum ersten Mal wird eine Kombination von GNSS und VLBI unter Verwendung der tropospheric ties mit einer Korrektur des instrumental bias durchgeführt. Die Ergebnisse zeigen eine signifikante Verbesserung der Stationskoordinaten, insbesondere bei VLBI. Darüber hinaus wird durch die Anwendung der tropospheric ties mit der instrumental bias-Korrektur die Diskrepanz zwischen den local ties und den Ergebnissen aus den geodätischen Raumverfahren deutlich verringert. Bei den troposphärischen Parametern kann durch die Anwendung der instrumental bias-Korrektur jedoch keine Verbesserung nachgewiesen werden. Auch die Folgen der Gewichtung der tropospheric ties wird untersucht. Die Ergebnisse zeigen, dass sich eine hohe Gewichtung positiv auf die Verwendung der tropospheric ties auswirkt. Allerdings müssen systematische Effekte berücksichtigt werden, um eine Verschlechterung der kombinierten Lösung zu vermeiden. Es ist wichtig darauf hinzuweisen, dass für die Verwendung der tropospheric ties ein vollständiger Satz an local ties erforderlich ist, da die tropospheric ties nicht die Rangdefizite im NEQ-System ausgleichen können.

Description: BeiDou Navigation Satellite System (BDS), the Chinese component of Global Navigation Satellite Systems (GNSS), has come into operation and started to serve global users publicly since July 31st, 2020. BDS-3, i.e., the latest development of BDS, provides many services not only the traditional Position, Navigation and Timing (PNT) but also several featured ones such as Satellite-Based Augmentation Service (SBAS), Precision Point Positioning (PPP), Short Message Communication Service (SMCS) and Search And Rescue (SAR). Precise and accurate orbit and clock products are the perquisites of a GNSS to guarantee a high-quality service performance. BDS-3 is the first GNSS in which the Inter-Satellite-Link has been constellation-widely deployed. It has been preliminarily demonstrated that this new feature of BDS-3 improves the system’s survivability as well as its independence on the ground tracking. This study is devoted to the Precise Orbit Determination (POD) of BDS-3 with newly available ISL observations. The inherent incapability of ISL measurements of sensing the absolute variations of Right Ascension of the Ascending Nodes (RAANs) of satellite orbits hinders the autonomous orbit determination free from ground support. Different approaches to constrain the constellation rotation have been studied in the literature. On the other hand, orbit determination using only ISL observations can serve to evaluate the performance of the newly carried Inter-Satellite-Link payloads. Depending on the satellite, the post-fit RMS of ISL range observations is 4.2~10.5 cm. Eliminating the effects of constellation rotations, orbit precision based on ISL range observations is around 7.0, 4.6, and 3.5 cm in the along-track, cross-track, and radial direction, respectively. The clock observations of ISLs are used to synchronize the clocks of satellites within the constellation. The post-fit RMS of ISL clock observations ranges from ~2.9 cm to 10.0 cm, differing for satellites. For most satellites, similar precision of clock offsets as the IGS MGEX ACs’ products can be obtained by ISL measurements, with STDs around 0.15 ~ 0.20 ns. Hardware delays of Inter-Satellite-Links estimated from the range and clock observations both show very good temporal stability, with a monthly average STD of 0.13 and 0.08 ns, respectively. Harmonic signals taking the orbit motion as the fundamental frequency are found in both the range and clock residuals. Although it turns out those harmonic signals only affect the results marginally, a Fourier-like periodic function model is proposed to absorb them and has been proved effective. Several unresolved issues related to the POD of BDS-3 are investigated based on ground tracking data before studying the contributions of additional ISL observations. The effects of non-conservative perturbations from the Earth’s albedo and antenna thrust are significant and, therefore, need to be considered in the POD of BDS-3. The applicability of different empirical Solar Radiation Pressure (SRP) models and the necessity of an extra a-priori box-wing model are evaluated. Generally, the ECOM2 model shows superiority over the ECOM1 model as for BDS-3 satellites. And if the ECOM2 model is adopted,the additional a-priori box-wing model is unnecessary. In order to keep the backward compatibility of BDS-2, the strategy for integrated processing of BDS-2 and BDS-3, in which the legacy frequency combination B1I+B2I remains unchanged for BDS-2, is proposed and demonstrated. The contributions of incorporating ISL observations to the POD of BDS-3 are assessed comprehensively. First, the benefits of additional ISL range measurements are demonstrated in cases of different ground tracking networks. Secondly, the somehow unexpected improvement in the orbit precision brought by incorporating ISL clock observations is displayed. Furthermore, integratedly processing the ISL derived range, ISL derived clock, and L-band ground tracking observations reduces the orbit DBD by ~39% and 42% in the along-track and radial directions, respectively, compared to using only ground-tracking data. Last but not least, the contributions of ISL measurements to the estimation of geodetic parameters are proved, especially for the geocenter coordinates. Strong correlations between empirical SRP parameters and the geocenter Z-component, which plague the community for a long time, are significantly reduced by adding ISL observations. The results are very promising not just in terms of establishing and maintaining a national BDS-based terrestrial reference frame but also improving the potential contribution of BDS via the IGS community to the International Terrestrial Reference Frame (ITRF).

Description: Das BeiDou Navigation Satellite System (BDS), die chinesische Komponente von Global Navigation Satellite Systems (GNSS), ist seit dem 31. Juli 2020 in Betrieb und dient weltweit Benutzern öffentlich. BDS-3, dh die neueste Entwicklung von BDS, bietet viele Dienste, nicht nur die traditionelle Position, Navigation und Zeitmessung (PNT), sondern auch mehrere Funktionen wie der satellitengestützte Augmentation Service (SBAS), Precision Point Positioning (PPP), Short Message Communication Service (SMCS) und Search And Rescue (SAR). Präzise und genaue Orbit- und Clock-Produkte sind die Voraussetzungen für ein GNSS, um eine qualitativ hochwertige Serviceleistung zu gewährleisten. BDS-3 ist das erste GNSS, bei dem der Inter-Satellite-Link konstellationsweit eingesetzt wurde. Es wurde vorläufig gezeigt, dass diese neue Funktion von BDS-3 die Überlebensfähigkeit des Systems sowie seine Unabhängigkeit von der Bodenverfolgung verbessert. Diese Studie widmet sich der Precise Orbit Determination (POD) von BDS-3 mit neu verfügbaren ISL-Beobachtungen. Die inhärente Unfähigkeit von ISL-Messungen, die absoluten Variationen der Right Ascension of the Ascending Nodes (RAANs) von Satellitenumlaufbahnen zu erfassen, behindert die autonome Umlaufbahnbestimmung ohne Bodenunterstützung. In der Literatur wurden verschiedene Ansätze untersucht, um die Konstellationsrotation einzuschränken. Andererseits kann die Bestimmung der Umlaufbahn, die nur ISL-Beobachtungen verwendet, dazu dienen, die Leistung der neu beförderten InterSatellite-Link-Nutzlasten zu bewerten. Abhängig vom Satelliten beträgt der Post-Fit-RMS der ISLBereichsbeobachtungen 4,2 bis 10,5 cm. Unter Eliminierung der Auswirkungen von Konstellationsrotationen beträgt die Orbit-Präzision basierend auf ISL-Entfernungsbeobachtungen etwa 7,0, 4,6 bzw. 3,5 cm in Längs-, Quer- und Radialrichtung. Die Uhrenbeobachtungen von ISLs werden verwendet, um die Uhren von Satelliten innerhalb der Konstellation zu synchronisieren. Der Post-Fit-RMS von ISL-Uhrbeobachtungen reicht von ~2,9 cm bis 10,0 cm, unterschiedlich für Satelliten. Bei den meisten Satelliten kann durch ISL-Messungen eine ähnliche Genauigkeit der Taktverschiebungen wie bei den Produkten der IGS MGEX ACs mit STDs von etwa 0,15 bis 0,20 ns erreicht werden. Hardwareverzögerungen von Inter-Satellite-Links, die aus den Entfernungs- und Taktbeobachtungen geschätzt wurden, zeigen beide eine sehr gute zeitliche Stabilität mit einer monatlichen durchschnittlichen STD von 0,13 bzw. 0,08 ns. Harmonische Signale, die die Bahnbewegung als Grundfrequenz nehmen, werden sowohl in den Entfernungs- als auch in den Taktresten gefunden. Obwohl sich herausstellt, dass diese harmonischen Signale die Ergebnisse nur marginal beeinflussen, wird ein Fourier-ähnliches periodisches Funktionsmodell vorgeschlagen, um sie zu absorbieren und sich als effektiv erwiesen hat. Mehrere ungelöste Probleme im Zusammenhang mit dem POD von BDS-3 werden auf der Grundlage von Bodenverfolgungsdaten untersucht, bevor die Beiträge zusätzlicher ISL-Beobachtungen untersuchtwerden. Die Auswirkungen nicht-konservativer Störungen durch die Albedo der Erde und den Antennenschub sind signifikant und müssen daher im POD von BDS-3 berücksichtigt werden. Die Anwendbarkeit verschiedener empirischer Solar Radiation Pressure (SRP)-Modelle und die Notwendigkeit eines zusätzlichen a-priori-Box-Wing-Modells werden evaluiert. Im Allgemeinen zeigt das ECOM2- Modell eine Überlegenheit gegenüber dem ECOM1-Modell für BDS-3-Satelliten. Und wenn das ECOM2- Modell übernommen wird, ist das zusätzliche A-priori-Box-Wing-Modell überflüssig. Um die Abwärtskompatibilität von BDS-2 zu erhalten, wird die Strategie zur integrierten Verarbeitung von BDS- 2 und BDS-3 vorgeschlagen und demonstriert, bei der die Legacy-Frequenzkombination B1I+B2I für BDS-2 unverändert bleibt. Die Beiträge der Einbeziehung von ISL-Beobachtungen in den POD von BDS-3 werden umfassend bewertet. Zunächst werden die Vorteile zusätzlicher ISL-Entfernungsmessungen bei unterschiedlichen Bodenverfolgungsnetzwerken demonstriert. Zweitens wird die irgendwie unerwartete Verbesserung der Bahngenauigkeit durch die Einbeziehung von ISL-Uhrenbeobachtungen angezeigt. Darüber hinaus reduziert die integrierte Verarbeitung der ISL-abgeleiteten Entfernung, des ISL-abgeleiteten Takts und der L-Band-Bodenverfolgungsbeobachtungen die Bahn-DBD um ~39 % bzw . Nicht zuletzt werden die Beiträge von ISL-Messungen zur Schätzung geodätischer Parameter, insbesondere für die Geozentrumskoordinaten, nachgewiesen. Starke Korrelationen zwischen empirischen SRP-Parametern und der Geozentrum-Z-Komponente, die die Community schon lange plagen, werden durch das Hinzufügen von ISL-Beobachtungen deutlich reduziert. Die Ergebnisse sind nicht nur im Hinblick auf die Einrichtung und Aufrechterhaltung eines nationalen BDS-basierten terrestrischen Referenzrahmens sehr vielversprechend, sondern auch hinsichtlich der Verbesserung des potenziellen Beitrags von BDS über die IGS-Community zum International Terrestrial Reference Frame (ITRF).

