ALBERT

Description: The Regional Research Network „Water in Central Asia“ (CAWa) funded by the German Federal Foreign Office consists of 19 remotely operated multi-parameter stations (ROMPS) in Central Asia. These stations were installed by the German Research Centre for Geosciences (GFZ) in Potsdam, Germany in close cooperation with the Central-Asian Institute for Applied Geosciences (CAIAG) in Bishkek, Kyrgyzstan, the national hydrometeorological services in Uzbekistan and Tajikistan, the Ulugh Beg Astronomical Institute in Tashkent, Uzbekistan, and the Kabul Polytechnic University, Afghanistan. The primary objective of these stations is to support the establishment of a reliable data basis of meteorological and hydrological data especially in remote areas with extreme climate conditions in Central Asia for applications in climate and water monitoring. Up to now, ten years of data are provided for an area of scarce station distribution and with limited open access data which can be used for a wide range of scientific or engineering applications. This dataset provides different types of raw hydrometeorological data such as air temperature, relative humidity, air pressure, wind speed and direction, precipitation, solar radiation, soil moisture and soil temperature as well as snow parameters and river discharge information for selected sites. The data has not undergone any quality control mechanism and should, therefore, be seen as raw data. A visual inspection of the data set has been made and some errors and quality degradation are listed in Zech et al. (2020) but does not claim to be complete. A quality control is strongly recommended by the authors before using the data. Each station data has its own storage directory at the data dissemination server named with the abbreviation (4-letter code) of the station. The data is sampled with a 5-minute interval and stored in hourly files separated by the type of data. These files are then archived as monthly files named with the station abbreviation, type of data, year and month. After one year, these monthly files are further archived to a yearly file. A detailed description for the stations is provided by the Station Exposure Descriptions. Further information about the dataset can be found in Zech et al. (2020). All data is compiled as ASCII data in two different formats which are explained in the documents GITW-SSP-FMT-GFZ-003.pdf (for the stations ALAI, ALA6, and SARY) and CAWA-SSP-FMT-GFZ-006.pdf (for all other stations). Monthly, the data will be dynamically extended as long as data can be acquired from the stations. Additionally, the near real-time data can be displayed and downloaded without any registration from the Sensor Data Storage System (SDSS) hosted at the Central-Asian Institute for Applied Geosciences (CAIAG) in Bishkek, Kyrgyzstan.

Description: The data set provides GFZ VER13 orbits of altimetry satellites: ERS-1 (August 1, 1991 - July 5, 1996), ERS-2 (May 13, 1995 - February 27, 2006), Envisat (April 12, 2002 - April 8, 2012), TOPEX/Poseidon (September 23, 1992 - October 8, 2005), Jason-1 (January 13, 2002 - July 5, 2013) and Jason-2 (July 5, 2008 - April 5, 2015) derived at the time spans given at the GFZ German Research Centre for Geosciences (Potsdam, Germany) within the Sea Level phase 2 project of the European Space Agency (ESA) Climate Change Initiative using "Earth Parameter and Orbit System - Orbit Computation (EPOS-OC)" software (Zhu et al., 2004) and the Altimeter Database and processing System (ADS, http://adsc.gfz-potsdam.de/ads/) developed at GFZ. The orbits were computed in the ITRF2014 terrestrial reference frame for all satellites using common, most precise models and standards available and described below. The ERS-1 orbit is computed using satellite laser ranging (SLR) and altimeter crossover data, while the ERS-2 orbit is derived using additionally Precise Range And Range-rate Equipment (PRARE) measurements. The Envisat, TOPEX/Poseidon, Jason-1, and Jason-2 orbits are based on Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) and SLR observations. For Envisat, altimeter crossover data were used additionally at 44 of 764 orbital arcs with gaps in SLR and DORIS data. The orbit files are available in the Extended Standard Product 3 Orbit Format (SP3-c). Files are gzip-compressed. File names are given as sate_YYYYMMDD_SP3C.gz, where "sate" is the abbreviation (ENVI, ERS1, ERS2, JAS1, JAS2, TOPX) of the satellite name, YYYY stands for 4-digit year, MM for month and DD for day of the beginning of the file. More details on these orbits are provided in Rudenko et al. (2018) to which these orbits are supplementary material.

Description: The data set provides GFZ VER11 orbits of altimetry satellites ERS-1 (August 1, 1991 - July 5, 1996), ERS-2 (May 13, 1995 - February 27, 2006), Envisat (April 12, 2002 - April 8, 2012), Jason-1 (January 13, 2002 - July 5, 2013) and Jason-2 (July 5, 2008 - April 5, 2015) TOPEX/Poseidon (September 23, 1992 - October 8, 2005), derived at the time spans given at Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences within the Sea Level phase 2 project of the European Space Agency (ESA) Climate Change Initiative using "Earth Parameter and Orbit System - Orbit Computation (EPOS-