Description: The recent deliverable describes the development and the characteristics of the European Fluid Atlas (EFA) created in the frame of the REFLECT project by University of Miskolc. In the Atlas, formerly existing and newly measured data of geothermal fluids are visualised. Fluid data were collected from 21 European countries. The layers provide point feature information presented on a base map, including geography, geology, and depth range, as well as physical, chemical and microbial properties of fluids. Data of wells, rocks and reservoirs are also available. The focus is on fluids used for electricity generation (〉 100 °C), but data from heat projects are also included. A free and open-source cross-platform is used for the visualisation, in which the geographic information system provides the environment to view, edit and analyse geospatial data. The interface includes query and filtering tools to explore the database with a map-based visualization. The query results can be downloaded as an excel worksheet. By selecting the entire dataset, the downloaded report contains all the data published on EFA.

Description: Deliverable D2.4 reports on the activities performed within Task 2.4 “Thermophysical properties of geothermal fluids” until the end of month 36 of the REFLECT project. The task breaks down into three subtasks of different scope: Task 2.4.1 - In situ measurements of fluid thermophysical properties, Task 2.4.2 - Thermoelectrical properties, and Task 2.4.3 - Modelling of density and heat capacity. Overall, a better understanding of the thermophysical properties of highly saline geothermal fluids was obtained by a combination of analytical data evaluation, improvement of measurement devices, laboratory measurements and numerical modelling.

Description: This report summarises the webinars organised in the REFLECT project between 2021 and 2022, in the framework of the WP6 Dissemination and exploitation, Task 6.2 – Ensure transferability and exploitation of project results. The Task 6.2 planned to inform the stakeholders identified in the matrix developed under Task 6.1 about the project activities and main outcomes. For this purpose, periodic webinars have been organised between 2021 and 2022 presenting these results and information.

Description: This report presents the stakeholder workshops organised in the REFLECT project, in the framework of the WP6 Dissemination and exploitation, Task 6.2 – Ensure transferability and exploitation of project results. The Task 6.2 planned to inform the stakeholders identified in the matrix developed under Task 6.1 about the project activities and main outcomes. For this purpose, two physical stakeholder workshops were organised during the project. The first workshop, at the start of the project, was dedicated to a first communication of the project’s objectives and expected outcomes. It also had the aim to receive feedback from geothermal operators on their most significant operational problems related to geothermal fluid properties. This first workshop was, therefore, limited to the Advisory Board members in order to build on their specific experience. The second stakeholder workshop presented the project’s results most relevant to geothermal operators or service companies/consultants. The objective of the second stakeholder workshop was to share projects results with a broad group of stakeholders. Therefore, it was widely promoted and the registration was open to all and free of charge. Both workshops received positive feedback from stakeholders and project partners.

Description: Global growth of industry and population leads to increasing demand of industrial and consumer goods. This necessitates an increase in mining activities and resource extraction. Resulting mine waste, and tailings serve as a repository for unused overburden and for the accumulation of processed waste-products. It is typical for so-called secondary iron minerals (SIMs) to be formed during the weathering of these materials under different pH-value conditions. Acid mine drainage (AMD) can result from rainwater infiltration and chemical processes within the deposited mass. Therefore, mine tailings must be spatially separated from their surroundings and monitored. The emergence of remote sensing methods provides new opportunities to survey large areas. In this work a remote sensing approach was used to discriminate SIMs from surrounding material and minerals and subsequently classify different SIMs on the surface. This allows to reconstruct (/comprehend the former) the acidic environments that prevailed during the formation of these minerals and gives indication of the occurrence of AMD. Various SIMs have pH-values ranging from strongly acidic (〈1.5, i.e., Schwertmannite and Copiapite) to neutral (〉7, i.e., Hematite). Classifying these SIMs, leads to the identification of contaminated areas. This method was developed based on a laboratory dataset with different minerals and vegetation samples. The datasets were originally acquired with hyperspectral HySpex cameras in the laboratory and were resampled to WorldView-3 (WV3) and Sentinel-2 (S2) band characteristics for analysis. A combination of different filter methods made pixel-based separation of SIMs possible. The results were subsequently classified using a RF-model to distinguish between different SIMs. In this training dataset, the RF model achieved an overall accuracy of 94.44% for the WV3 and S2 datasets (the area-adjusted overall accuracy was 93.45% and 93.62%, respectively). Subsequently, a second laboratory dataset with field samples was analysed using the same technique and the classification results were compared with XRD analyses of the samples. Satellite images from WV3 and S2 sensors were then analysed using this methodology. The results for the study area of volcanogenic massive sulphide deposits in the Republic of Cyprus, namely Skouriotissa and Apliki, were then compared. The results for the Skouriotissa mine region showed a potential area of 17.22 to 45.58 ha of strongly acidic environment (by classification of Jarosite, pH~2.4) and 8.86 to 26 ha of moderately acidic environment/ contamination (by classification of Goethite/Limonite, pH~5) based on the WV3 satellite image. 27.32 to 87.04 ha and 6.12 to 38.24 ha for the S2 image, respectively.

Description: Das Wachstum von Industrie und Bevölkerungszahl weltweit sowie technologische Fortschritte und Entwicklungen führen zu einer steigenden Nachfrage von Industrie- und Konsumgütern. Als Folge entstehen eine erhöhte Rohstoffnachfrage und ein Ausbau der Ressourcengewinnung sowie des Bergbaus. Abfallprodukte des Bergbaus und nicht genutztes Material (Abraum) werden meist in oder um den Abbaustandort aufgeschüttet. Diese sind natürlichen Degradationsprozessen ausgesetzt, bei denen saure Abwässer entstehen können. Dies geschieht durch die Verwitterung des Pyrit Minerals infolge der Infiltration von Regenwasser durch das Material. In unterschiedlichen pH-Wertumgebungen bilden sich unterschiedliche Minerale aus. Typisch sind die sogenannten sekundären Eisenminerale (SIMs – secondary iron minerals). Ein Auftreten dieser kann daher zu einer pH-Wert Abschätzung genutzt werden und mögliche saure Grubenwässer aufzeigen. Fernerkundungsmethoden bieten die Möglichkeit große Areale oberflächlich zu erfassen und abzubilden, was zu einer weitreichenden Überwachung genutzt werden kann. In dieser Arbeit wurde eine Methode auf Grundlage von multispektralen Fernerkundungsdaten (Satellitenbilder von WorldView-3 und Sentinel-2) entwickelt, welche sekundäre Eisenminerale identifiziert und klassifiziert. Die Identifikation wurde durch den Einsatz von Masken erreicht. So fand eine Unterscheidung zwischen Pixeln statt, die und die keine typische spektrale Signale von SIMs aufweisen. Die Klassifikation wurde mit Hilfe eines RF-Modells durchgeführt. Dieses wurde anhand synthetischer Labordatensätze entwickelt und validiert. Im Trainingsdatensatz erreichte das RF-Modell eine Gesamtgenauigkeit von 94,44 % für die WorldView-3 und Sentinel-2 Datensätze. Es wurden drei Klassen mit verschiedenen pH-Wert-Identifikationen unterschieden: Hämatit (pH〉7), Goethit/ Limonit (pH~5) und Jarosit (pH~2.4). Die Methodik wurde anschließend auf Satellitenbilder aus der Republik Zypern angewendet. Dabei standen die Minengebiete Skouriotissa und Apliki im Fokus, welche zu den vulkanogenen Massivsulfid-Lagerstätten (VMS-type) zählen. Die Ergebnisse für das Skouriotissa-Minengebiet ergaben auf der Grundlage des WV3-Satellitenbildes eine potenzielle Fläche von 17,22 bis 45,58 ha in stark saurem Milieu (Jarosit) und 8,86 bis 26 ha in mäßig saurem Milieu (Goethit/ Limonit) bzw. 27,32 bis 87,04 ha und 6,12 bis 38,24 ha für das Sentinel-2 Satellitenbild.

Description: The evaluation of the effect of organic compounds and microorganisms in formation and precipitation of colloids using artificial brines was performed by TNO using selected organic compounds based on the analysis of sampled fluids corresponding to the information gathered on the sites by GFZ. The same was done with biofilms prepared with microorganisms (Thermaerobacter sp., Penicilium citrinum) isolated from geothermal stations by UNINE. All carboxylic acids tested had an inhibiting effect on the precipitation of calcium carbonate. The biofilm components seem to develop intense interaction with the ions, nuclei and/or crystals formed during the executed experiments. In the presence of biofilms, the transformation of the intrinsically formed vaterite morphology to equilibrium calcite morphologies is delayed or hindered and scaling was inhibited.

Description: This Technical Report presents data from a solaroptical spectral investigation in the area of the Rammelsberg non-ferrous metal mine in the Harz Mountains near the city of Goslar. The investigation refers to the local communion stone quarry (“Kommunionssteinbruch”) above the former mining area. As this is a nature conservation zone, all measurements were carried out in-situ without any physical sampling action. The field measurements were carried out in June 2019 in cooperation with Bergbau Goslar GmbH and the German Research Centre for Geosciences (GFZ). The data were collected within the research project ReMon (Remote Monitoring of Tailings Using Satellites and Drones, https://www.gfzpotsdam. de/en/section/remote-sensing-and-geoinformatics/projects/remon/) which aims at developing a prototypical monitoring system for mine tailings by using different sensors scaling from satellite- to drone-based. The data were analysed in the unpublished B.Sc. thesis of Constantin Hildebrand (Hildebrand, 2019). Sixteen different surface materials were determined and examined on-site. Point and imaging hyperspectral data were acquired (with the spectroradiometer PSR+ 3500 operating in the range of 350 - 2500 nm and with the Cubert FireflEYEUHD-185 hyperspectral camera with a range of 450 - 950 nm, respectively), both data sets are presented as spectral libraries. Chemical analyses of the samples were performed by using Laser-Induced Breakdown Spectroscopy (LIBS). LIBS data were collected using a handheld LIBS analyzer, the SciAps Z-300. In this report the different in-situ measurements are presented for each of the sixteen samples. Detailed information about the analysed material, the area of spectral sampling and geochemical analyses are explained in this report and can also be found in the additional Excel® sheet provided with the data.

Description: ???

Description: This document is a collection of the REFLECT factsheets produced for promoting the project results.

Description: This deliverable summarizes the activities related to the development of predictive models to simulate the impact of fluid flow hydrodynamics and chemical composition uncertainties on the production behavior of geothermal assets. Specifically, in this report, the mineral precipitation behavior of the geothermal fluid was studied as both uncertainties in the fluid composition and the interaction between the fluid flow hydrodynamics and mineral precipitation can impact the deposition of the scaling. A workflow was developed to couple a multiphase flow solver to thermodynamics libraries and models which are used to simulate the precipitation amount and kinetics of different geothermal minerals. This coupled workflow will enable a better estimation of the location and amount of precipitated minerals in different location of a geothermal system. A detailed roughness model was developed to simulate the impact of mineral deposition to the fluid flow. In addition, an uncertainty quantification workflow was combined with the modelling framework to estimate the uncertainty bounds of the scaling and precipitation resulted from uncertainties in the fluid composition characterization and operational settings. The modelling and uncertainty quantification workflow was demonstrated on a barite precipitation case study in a heat exchanger. Initially, the impact of geo-chemical uncertainties (in fluid composition) on the mineral precipitation was assessed. Afterwards, the coupled fluid flow and precipitation model with the developed roughness model was tested. Finally, the coupled uncertainty quantification workflow with the coupled model was simulated to assess the impact of fluid composition uncertainties on mineral deposition. As an outcome of the simulation, the impact of uncertainties in the mineral deposition on reduction in the production rate and heat transfer (within the heat exchanger) was calculated. The developed framework is flexible and generic which can be applied to various production and operational challenges in geothermal assets. In the future, the workflow can be used to optimize the design and operation of geothermal assets considering various sources of uncertainties which is not only fluid composition but also operational conditions (link to D4.5 REFLECT), robust modelling of other geo-chemical and flow assurance challenges in geothermal sites or even developing geo-chemical risk maps for different sites within EU (link to WP3 REFLECT).

Description: This Deliverable reports results for the Tuzla Geothermal Field (TGF), which is located in the western part of Turkey. In this field, there are a total of four geothermal wells (three production wells and one reinjection wells). The TGF has a binary cycle geothermal power plant. The most pressing issue in the TGF is silica-based scale. This study lists the results from analysis of physical and chemical properties of the geothermal fluid. It also includes the mineral analysis from scale samples of some of the wells of the geothermal field. Those results have been utilised in geothermometry to estimate temperatures within the TGF. Finally, mineral precipitation is investigated with a focus on silica-based scaling.

Description: The FOSA (FOgo Seismic Array) project has been carried out from October 2015 to December 2016 to investigate the seismicity of Fogo volcano after its eruption in 2014/2015. Fogo is the only volcano of the Cape Verde archipelago with reported historic eruptions. The eruptions occur frequently with an interval of about 20 years. However, the structure and extent of the related volcanic plumbing system are not well understood. The focus of the FOSA project was on the detection of ongoing magmatic activity and information about the plumbing system, using seismic array techniques. The array of the FOSA study was operated from October 2015 to December 2016, close to the village Achada Furna. From January 2016 we complemented the network with three additional broadband stations for an improved event detection and localization.

Description: The KISS network was installed in the frame of the “Klyuchevskoy Investigation - Seismic Structure of an extraordinary volcanic system” project and recorded data between summer 2015 and summer 2016 in one of the world’s largest clusters of subduction volcanoes - the Klyuchevskoy volcanic group (KVG). It is located in eastern Russia at the northern end of the Kuril-Kamchatka subduction zone close to its intersection with the Aleutian arc and the north-western termination of Hawaii-Emperor seamount chain. Additional to the 4700m high Mount Klyuchevskoy the KVG contains 12 other volcanoes that have together erupted about 1 cubic meter rock per second averaged over the past 10,000 years. Among those Klyuchevskoy, Bezymianny and Tolbachik were the most active ones during the last decades with eruptions styles ranging from explosive to Hawaiian-type. The KISS experiment is designed to investigate the volcanic and seismic processes and its structural setting in the KVG. The network covers a circular region of about 80km diameter with some linear extensions. It includes data from 77 temporary seismic stations with broadband and short period sensors that were installed on concrete plates in about 60cm deep holes. Due to the local conditions the stations were battery powered and could not be serviced during the experiment. GPS reception of the digitizers was not continuous at all stations due to thick snow cover and vegetation. Waveform data are available from the GEOFON data centre, under network code X9, and are embargoed until end of 2019.

Description: This report describes the KTB Borehole Measurements Data of the German Continental Deep Drilling Program (Kontinentales Tiefbohrprogramm der Bundesrepublik Deutschland), operated by the GFZ German Research Centre for Geosciences. Extensive borehole measurements were performed during the active drilling phase of the KTB pilot and main hole (1989-1994). This report provides the full description of the logging data. Please read it thoroughly to avoid inappropriate or wrong use of the data. The terms borehole measurements, downhole logging, and logging are used synonymously here. The KTB logging data files contain the final processed versions of the geoscientific borehole logging data from logs in the two KTB boreholes: Boreholes Geographic Coordinates (WGS84) KTB-Oberpfalz VB (KTB Vorbohrung/Pilot Hole or KTB-VB) 49.8153 N, 12.118 E KTB-Oberpfalz HB (KTB Hauptbohrung/Main Hole or KTB-HB) 49.8152 N, 12.1205 E

Description: The 3D geomechanical-numerical modelling of the in-situ stress state aims at a continuous description of the stress state in a subsurface volume. It requires observed stress information within the model volume that are used as a reference. Once the modelled stress state is in agreement with the observed reference stress data the model is assumed to provide the continuous stress state in its entire volume. The modelled stress state is fitted to the reference stress data records by adaptation of the displacement boundary conditions. This process is herein referred to as calibration. Depending on the amount of available stress data records and the complexity of the model the manual calibration is a lengthy process of trial-and-error modelling and analysis until best-fit boundary conditions are found. The Fast Automatic Stress Tensor Calibration (FAST Calibration) is a Python function that facilitates and speeds up this calibration process. By using a linear regression it requires only three model scenarios with different boundary conditions. The stress states from the three model scenarios at the locations of the reference stress data records are extracted. The differences between the modelled and observed stress states are used for a linear regression that allows to compute the displacement boundary conditions required for the best-fit modelled stress state. If more than one reference stress state is provided, the influence of the individual observed stress data records on the best-fit boundary conditions can be weighted. The script files are provided for download at: http://github.com/MorZieg/PyFAST_Calibration

Description: The Earth’s upper atmosphere – a part of it, the ionosphere- is a dynamic partly ionized region with temporal and spatial variations under different phases of solar activity. The ionosphere being a dispersive medium causes signal strength fluctuation, propagation delay, signal attenuation, and signal degradation. These have constituted significant threats to both communication and navigation systems operating in microwave band which is due to the presence of high electron density and its irregularities. The key parameter of the ionosphere which is closely related to most of these delay effects on radio signals is the electron density and density gradients, in particular - its vertical integral, the Total Electron Content (TEC) which can be estimated from the Global Positioning System (GPS) data. The estimated TEC profiles, and TEC perturbation are studied to gain insights into the occurrence of irregular structures in the ionosphere and their distribution. One of the ionospheric irregularities located within the F region, and E region top side are Traveling ionospheric disturbances (TIDs). TIDs are propagating perturbations in the ionospheric electron density as a consequence of Atmospheric Gravity Waves (AGWs) passage. The AGWs originate in the troposphere or stratosphere, and exhibit neutral wind perturbations propagating to the F region heights (i.e. ionospheric heights), where the neutral wind perturbations interact with the plasma via collisions, carrying it along the magnetic field lines (i.e. ion-neutral collision). This entire process in the ionosphere is manifested as oscillations of the ionospheric electron density, resulting in a TID. However, TIDs vary in scale sizes ranging within a few hundred kilometers (km) to over one thousand km, and based on this, they are categorized as either medium-scale TIDs (MSTIDs) or large scale TIDs (LSTIDs). In this thesis, we focus only on MSTIDs as one of the major and frequent ionospheric irregularity phenomena which may degrade positioning systems and could cause a delay in GPS signal transmission between a satellite and the GPS receiver. Multiple studies of ionospheric irregularities with the main focus on MSTIDs over different regions and continents around the world have been carried out, but studies of MSTIDs over the African region have neither been carried out nor reported probably due to lack of GPS data set, and the question of what drives its occurrence in the region which is not yet documented. The objective of this thesis is to study and describe for the first time the occurrence of MSTIDs and its characteristics over the African region under quiet geomagnetic condition (Kp ≤ 3) during the years 2008 – 2016. In addition, this thesis presents novel results of the time series of MSTIDs percentage occurrence rate (POR) during daytime and nighttime, and seasonal occurrence. Ionneutral coupling processes like the connection between AGW and MSTIDs are also discussed in the study. Observational TEC data used in this thesis are obtained from ground-based GPS networks within the African region and nearby stations. Additionally, temperature data from COSMIC radio occultation and SABER satellite observations for some case studies were used to validate AGWs passage as a driving source of MSTIDs, especially during the daytime. Consequently, regional MSTIDs distribution maps have been generated to capture the latitudinal, seasonal, and local time extent of the MSTID occurrence. Investigation of regional ionospheric irregularities over Africa (IRIA) gives a novel result of a climatological view of MSTIDs over Northern and Southern hemispheres in the African region.

Description: In this interim report, the studies on geothermal fluids carried out in Turkey, France and Iceland geothermal fields are explained.

Description: The ionosphere is a complex and highly variable physical system with the F-layer, which occupies at the highest altitude, contains the greatest concentration of free electrons. Under the extreme circumstance of the ionosphere such as in the periods of high solar activity or magnetic storms or simply in the equinoctial months each year, this layer is very often disturbed. During the disturbances, the small-scale irregularities develop and disperse microwave radio signals, and thus generate rapid fluctuations in the amplitude and phase of satellite signals. This phenomenon causes the ionosphere to be scintillated and is called ionospheric scintillation. The impacts of scintillation cannot be mitigated by the multi-frequency technique that is very effective when dealing with ionospheric delay. Consequently, ionospheric scintillation is one of the most significant threats for space geodetic techniques, especially for stations operating in the polar regions or areas near the equator. To study ionospheric scintillation, alternative methods have been proposed including the method of using high-rate receivers to directly output S4 index over Vietnam region and the method of using standard GNSS dual-frequency to calculate ROTI index on a global scale. Main results of this thesis are the temporal variations of total number electron (TEC) in Southeast Asia for eleven consecutive years and the appearance characteristics of scintillation over this area as well as globally during solar cycle 24 (SC24). For space geodesy, electromagnetic waves are most vulnerable in the equatorial ionization anomaly (EIA) as this region has many potential risks of errors for satellite signals. The research area (Southeast Asia) is also located entirely within the EIA. In this thesis, the temporal - latitudinal VTEC maps have been established to study the modifications of EIA’s structure. Thereby, the featured occurrence of EIA crests in Southeast Asia is revealed. Also, the global morphology of anomaly crests averaged over 11-year period shows the worldwide distribution of EIA crests during SC24. Throughout the thesis, the high consistency between the state of the ionosphere and the activity status of the Sun is evidenced by high correlations between VTEC and solar indices. In which, the radio flux index (F10.7 cm) is proved to be more agreeable to the VTEC development than the sunspot number (SSN). The behaviour of the ionosphere during intense magnetic storms is also investigated. The results show that the structure of EIA is often highly volatile during these severe ionospheric conditions.

Description: Die Ionosphäre ist ein komplexes und hochvariables physikalisches System, wobei die am höchsten gelegene F-Schicht die höchste Konzentration an freien Elektronen enthält. Unter den extremen Bedingungen der Ionosphäre, wie beispielsweise in den Perioden hoher Sonnenaktivität oder magnetischer Stürme oder einfach in den Äquinoktialmonaten eines jeden Jahres, ist diese Schicht der Ionosphäre häufig gestört. Während der Störungen propagieren und zerstreuen die kleinräumigen Unregelmäßigkeiten Mikrowellen-Radiosignale und erzeugen so schnelle Schwankungen in der Amplitude und in der Phase der Satellitensignale. Dieses Phänomen führt zu einer Szintillation der Ionosphäre und wird oft als ionosphärische Szintillation bezeichnet. Im Prinzip können die Auswirkungen der Szintillation nicht durch die Mehrfrequenztechnik verringert werden, die bei der Behandlung der ionosphärischen Verzögerung sehr effektiv ist. Aus diesen Gründen ist die ionosphärische Szintillation eine der größten Herausforderungen für geodätische Weltraumtechniken, insbesondere für Messstationen, die in den Polarregionen oder in äquatornahen Gebieten einschließlich Südostasiens arbeiten. Zur Untersuchung der ionosphärischen Szintillation wurden alternative Methoden vorgeschlagen, darunter die Methode der Verwendung von Hochfrequenz-Empfängern zur direkten Ausgabe des S4-Index über der Region Vietnam und die Methode der Verwendung der standardmäßigen GNSS Zweifrequenzmessungen zur Berechnung des ROTI-Index zur Untersuchung ionosphärischer Unregelmäßigkeiten im globalen Maßstab. Die Hauptergebnisse der Arbeit beinhalten die zeitlichen Variationen des Gesamtelektroneninhalts (total electron content, TEC) in Südostasien für elf aufeinander folgende Jahre und die Erscheinungsmerkmale der Szintillation während des 24. Sonnenzyklus (SC24) sowohl über diesem Gebiet als auch auf globaler Ebene. Für die Weltraumgeodäsie sind elektromagnetische Wellen in der äquatorialen Anomalie der Ionosphäre (equatorial ionization anomaly, EIA) am anfälligsten, da diese Region viele potenzielle Fehlerrisiken für Satellitensignale aufweist, welche bei der Übertragung aus dem Weltraum die Ionosphäre durchqueren. Das Forschungsgebiet (Südostasien) befindet sich ebenfalls vollständig innerhalb der EIA. In dieser Arbeit wurden die zeit und breitenabhängigen Karten des VTEC erstellt, um die Veränderungen der Struktur der EIA zu untersuchen. Dabei wird das charakteristische Vorkommen von Kämmen der EIA-Anomalie in Südostasien offen gelegt. Außerdem zeigt die globale Morphologie der Anomalie-Kämme, gemittelt über einen Zeitraum von elf Jahren, die weltweite Verteilung der EIA-Kämme während des SC24. Der starke Zusammenhang zwischen dem Zustand der Ionosphäre und dem Aktivitätszustand der Sonne wird durch hohe Korrelationen zwischen dem VTEC und den Sonnenindizes einschließlich der Sonnenfleckenzahl (sunspot number, SSN) und dem Radioflussindex F10,7 cm belegt. Auch das Verhalten der Ionosphäre während intensiver magnetischer Stürme wird untersucht. Die Ergebnisse zeigen, dass die Struktur der EIA unter diesen extremen ionosphärischen Bedingungen häufig sehr volatil ist.

Description: The Earth is rotating around its rotation axis in an irregular manner. The Earth rotation axis and its orientation in space vary with respect to the reference system (both the terrestrial and the celestial) due to the wide range of processes that contribute to the rotation excitation. Therefore, the study of the Earth rotation can provide essential information concerning the Earth system. Spaceborne geodetic sensors can determine Earth orientation parameters (EOP), which fully describe Earth’s behaviour in space. The EOP are needed for several fields and applications such as fundamental astronomical and geodetic reference systems, precise satellite orbit determination, space navigation, and disaster prevention.\\ Over the past three decades, climate change has caused undesirable alterations in living organisms, human activities, and socio-economic aspects. Climate change is fluctuating and alters weather patterns such as precipitation patterns and sea and ocean levels. It also threatens the biodiversity of ecosystems, food security, and human health, and exacerbates natural disasters. The intensity and frequency of natural hazards are increasing with erratic distribution due to changes in the climate. Also, the level of vulnerability and zonation of risk are changed. Analysis of natural hazards, such as atmospheric and hydrological events, can help improve crisis management. Therefore, satellite observation data and simulated data derived from different atmospheric models are needed in order to model different types of hazards and risks, which can help early warning and prediction systems. Even though continuous sensor measurements and archive data (historical data/climate) are used for weather forecasting in developed countries, deadly flooding happened close to Stuttgart in southern Germany in May 2016, which might be avoided by a precise weather warning system. Therefore, real-time space geodetic technique data estimation is necessary to use as input data in weather prediction models. For the analysis of space geodetic techniques in (near) real-time, predictions of the EOP are required. EOP are made available by the International Earth Rotation and Reference Systems Service (IERS) Rapid Service Prediction Centre at USNO, Washington D.C., with a delay of hours to days. Accordingly, in the past, several methods were developed and applied for the EOP prediction. However, the accuracy of EOP prediction is still unsatisfactory, even for prediction of just a few days in the future.\\ To improve the EOP prediction accuracy, this study investigates the consistency between Earth rotation’s theories and observations. Moreover, the potentials of different geophysical phenomena are examined to better understand the interaction of different processes that affect the Earth rotation excitation with the time. Most of the Earth’s rotation theories and solutions are based on the location of the Earth’s principal axes of inertia (PAI). That location is defined by the second-degree Stokes coefficients of the geopotential, which are accurately observed by the Gravity Recovery and Climate Experiment (GRACE) and satellite laser ranging (SLR). In this study, the evolution of the Earth’s axes of inertia is analyzed for the first time. The presented results are remarkable, as the inertia axes do not move around a mean position fixed to a given terrestrial reference frame in the study period, but drift away from their initial location in a non-negligible manner.\\ Moreover, this study proposes a novel hybrid approach to predict EOP. There is a well-introduced stochastic method called copula-based analysis, and I combined it with singular spectrum analysis (SSA) for EOP prediction. I analyzed the potential of copula-based methods for predicting Earth rotation parameters that are derived from the combination of different satellite geodetic sensors and from other geophysical parameters like effective angular momentums. The copula is a statistical method that exploits linear and non-linear relationships between two or more variables by fitting a theoretical copula function into an empirical bivariate or multivariate distribution function. I introduced a hybrid prediction method that can be applied to other geophysical parameters is introduced in this thesis.\\ In this study, the interconnection between the celestial pole motion (CPM) and geomagnetic field (GMF) is investigated to improve the current CPM prediction methods. During the last decade, several investigations have been conducted in order to discuss a possible interconnection of polar motion and geomagnetic jerks, which are rapid changes in GMF secular variations. However, less attention has been paid to the impact of the GMF changes on the CPM, e.g., the interrelation of the geomagnetic jerks, geomagnetic dipole moment, geomagnetic field elements, and CPM variations. In this study, I use the CPM time series obtained from very long baseline interferometry (VLBI) observations and the latest GMF data to explore the correlation between CPM and the GMF. Our preliminary results revealed some impressive common features in the CPM and GMF variations, which show the potential to improve our understanding of the GMF’s contribution to the Earth’s rotation. All in all, the results mathematically illustrate the coherency between the GMF parameters and CPM, which helps improve EOP products.

Description: Die Erde dreht sich um ihre Rotationsachse auf unregelmäßige Art und Weise. Die Erdrotationsachse und ihre Orientierung im Raum variieren in Bezug auf das Referenzsystem (sowohl im terrestrischen wie auch im zälestischen System) aufgrund des breiten Spektrums von Prozessen, die zur Rotationsanregung beitragen. Daher kann die Untersuchung der Erdrotation wesentliche Informationen über das Erdsystem liefern. Weltraumgestützte geodätische Sensoren liefern Informationen über erdgebundene Orientierungsparameter (EOP), die das Verhalten der Erde im Weltraum vollständig beschreiben. EOP werden für verschiedene Bereiche und Anwendungen, wie beispielsweise für grundlegende astronomische und geodätische Referenzsysteme, benötigt. Des Weiteren sind sie auch für die präzise Bestimmung von Satellitenorbits und die weltraumgestützten Navigation, bis hin zu Anwendungen im Katastrophenschutz von Bedeutung.\\ In den letzten drei Jahrzehnten zeigen sich bereits die negativen Auswirkungen des Klimawandels auf Biosphäre, menschliche Aktivitäten und sozioökonomische Aspekte. Der Klimawandel unterliegt Fluktuationen und verändert die Wettermuster, wie z.B. die Niederschlagsverteilung, sowie Meeres- und Ozeanspiegel. Er bedroht aber auch die biologische Vielfalt der Ökosysteme, die Ernährungssicherheit, die menschliche Gesundheit und verschlimmert Naturkatastrophen. Die Intensität und Häufigkeit von Naturgefahren werden zunehmen, hierbei ist ihre Verteilung aufgrund von Klimaveränderungen allerdings unregelmäßig; auch der Grad von Schadensanfälligkeiten und die Einteilung von Risikozonen werden sich zukünftig ändern.\\ Die Analyse von Naturgefahren, wie atmosphärische und hydrologische Ereignisse, kann zur Verbesserung des Krisenmanagements beitragen. Daher werden Satellitenbeobachtungen und simulierte Daten, die von verschiedenen atmosphärischen Modellen abgeleitet werden, für die Gefahr- und Risikomodellierung benötigt; dies kann Frühwarn- und Vorhersagesysteme unterstützen. Obwohl kontinuierliche Sensormessungen und Archivdaten (historische Daten/Klimadaten) für die Wettervorhersage in entwickelten Ländern zur Verfügung stehen, kamen es im Mai 2016 in der Nähe von Stuttgart in Süddeutschland bei einer katastrophalen Überschwemmung zu Verlusten von Menschenleben, die möglicherweise durch ein präzises Wetterwarnsystem vermeidbar gewesen wären. \\ Eine Echtzeitschätzung der geodätischen Weltraumtechnik wäre notwendig, um sie als Eingangsdaten in Wettervorhersagemodellen zu verwenden. Für die Analyse von raumgeodätischen Techniken in (nahezu) Echtzeit sind Vorhersagen der EOP unerlässlich. EOP werden durch das Rapid Service Prediction Centre des International Earth Rotation and Reference Systems Service (IERS) am USNO, Washington D.C., mit einer Verzögerung von Stunden bis Tagen zur Verfügung gestellt. Demzufolge wurden in der Vergangenheit mehrere Methoden für die EOP-Vorhersage entwickelt und angewendet. Die Genauigkeit dieser EOP-Vorhersagen ist jedoch nach wie vor - selbst für einen Vorhersagezeitraum von nur wenigen Tagen - unbefriedigend.\\ Um die Genauigkeit der EOP-Vorhersage zu verbessern, beschäftigt sich die vorliegende Studie mit der Untersuchung von der Vereinbarkeit von Erdrotationstheorien mit Beobachtungen. Darüber hinaus wird das Potenzial verschiedener geophysikalischer Phänomene analysiert, um die Wechselwirkungen verschiedener Prozesse, die die zeitabhängige Anregung der Erdrotation beeinflussen, besser zu verstehen.\\ Die meisten Theorien und Lösungen zur Erdrotation basieren auf der Lage der Hauptträgheitsachsen der Erde (PAI). Diese Position wird durch die Stokes-Koeffizienten zweiten Grades des Geopotentials, das mit Hilfe der Satellitenmission Gravity Recovery and Climate Experiment (GRACE) und der Satelliten-Laser-Entfernungsmessung (SLR) genau beobachtet wird, definiert. In dieser Studie wird zum ersten Mal die Entwicklung der Trägheitsachsen der Erde analysiert. Bemerkenswert an den vorgestellten Ergebnissen ist, daß sich die Trägheitsachsen während der Untersuchungsperiode nicht um eine mittlere Position, die in einem bestimmten terrestrischen Bezugsrahmen festgelegt ist, bewegen, sondern sich in nicht zu vernachlässigender Weise von ihrem ursprünglichen Position entfernen.\\ Darüber hinaus schlägt diese Studie einen neuartigen hybriden Ansatz zur EOP-Vorhersage vor. Es gibt eine gut eingeführte stochastische Methode, die “kopula-basierte Analyse”, die wir mit der “Singulär-Spektrum-Analyse” (SSA) für die EOP-Vorhersage kombiniert haben . Wir analysierten das Potenzial kopula-basierter Methoden zur Vorhersage von Erdrotationsparametern, die aus der Kombination verschiedener geodätischer Satellitensensoren und aus anderen geophysikalischen Parametern, wie z.B effektiven Drehimpulsen, abgeleitet werden. Die Kopula ist eine statistische Methode, die lineare und nicht-lineare Beziehungen zwischen zwei oder mehreren Variablen nutzt, indem eine theoretische Kopula-Funktion an eine empirische, bivariate oder multivariate Verteilungsfunktion angepasst wird. Wir haben eine hybride Vorhersagemethode entwickelt, die auch auf andere geophysikalische Parameter angewendet werden kann.\\ In dieser Studie wird der Zusammenhang zwischen der Bewegung des Himmelspols (CPM) und dem geomagnetischen Feld (GMF) untersucht, um die derzeitigen CPM-Vorhersagemethoden zu verbessern. Während des letzten Jahrzehnts wurden mehrere Untersuchungen durchgeführt, um eine mögliche Verbindung zwischen polaren Bewegungen und geomagnetischen Ausbrüten - hierbei handelt es sich um rasche Veränderungen der säkularen Variationen des GMF - zu erörtern. Weniger Aufmerksamkeit wurde jedoch den Auswirkungen der GMF-Änderungen auf die CPM, z.B. der Wechselbeziehung der geomagnetischen Ausbrüte, des geomagnetischen Dipolmoments, der geomagnetischen Feldelemente und der CPM-Variationen, gewidmet. In dieser Studie verwenden wir CPM-Zeitreihen, die aus Beobachtungen der Very Long Baseline Interferometry (VLBI) gewonnen wurden und aktuelle GMF-Daten, um die Korrelation zwischen CPM und GMF zu untersuchen. Unsere vorläufigen Ergebnisse zeigen einige auffallente Gemeinsamkeiten in den CPM- und GMF-Variationen, die das Potenzial besitzen, unser Verständnis des GMF-Beitrags zur Erdrotation zu verbessern. Alles in allem veranschaulichen die Ergebnisse mathematisch die Kohärenz zwischen den GMF-Parametern und der CPM und weisen damit perspektivisch den Weg für eine Verbesserung der EOP-Produkte.

Description: This study presents an enhancement to the Global Navigation Satellite Systems (GNSS) by integrating low Earth orbiters (LEOs) to a joint precise orbit determination (POD) processing. The Global Position System (GPS) operated by the United States is studied as a representative of all GNSS. The LEOs equipped with GNSS receivers supplement the receivers of the ground stations, especially for regions with a limited number of employed stations, which can be caused by various reasons. Due to the altitude and high velocity of LEOs, they not only contribute with additional observations, but also with a rapidly-changing observation geometry. Moreover, space-based observations have additional advantages over ground-based observations, e.g., signals are received without the impact of the troposphere. LEOs not only act as kinematic stations for GNSS satellites, but also bring additional orbit dynamics to the integrated system. The constraints caused by these orbit dynamics have an important impact on the determination of the orbits of the GNSS satellites and other parameters beyond that. In this thesis, the following topics are presented: 1) Background information and the basic principles related to the POD of GNSS satellites and LEOs, 2) the separated POD of GNSS satellites and LEOs, 3) the integrated POD, 4) the determination of the antenna phase center offsets (PCOs) of the GPS satellites and other geodetic parameters in the integrated POD. The orbit modeling and processing configuration used in this study for GNSS satellites and LEOs are verified to be compatible with state-of-the-art studies by the separated POD. The orbits of the GNSS satellites and LEOs reach an accuracy of a few centimeters and are comparable with the state-of-art studies. A more efficient outlier detection method has been developed to improve the position determined by using pseudo-range observations. In the study about the enhancement of the GPS orbits by integrating LEOs, a 26-station ground network in a global and sparse distribution is supplemented by different subsets of seven LEOs including GRACE-A/B, OSTM/Jason-2, Jason-3 and, Swarm-A/B/C. A 34% improvement of the GPS orbit in 1D-mean RMS (from 37.5 mm to 23.9 mm) is achieved by including the seven LEOs. Both the number of space-based observations and the LEOs' orbital geometry affect the GPS orbits where the orbital geometry is shown to be more important. The estimated GPS PCOs are also improved by including LEOs. For the x- and y-components of the GPS PCOs, the formal error is reduced significantly due to the additional observations and expanded nadir angle coverage brought by the LEOs during the periods of large solar-elevation angle. The z-component of the GPS PCOs (z-PCO) are strongly correlated with the scale of the terrestrial reference frame. By introducing the orbit dynamics of the seven LEOs to the processing without applying a no-net-scale constraint, the correlation coefficients between the GPS z-PCOs and the scale are reduced from 0.85 to 0.30. Consequently, the GPS z-PCOs can be estimated independently from the a-priori scale and a purely GNSS-based scale can be determined as well. A system-specific -25.5 cm offset of the GPS z-PCOs relative to the values offered by the International GNSS Service (IGS) is computed based on the seven-LEO-integrated solution. Another approach based on Galileo also solves this problem. The GPS satellites, multi-GNSS stations, and Galileo satellites with ground calibrated PCOs are processed jointly to calibrate the GPS z-PCOs and simultaneously determine a Galileo-based scale simultaneously. Based on the comparison and cross-check, a good agreement is shown between the LEO-based and Galileo-based methods. There is a slight improvement in the geocenter when including three Swarm satellites to the processing with about 80 ground stations over a half year. Based on the analysis in theory and the results derived from real data, an obvious enhancement to various aspects of GNSS by the integrated processing with LEOs is shown. More LEOs equipped with GNSS receivers and carefully calibrated PCOs are expected for further missions or even the next generation of GNSS.

Description: In dieser Arbeit wird eine Verbesserung der globalen Satellitennavigationssysteme (GNSS) durch die Einbindung von Satelliten in niedrigen Erdumlaufbahnen (LEOs) in eine gemeinsame präzise Bahnbestimmung (POD) vorgestellt. Das von den Vereinigten Staaten betriebene Global Positioning System (GPS) wird stellvertretend für alle GNSS untersucht. Die mit GNSS-Empfängern ausgestatteten LEOs ergänzen die Empfänger der Bodenstationen, vor allem in Regionen, in denen aus verschiedenen Gründen nur wenige Stationen verfügbar sind. Aufgrund der Orbithöhe und schnellen Bewegung der LEOs tragen diese nicht nur mit zusätzlichen Beobachtungen bei, sondern auch mit einer sich schnell verändernden Beobachtungsgeometrie. Darüber hinaus haben weltraumgestützte Beobachtungen zusätzliche Vorteile gegenüber bodengestützten Beobachtungen, z. B. werden Signale ohne den Einfluss der Troposphäre empfangen. LEOs stellen nicht nur kinematische Stationen für die GNSS-Satelliten dar, sondern bringen auch eine zusätzliche Bahndynamik in das integrierte System ein. Die durch diese Bahndynamik gegebenen Beschränkungen sind sowohl für die Bahnbestimmung der GNSS Satelliten als auch für weitere Parameter äußerst relevant. In dieser Arbeit werden die folgenden Themen behandelt: 1) Hintergrundinformationen und Grundprinzipien der POD von GNSS-Satelliten und LEOs, 2) eine separate POD von GNSS-Satelliten und LEOs, 3) eine integrierte POD, 4) die Schätzung der Antennen-Phasenzentrumsversätze (PCOs) der GPS-Satelliten und anderer geodätischer Parameter in der integrierten POD. Die separaten PODs bestätigen, dass die in dieser Studie verwendete Bahnmodellierungs- und Prozessierungskonfiguration der GNSS-Satelliten und LEOs mit dem aktuellen Stand der Forschung kompatibel ist. Die Bahnen der GNSS-Satelliten und LEOs erreichen eine Genauigkeit von wenigen Zentimetern. Es wurde eine effizientere Methode zur Erkennung von Ausreißern entwickelt, um die mit Hilfe von Pseudo-Range-Beobachtungen ermittelte Position zu verbessern. Ein Bodennetz mit 26 global dünn verteilten Stationen wird verwendet, um die Verbesserung der GPS-Bahnen durch die Integration von verschiedenen Teilgruppen der sieben LEOs GRACE-A/B, OSTM/Jason-2, Jason-3 und Swarm-A/B/C zu untersuchen. Bei der Einbeziehung aller sieben LEOs ergibt sich eine Verbesserung des 1D RMS Mittelwertes der GPS-Orbits von 34 % (von 37,5 mm auf 23,9 mm). Sowohl die Anzahl der weltraumgestützten Beobachtungen als auch die Geometrie der Bahnen der LEOs beeinflussen die GPS-Bahnen, wobei die Orbitgeometrie sich als der wichtigere Faktor erweist. Die geschätzten GPS PCOs werden durch die Einbeziehung von LEOs ebenfalls verbessert. Der formale Fehler der x- und y-Komponenten der GPS PCOs wird durch die zusätzlichen Beobachtungen und die größere Abdeckung des Nadirwinkels, den die LEOs während Perioden eines großen Sonnenstandswinkels mit sich bringen, erheblich reduziert. Die z-Komponente der GPS PCOs (z-PCO) ist mit dem Maßstabsfaktor des terrestrischen Referenzrahmens stark korreliert. Durch die Berücksichtigung der Bahndynamik der sieben LEOs in der Prozessierung werden ohne Fixierung des Maßstabes (d.h. ohne eine No-Net-Scale Bedingung) die Korrelationskoeffizienten zwischen den GPS z-PCOs und dem Maßstabsfaktor von 0,85 auf 0,30 reduziert. Folglich können zum einen die GPS z-PCOs unabhängig von einem externen Maßstab geschätzt werden und zum anderen kann ein rein GNSS-basierter Maßstabsfaktor bestimmt werden. Mit der integrierten Lösung mit sieben LEOs ergibt sich ein systemspezifischer Versatz der GPS z-PCOs von -25,5 cm relativ zu den vom International GNSS Service (IGS) veröffentlichten Werten. Ein anderer Ansatz basierend auf Galileo löst dieses Problem ebenfalls. Die GPS Satelliten, Multi-GNSS Bodenstationen und Galileo Satelliten mit bodenkalibrierten PCOs werden gemeinsam prozessiert, um die GPS z-PCOs zu kalibrieren und gleichzeitig einen Galileo-basierten Maßstabsfaktor zu bestimmen. Ein Vergleich zur Überprüfung zeigt eine hohe Übereinstimmung der LEO- und Galileo-basierten Methoden. Die Einbeziehung von drei Swarm Satelliten in eine Prozessierung mit etwa 80 Bodenstationen über ein halbes Jahr hinweg zeigt eine leichte Verbesserung des Geozentrums. Auf der Grundlage der theoretischen Analyse und der aus realen Daten abgeleiteten Ergebnisse zeigt sich eine deutliche Verbesserung verschiedener Aspekte der GNSS durch die Integration von LEOs. Es ist zu erwarten, dass mehr LEOs, ausgestattet mit GNSS-Empfängern und sorgfältig kalibrierten PCOs, für künftige Missionen oder sogar die nächste GNSS Generation eingesetzt werden.

Description: MAARE is an interdisciplinary research initiative to enhance our understanding of magma ascent, accumulation and reservoir evolution in intra-continental settings. Examples of core questions addressed by the MAARE research initiative comprise: · What are past and current conditions in transcrustal magmatic reservoirs at different depths? · How do magmatic fluids migrate through the crust and how do they trigger reservoir unrest? · What are the spatio-temporal controls on volcanism in low-flux systems? · What are realistic eruption scenarios and forecast uncertainties in low probability, high impact volcanic regions? · How can distributed volcanic fields be monitored in a comprehensive manner and how can small precursory signals reliably be interpreted? · What are pitfalls in communicating volcanic hazard research and risk? The aim of the lecture series is to develop a common understanding of the key questions, to develop new ideas and to initiate joint research projects.

Description: This deliverable summarises the methodology and results of the data collection for the European Fluid Atlas by the REFLECT project partners.

Description: The main objective of the work package 2 of the REFLECT project is to characterise relevant fluid properties and their reactions for saline fluids (type C). One of the specific goals was to collect fluid samples from several saline fluids from geothermal sites across Europe, determine their properties, and thus contribute to the Fluid Atlas (WP3). Additionally, the REFLECT team will compare those field data with data from lab experiments performed at near natural conditions. Samples of type C fluids were taken from several sites in Germany, Austria, Belgium and the Netherlands. The samples were analysed for major and minor ions, dissolved gases and isotopes.

Description: The Global Geodetic Reference Frame (GGRF) plays a fundamental role in geodesy and related Positioning, Navigation, and Timing applications, and allows to quantify the Earth’s change in space and time. The ITRF and ICRF are the two most important components to realize GGRF, while the determination of these two reference frames relies on the combination of several space geodetic techniques, mainly, VLBI, SLR, GNSS, and DORIS. The combination is currently done on either the parameter level, or the normal equation level. However, the combination on the observation level, or the so-called integrated processing of multi-technique on the observation level, provides the results of best consistency, robustness, and accuracy. This thesis focuses on the investigation of the integrated processing of GNSS and VLBI on the observation level. The benefits of integrated processing are demonstrated in terms of TRF, CRF, and EOP, while the impact of global ties (EOP), tropospheric ties, and local ties are underlined. Several issues in integrated processing are addressed, including the systematic bias in ties (for instance, LOD and tropospheric ties), the relative weighting. An automatic reweighting strategy based on the normalized residuals is developed, which can properly handle the uncertainty of the ties without losing too much constraint. A software with state-of-the-art modules is the prerequisite to perform integrated processing. Based on the GNSS data processing software: Positioning And Navigation Data Analyst (PANDA), the VLBI and SLR modules are implemented in the common least-squares estimator. Therefore, the best consistency can be guaranteed. The software capability is demonstrated with the single-technique solutions. The station coordinate precision is at millimeter level for both GNSS and VLBI, while the EOP estimates are comparable to other Analysis Centers and the IERS products. It is also demonstrated that the SLR station coordinate precision is improved by 20% to 30% with additional GLONASS and GRACE satellites to contributing to the LAGEOS and ETALON constellation. Focusing on the tropospheric ties in GNSS and VLBI integrated processing, its contribution is demonstrated for the first time comprehensively. Applying tropospheric ties improves the VLBI station coordinate precision by 12% on the horizontal components and up to 30% on the vertical component. The network scale repeatability is reduced by up to 33%. The EOP estimates are also improved significantly, for instance, 10% to 30% for polar motion, and up to 10% for other components. Furthermore, applying the gradient ties in the VLBI intensive sessions reduces the systematic bias in UT1-UTC estimates. The consistent TRF, CRF, and EOP are achieved in the integrated VLBI and GNSS solution. Applying the global ties, tropospheric ties, and local ties stables the reference frame. The ERP estimates in the integrated solution are dominated by the GNSS technique, and the VLBI technique introduces additional 10% improvement on the y-pole component in terms of the day-boundary-discontinuity. The UT1-UTC and celestial pole offsets are also slightly improved in the integrated solution. It is also demonstrated that applying the LTs inappropriately distorts the network and introduces systematic biases to the ERP estimates, addressing the necessity of updating the local surveys. Moreover, the coordinates of AGN are also enhanced by up to 20% in the integrated solutions, especially the southern ones. This study reveals the importance of integrated processing of multi-technique on the observation level, as the best consistency can be achieved, and the applied ties improve the solutions significantly. It is strongly recommended that for the future realization of celestial and terrestrial reference frames, the concept of integrated processing on the observation level should be implemented, and all the possible ties should be applied, including the global ties (EOP), local ties, space ties, and tropospheric ties. Such kind of integrated solution of all the four techniques can provide robust estimates of the reference frames and EOP, with the advantage of each technique exploited to its full extend.

Description: Der Globale Geodätische Referenzrahmen (Global Geodetic Reference Frame, GGRF) spielt eine fundamentale Rolle in der Geodäsie und den damit verbundenen Positionierungs-, Navigations- und Zeitmessungsanwendungen (Positioning, Navigation, and Timing, PNT) und ermöglicht die Quantifizierung der Veränderung der Erde in Raum und Zeit. Der ITRF und der ICRF sind die beiden wichtigsten Komponenten zur Realisierung des GGRF, wobei die Bestimmung dieser beiden Referenzrahmen auf der Kombination verschiedener raumgeodätischer Techniken beruht, hauptsächlich VLBI, SLR, GNSS und DORIS. Die Kombination wird derzeit entweder auf der Parameterebene oder auf der Normalgleichungsebene durchgeführt. Die Kombination auf der Beobachtungsebene oder die sogenannte integrierte Daten-Verarbeitung von Multi-Techniken auf der Beobachtungsebene, bietet jedoch eine Lösung mit der besten Konsistenz, Robustheit und Genauigkeit. Diese Arbeit konzentriert sich auf die Untersuchung der integrierten Daten-Verarbeitung von GNSS und VLBI auf der Beobachtungsebene. Die Vorteile der integrierten Lösung werden in Bezug auf TRF, CRF, und EOP aufgezeigt, während die Auswirkungen von „Global Ties (EOP), Tropospheric Ties, and Local Ties“ hervorgehoben werden. Einige Punkte der integrierten Verarbeitung werden in dieser Arbeit untersucht, einschließlich der systematischen Abweichungen von „Ties“ (z.B. LOD und Tropospheric Ties), der relativen Gewichtung usw. Anhand der normalisierten Residuen wird eine automatische Umgewichtungsstrategie entwickelt, mit der die Unsicherheit der „Ties“ angemessen behandelt werden kann, ohne dass zu viel Einschränkung dabei verloren geht. Eine Software mit modernsten Modulen ist die Voraussetzung für die integrierte Daten Verarbeitung. Basierend auf der GNSS-Datenverarbeitungssoftware Paket: Positioning And Navigation Data Analyst (PANDA) werden die Module VLBI und SLR in demselben Least-Squares-Estimator wie GNSS implementiert, damit kann man die beste Konsistenz in der Datenverarbeitung erreichen. In dieser Arbeit wird die Leistungsfähigkeit der Software mit den Ein-Technik-Lösungen demonstriert. Die Genauigkeit der Stationskoordinaten liegt sowohl für GNSS als auch für VLBI im Millimeterbereich, und die geschätzten EOP-Parameter sind auch mit der anderer Analysezentren und den IERS-Produkten vergleichbar. Es wird auch gezeigt, dass die Koordinatengenauigkeit der SLR-Station um 20-30% verbessert wird, wenn zusätzliche GLONASS- und GRACE-Satelliten zur LAGEOS und ETALON-Konstellation beitragen. Mit dem Schwerpunkt auf den „Tropospheric Ties“ in der integrierten GNSS- und VLBI- Daten Verarbeitung wird ihr Beitrag zum ersten Mal umfassend dargestellt. Die Anwendung der „Tropospheric Ties“ verbessert die Genauigkeit der VLBI-Koordinaten um 12% bei der horizontalen Komponente und bis zu 30% bei der vertikalen Komponente. Die Genauigkeit im Netzwerkmaßstab wird um bis zu 33% verbessert. Auch die EOP-Bestimmungen werden deutlich verbessert, z.B. um 10-30% bei polaren Bewegungen und bis zu 10% bei anderen Komponenten. Darüber hinaus reduziert die Einführung der „Gradient Ties“ in der VLBI-Intensivsession die systematische Abweichung in den dUT1-Bestimmungen. Die konsistente TRF, CRF, und EOP werden bei der integrierten VLBI- und GNSS-Lösung erreicht. Die Anwendung der „Global Ties, Tropospheric Ties and Local Ties“ stabilisiert die Bestimmungen des Referenzrahmens. Die ERP-Bestimmungen in der integrierten Lösung werden von der GNSS-Technik dominiert, und die VLBI-Technik bringt eine zusätzliche Verbesserung um 10% auf die Tagesgrenzen-Diskontinuität (day-boundary-discontinuity, DBD) für die y-Pol-Komponente. Die dUT1- und CPO werden in der integrierten Lösung ebenfalls leicht verbessert. Es wird auch gezeigt, dass eine ungeeignete Anwendung der LTs das Netzwerk verzerrt und systematische Abweichungen in die ERP-Bestimmungen einführt, wodurch die Notwendigkeit einer Aktualisierung der lokalen Tie Messungen deutlich wird. Darüber hinaus werden die Koordinaten der AGN in den integrierten Lösungen um bis zu 20% verbessert, insbesondere im Süden. Diese Arbeit zeigt die Bedeutung der integrierten Daten Verarbeitung von Multi-Technik auf der Beobachtungsebene, da die beste Konsistenz erreicht werden kann und die angewandten „Ties“ die Lösungen erheblich verbessern. Es wird nachdrücklich empfohlen, für die zukünftige Realisierung von himmelsfesten und erdfesten Referenzrahmen das Konzept der integrierten Verarbeitung auf Beobachtungsebene durchzuführen und alle möglichen „Ties“ anzuwenden, einschließlich der „Global Ties (EOP), Local Ties, Space Ties, and Tropospheric Ties“. Eine solche integrierte Lösung aller vier Techniken kann die robusten Bestimmungen der Referenzrahmen und der EOP liefern, wobei die Vorteile jeder Technik voll ausgeschöpft werden.

Description: South Wales is characterised by a rich variety of geologic formations and rocks of different ages and periods, and a large asymmetric syncline, as perhaps its most significant structural geological feature, extending from east to west over a length of approximately 96 km and 30 km from north to south, respectively. This oval-shaped syncline is part of the Variscan orogenic thrust and fold belt in Central Europe and covers some 2,700 km2, with coal-bearing rocks from the Upper Carboniferous (Westphalian Stage) deposited in the central syncline and older rocks outcropping in a peripheral belt around it. The coal-bearing sequence begins with Namurian grits and shales, overlain by the more productive Lower, Middle and Upper Coal Measures. A 3D structural geological model has been implemented for the central part of the South Wales Syncline and its bedrock geology. The oldest rocks in the model domain date back to the Pridoli Series from the uppermost Silurian, the youngest to the Westphalian Stage of the Upper Carboniferous. For model implementation, mainly open access data from the British Geological Survey (BGS) has been used. The final 3D structural geological model covers the entire Central South Wales Syncline and is 32.8 km wide and 36.6 km long. In total, the 3D model includes 21 fault zones and the elevation depth of ten surfaces: (1) Top Upper Coal Measures Formation; (2) Top Middle Coal Measures Formation; (3) Top Lower Coal Measures Formation; (4) Top Millstone Grit Group; (5) Top Dinantian Rocks; (6) Top Upper Devonian Rocks; (7) Top Lower Devonian Rocks (sandstone dominated); (8) Top Lower Devonian Rocks (mudstone dominated); (9) Top Pridoli Rocks; (10) Top Ludlow Rocks (in parts).

Description: This document presents the developed code, porousMedia4Foam, an open-source hydrogeochemical package that can decipher fluid flow and chemical reactive processes occurring within multi- {scale, dimensional, phase, compositional} environments. This report gives details regarding the installation of porousMedia4Foam, running the first simulations and describing many application cases in single-phase and multiphase systems.

Description: This brochure is designed for scientists and engineers of upcoming drilling projects and explains the key steps and important challenges in planning and executing continental scientific drilling.

Description: The 3D geomechanical-numerical modelling aims at a continuous description of the stress state in a subsurface volume. The model is fitted to the model-independent stress data records by adaptation of the displacement boundary conditions. This process is herein referred to as model calibration. Depending on the amount of available stress data records and the complexity of the model the calibration can be a lengthy process of trial-and-error to estimate the best-fit boundary conditions. The tool FAST Calibration (Fast Automatic Stress Tensor Calibration) is a Matlab script that facilitates and speeds up this calibration process. By using a linear regression it requires only three test model scenarios with different displacement boundary conditions to calibrate a geomechanical-numerical model on available stress data records. The differences between the modelled and observed stresses are used for the linear regression that allows to compute the displacement boundary conditions required for the best-fit estimation. The influence of observed stress data records on the best-fit displacement boundary conditions can be weighted. Furthermore, FAST Calibration provides a cross checking of the best-fit estimate against indirect stress information that cannot be used for the calibration process, such as the observation of borehole breakouts or drilling induced fractures. The script files are provided for download at http://github.com/MorZieg/FAST_Calibration. Tab. 0-1 gives an overview of the folder structure and input files with a short explanation.

Description: For the visualization and analysis of the stress field from 3D thermo-hydro-mechanical (THM) numerical model results two main technical steps are necessary. First, one has to derive from the six independent components of the 3D stress tensor scalar and vector values such as the orientation and magnitude of the maximum and minimum horizontal stress, stress ratios, or the differential stress. It is also of great interest to display e.g. the normal and shear stress with respect to an arbitrarily given surface. Second, an appropriate geometry should be given such as cross sections, profile e.g. for borehole pathways or surfaces on which the model results and further derived values are interpolated. This includes also the three field variables temperature, pore pressure and the displacement vector. To facilitate and automate these steps the Add-on GeoStress for the professional visualization software Tecplot 360 EX has been programmed. Besides the aforementioned values derived from the stress tensor the tool also allows to calculate the values of Coulomb Failure Stress (CFS), Slip and Dilation tendency (ST and DT) and Fracture Potential (FP). GeoStress also estimates kinematic variables such as horizontal slip, dip slip, rake vector of faults that are implemented as contact surfaces in the geomechanical-numerical model as well as the true vertical depth (TVD). Furthermore, the Add-on can import surface and polyline geometries and interpolates on these all available stress parameter. This technical report describes the visualization tool with examples using 3D geomechanical-numerical model results from the finite element software Abaqus v2019. It also presents a number of special features of Tecplot 360 EX in combination with GeoStress that allow a professional and efficient analysis. We also address now the usage GeoStress with PyTecplot which is a powerful tool to automize the analysis. The Add-on as well as the example and input files used in this manual is published by Stromeyer et al. (2020) and the table below gives an overview of the files with a short explanation as they appear in the manual.

Description: This deliverable summarises the methodology and results of the data collection for the European Fluid Atlas at a national level by the EFG’s linked third parties.

Description: This report compiles observations made within a time frame of two months on 24 representative thin-section samples representing the periods before and after 4- and 9-years of injection of CO2 into the reservoir. Given this short period of time until completion of this report, some observations and conclusions drawn have to be judged preliminary. Further analytical work and in-depth interpretation of the results are underway. Information provided for the period 0–4 years after CO2 injection include observations made by S. Bock in the framework of her not yet finished Ph.D. thesis.

Description: In geosciences the discretization of complex 3D model volumes into finite elements can be a time-consuming task and often needs experience with a professional software. In particular, low angle outcropping or out-pinching geological units, i.e. geological layers that are represented in the model volume, pose serious challenges. Another example are changes in the geometry of a model, which can occur at one point of a project, when re-meshing is not an option anymore or would involve a significant amount of additional time to invest. In order to speed up and automate the process of discretization, Apple PY (Automatic Portioning Preventing Lengthy manual Element assignment for PYthon) separates the process of mesh-generation and unit assignment. It requires an existing mesh together with separate information on the depths of the interfaces between geological units (herein called horizons). These two pieces of information are combined and used to assign the individual elements to different units. The uniform mesh is created with a standard meshing software and has to be available as an Abaqus input file. The information on the horizons depths and lateral variations in the depths is provided in a text file. Apple PY compares the element location and depth with that of the horizons in order to assign each element to a corresponding geological unit below or above a certain horizon. The script files are provided for download at http://github.com/MorZieg/APPLE_PY. Table 0-1 gives an overview of the folder structure and input files with a short explanation.

Description: This document describes the type of data collected in the REFLECT project, the standards used and how the data is curated. It also elaborates on the relations to IPR requirements and exploitation strategies. All data from the project shall be deposited in research data repositories according to the FAIR guiding principles for scientific data management and stewardship such that it is possible for third parties to access, mine, exploit, reproduce and disseminate — free of charge for any user.

Description: Proficiency testing (PT) is one of the few ways for an analytical laboratory to assess data quality under routine operating conditions. Here we report the results of Round 1 of the G-Chron PT programme, which is sponsored by the International Association of Geoanalysts. G-Chron is the first PT scheme devoted to the U-Th-Pb dating of mineral phases, primarily zircon, in geological materials. In this first round of G-Chron a total of 72 geochronology laboratories received the test material “Rak-17”, which previously had been characterized by seven well-established isotope dilution TIMS laboratories. A total of 63 of the PT participating laboratories reported data by the 15 December 2019 deadline. Here we both report and assess the measurement results submitted to this round. Our analysis provides a means for participating laboratories to assess their individual performance in relation to the isotope ages assigned, the experimental fitness-for-purpose criteria proposed by the scheme’s organisers and the results of similar laboratories participating in this round.

Description: The Lower Rhine Embayment in western Germany is one of the most important areas of earthquake recurrence north of the Alps, facing a moderate level of seismic hazard in the European context but a significant level of risk. This study deals with the impact of a scenario earthquake with a moment magnitude of 6.5 occurring along the Erft fault system south-west to the city of Cologne, the fourth largest German city with more than one million inhabitants and accommodating important industrial facilities. Since the city is located on thick layers of Quarternary sediments, the geological discontinuities at depth will have a significant influence on the duration and the amplification of ground-motion. Based on a new, harmonized and spatially highly resolved, model of the sedimentary cover, the sensitivity of spectral intensity measures to the site response analysis method is assessed employing random vibration theory approaches. Corresponding damage calculations are conducted in terms of European Macroseismic Scale (EMS-98) damage grades. Residential buildings and buildings with mixed residential and commercial occupancy are included in the corresponding calculations only, in line with most seismic risk assessment studies which have traditionally focused on residential typologies. Results from the damage calculations are presented in terms of number of buildings exposed to bands of EMS-98 intensity levels and probabilities of EMS-98 damage grades for residential buildings and buildings with mixed residential and commercial occupancy. Casualties in the city and the neighboring districts are estimated by means of the PAGER empirical method using population counts at the quartier (“Stadtviertel”) level in Cologne, the “Bezirk” level in Bonn and Aachen and at the municipality (“Gemeinde”) level for the surrounding areas, all of these comprised within the district (“Regierungsbezirk”) of Cologne.

Description: CaTeNA – Climatic and Tectonic Natural Hazards in Central Asia – is an interdisciplinary, international project funded by the German Ministry of Education and Research to study natural hazards in Central Asia. Central Asia is one of the most tectonically active regions of the world and is influenced by both the west wind zone and monsoon. CaTeNA is examining the two most serious natural hazards arising from these conditions: Earthquakes and mass movements. The project goal is to better understand the underlying processes and triggering factors and to better estimate the resulting risks. For this purpose, CaTeNA localises tectonic faults and determines deformation rates and their changes. Focus is put on two of the most active fault systems, the Main Pamir Thrust and the Darvaz Fault crossing Tajikistan and Kyrgyzstan. We try to estimate recurrence intervals of large earthquakes and to understand their relationship to mass movements using paleo-seismology, geomorphology and remote sensing. The current deformation field is characterised and quantified using the methods of space geodesy and seismology. The results will be incorporated into the openly accessible Central Asian Tectonic Database developed within the project, making it accessible to the public, stakeholders and decision-makers. They form the basis for a more accurate estimation of the risk for earthquakes and landslides. Another important project goal is the development and implementation of a dynamic risk assessment for landslides, including high-resolution, model-based precipitation and snowmelt maps. This allows for an improved estimation of the effects of geological hazards on inhabited areas and traffic infrastructure. Direct and efficient risk communication is achieved through interactive visualisation based on a dynamic multilingual web GIS platform. This is an essential step on the path to an early-warning system that takes into account the most important triggering factors. This data repository provides pdf files and recorded videos of talks presented during the final online workshop of the project.

Description: This document defines and prioritises the key objectives of dissemination of REFLECT and details the steps to be taken during the project’s lifetime in order to achieve maximum impact and reach relevant audiences. It also sets the framework to facilitate communication among Consortium members, and between the Consortium and stakeholders or the general public.

Description: This document corresponds to Deliverable D6.2 of the ongoing Horizon 2020 project REFLECT and is part of the Work Package 6. The deliverable “Stakeholder matrix” aims to define the approach for engaging stakeholders and involving them into the project in the most efficient way in order to achieve quality final results and successful implementation of the project final product. The document defines the main groups of the potential stakeholders and provides general guidelines on how to categorise them, how to establish the first contact and how to engage them.

Description: The basic website of the REFLECT project was launched at the end of March 2020, three months after the project’s start. The website was conceived to support the launch of the project, providing a project overview and information about the partners involved. The final version of the website delivered in June 2020 includes more detailed information about the project’s objectives, approach, dissemination material and links to the project’s social media channels. This document describes the website elements. These elements can (and will) evolve with time, to ensure the best possible interaction with users during the project lifetime.

Description: In recent years, an extensive network of Remotely Operated Multi-Parameter Stations (ROMPS) has been installed in different countries and climatic zones. The stations were developed by GFZ for various applications and set up together with the corresponding partners in the particular regions. In this sense, the general station with its core functionality (querying and storing of sensor data, transmission of data to a central storage unit, providing sufficient energy for the station) is referred as ROMPS. Various sensor systems to account for different application requirements can be connected to these stations. The ROMPS can then be, e.g., a tide gauge station, a buoy or a hydrometeorological (HyMet) station. This document provides the description of the data records from the meteorological system of the ROMPS. In the years after the first development of the data format for the German-Indonesian Tsunami Early Warning System GITEWS (tide gauge stations and buoys), the system was also used for other projects like the Global Change Observatory GCO and Advanced Remote Sensing – Ground-truth Demo and Test Facilities ACROSS (hydrometeorological stations). This resulted in a further development or adaptation of the system, so that different versions of the original data format were created. The versions differ primarily in the data representation (binary or ASCII) and the number and storage of metadata. The meteorological parameters have remained the same since the type of sensor has not changed. All data from the sensor is requested by the meteod software program according to a pre-selected sampling rate and stored in files on the station's computer. These files will be transmitted to a central data storage using file-oriented TCP/IP services (scp, ncftp). The scope of this document is to describe the data format and content which is available at the remote ROMPS. The data format description section is divided into subsections to account for the different format versions of the tide gauges, buoys and HyMet stations. This document is also the basis for further handling of the data, e.g. processing of data within the central data storage or warning center.

Description: An extensive network of Remotely Operated Multi-Parameter Stations (ROMPS) has been installed in the last years providing meteorological and hydrological data. Most of the stations are part of the Regional Research Network “Water in Central Asia” (CAWA) funded by the German Federal Foreign Office but additional funding was provided by GFZ through the “Global Change Observatory – Central Asia” (GCO) and the “Advanced Remote Sensing – Ground-truth Demo and Test Facilities” (ACROSS) projects of the Helmholtz Association. In spite of various projects, the technical setup of the stations is largely identical. There are minor differences in the selection of the sensors due to different applications. This means that all measurement parameters do not necessarily have to be available at each station. Usually, a standard set of meteorological sensors such as air temperature, relative humidity, air pressure, wind speed and direction, precipitation, solar radiation, soil moisture, and soil temperature are installed but this can be expanded to include other sensors like a snow measuring system or river discharge system. All data from the hydrometeorological system are sampled by a Campbell datalogger on each station according to a pre-selected sampling rate and written to files. The software requesting the data from the datalogger and writing them to files is called crd. The files are transmitted to a central data storage unit using file-oriented TCP/IP services (scp, ncftp) at GFZ and to the open access web-based Sensor Data Storage System (SDSS). The scope of this document is to describe the data format coming from the ROMPS. Additionally, this document is the basis for processing of data within the SDSS.

Description: This deliverable presents the logo and the style guide of the REFLECT project. It defines the visual identity of the project and establishes a standard visual style to ensure consistency and maximise outreach.

Description: The GEOFON program consists of a global seismic network (GE Network), a seismological data centre (GEOFON DC) and a global earthquake monitoring system (GEOFON EQinfo). These three pillars are part of the MESI research infrastructure of the Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences aiming at facilitating scientific research. GEOFON provides realtime seismic data, access to its own and third party data from the archive facilities as well as global and rapid earthquake information. The GEOFON Seismological Software can be considered a fourth cross-cutting module of the GEOFON Program. Data, services, products and software openly distributed by GEOFON are used by hundreds of scientists and data centres worldwide. Its earthquake information service is accessed directly by tens of thousands of visitors. The SeisComP software package is the flagship software provided to the community, which is geared for seismic observatory and data centre needs and used extensively to support our internal operations. As all other MESI (Modular Earth Science Infrastructure) modules GEOFON has the majority of users outside the GFZ as well as an external advisory committee that provides advice to the GFZ Executive Board and to the GEOFON team. This report describes the main activities carried out within the three GEOFON pillars and the software development group.

Description: For the visualization and analysis of the stress field from 3D thermo-hydro-mechanical (THM) numerical model results two main technical steps are necessary. First, one has to derive from the six independent components of the 3D stress tensor scalar and vector values such as the orientation and magnitude of the maximum and minimum horizontal stress, stress ratios, or the differential stress. It is also of great interest to display e.g. the normal and shear stress with respect to an arbitrarily given surface. Second, an appropriate geometry should be given such as cross sections, profile e.g. for borehole pathways or surfaces on which the model results and further derived values are interpolated. This includes also the three field variables temperature, pore pressure and the displacement vector. To facilitate and automate these steps the Add-on GeoStress for the professional visualization software Tecplot 360 EX has been programmed. Besides the aforementioned values derived from the stress tensor the tool also allows to calculate the values of Coulomb Failure Stress (CFS), Slip and Dilation tendency (ST and DT) and Fracture Potential (FP). GeoStress also estimates kinematic variables such as horizontal slip, dip slip, rake vector of faults that are implemented as contact surfaces in the geomechanical-numerical model as well as the true vertical depth (TVD). Furthermore, the Add-on can import surface and polyline geometries and interpolates on these all available stress parameter. This technical report describes the visualization tool with examples using 3D geomechanical-numerical model results from the finite element software Abaqus v2019. It also presents a number of special features of Tecplot 360 EX in combination with GeoStress that allow a professional and efficient analysis. We also address now the usage GeoStress with PyTecplot which is a powerful tool to automize the analysis. The Add-on as well as the example and input files used in this manual is published by Stromeyer et al. (2020) and the table below gives an overview of the files with a short explanation as they appear in the manual.

Description: In summer 2017, the ICDP SUSTAIN project (Surtsey Underwater volcanic System for Thermophiles, Alteration processes and INnovative concretes), drilled three cored boreholes (Table 1) through Surtsey at sites ≤10 m from a cored hole obtained in 1979. Drilling through the still hot volcano was carried out with an Atlas Copco CS1000 drill rig, whose components were transported by helicopter to Surtsey and re-assembled on site. The first vertical borehole, SE-02a, was cored in HQ diameter to 152 meters below surface (m b.s.) during August 7-16. It was terminated due to borehole collapse. A second vertical (SE-02b) cored borehole was then drilled in HQ diameter to 192 m during August 19-26. Wireline borehole logging in SE-02b was performed August 26. The anodized NQ-sized aluminum tubing of the Surtsey Subsurface Observatory was installed in SE-02b to 181 m depth on August 27. A third borehole, SE-03, angled 35° from vertical and directed 264°, was drilled from August 28 to September 4 and reached a measured depth of 354 m (~290 m vertical depth) under the eastern crater. The core is HQ diameter to a measured depth of 213 m and NQ diameter from 213-354 m measured depth. The core traverses the deep conduit and intrusions of the volcano to a total vertical depth of 290 m b.s. Seawater drilling fluid for boreholes SE-02a and SE-02b was filtered and doubly UV-sterilized at the drill site. No mud products were employed while coring SE-02a, while small amounts of attapulgite mud were used in SE-02b and SE-03. Core samples for geochemical analyses of pore water and microbiological investigations were collected on site from all three boreholes. About 650 m of core was transported by helicopter to Heimaey, 18 km northeast of Surtsey, to a processing laboratory where the core was scanned, documented, and described. Additional core processing has taken place at the Náttúrufraedistofnun Íslands, the Icelandic Institute of Natural History in Gardabaer, where both the 1979 and 2017 cores are stored.

Description: Length: 32 min What forms the landscapes of the Earth with its mountains, rivers, soils, the places we live in? Is Earth’s surface shaped when rocks are uplifted by geologic forces, and are then destroyed by rain, ice, and wind; or do plants with their roots, animals that dig into soil and the vast number of microorganisms shape the landscapes? Watch the scientists of the German-Chilean “EarthShape” project study these questions along a fascinating landscapes in Chile, and in their home laboratories. A science movie designed and produced by Friedhelm von Blanckenburg from GFZ Potsdam, Germany, Kirstin Übernickel from Universität Tübingen, and Wolfgang Dümcke from Filmbüro Potsdam, Germany, within the DFG-funded research network “EarthShape – Earth Surface Shaping by Biota” which is coordinated by Todd Ehlers (Universität Tübingen) und Friedhelm von Blanckenburg (GFZ Potsdam).

Description: Deliverable D5.2 presents the experimental outcome of jetting experiments at simulated reservoir conditions. Different rock types are tested under various conditions with the use of three different types of test bench. At first jetting experiments are conducted under submerged conditions in order to derive a better understanding of the governing erosion mechanism. Therefore pitting tests are combined with PIV measurements in order to derive and explain the erosion pattern of the occurring cavitation erosion and why the rock is more like to be eroded by the stagnation pressure of the impinging jet. Second, jetting experiments under pressure controlled conditions are performed. Rate of penetrations (ROP) of up to 100 m/h can be achieved which proofs the successful application of RJD technology especially in sand stone reservoir rock types. Especially the rotating nozzle design bears the highest potential for jetting operations where the static nozzle designs tend to fail, especially when pore pressure increases. The third experimental series under application of a bi- axial stress field show that the current RJD technology, as being used by project partner WSG, is not able to penetrate harder sandstone rock types (e.g. Dortmund sandstone) when field operating conditions are applied. The induced stress in the specimen does not initiate or enhance ROP. A second experiment thereby shows that higher nozzle exit speeds can lead to massive breakouts. Fourth, experiments are performed under a tri-axial stress field in collaboration with TU DELFT. Rock cubes are tested under different and very severely stress regimes while jetting into them. Compared to tests at atmospheric conditions it can be stated that the application of a stress field does not enhance the erosion of rock. At last experiments are conducted with the project partner WSG in order to determine the jetability of the Icelandic Basalt rock type and Icelandic inter basalt sediment layer. The experiments show that already higher pump pressures result in higher jetting performance, hence making them jetable as previously not expected. Furthermore the experiments approved the feasibility of the planned field test in Iceland when the soft sediment layer is the target zone. All in all the experiments conducted with the RJD technology show different results at simulated reservoir conditions compared to those at atmospheric which are described in deliverable D5.1 (Hahn & Wittig, 2017). Therefor, further testing at conditions representing the reservoir conditions more closer are needed in order to better understand and analyze the jetting process downhole.

Description: In this deliverable, the objectives of the Imperial College team are to consider jetted boreholes in the context of conventional borehole wall-rock stability analysis and to utilise an in-house advanced combined finite-discrete element code to examine the wall-rock failure process for jetted holes. The geomechanical modelling of Lateral Stability in D7.2 presented here is in addition to the main focus on modelling the water-jetting breakdown of the rock itself, reported in D7.1.

Description: The aim of this research is to investigate the failure mechanism for different types of rock in the context of water jet drilling and to predict the jet-ability or assess the radial jet drilling (RJD) performance prior to drilling and at the well petrophysical analysis stage. The main approach is to numerically simulate the water jet drilling for different types of rock using ICL’s in-house fluid-solid coupling codes. The rock properties, CT-scan data and jetting results obtained from D4.1 (Bakker et al., 2018) and D5.1 (Hahn et al., 2017) provide a good foundation for the related numerical results.

Description: The GEOFON program consists of a global seismic network (GE Network), a seismological data centre (GEOFON DC) and a global earthquake monitoring system (GEOFON EQinfo). These three pillars are part of the MESI research infrastructure of the Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences aiming at facilitating scientific research. GEOFON provides real-time seismic data, access to its own and third party data from the archive facilities as well as global and rapid earthquake information. The GEOFON Seismological Software can be considered a fourth cross-cutting module of the GEOFON Program. Data, services, products and software openly distributed by GEOFON are used by hundreds of scientists and data centres worldwide. Its earthquake information service is accessed directly by tens of thousands of visitors. The SeisComP software package is the flagship software provided to the community, which is geared for seismic observatory and data centre needs and used extensively to support our internal operations. Like all other MESI (Modular Earth Science Infrastructure) modules GEOFON has the majority of users outside the GFZ as well as an external advisory committee that provides advice to the GFZ Executive Board and to the GEOFON team. This report describes the main activities carried out within the three GEOFON pillars and the software development group.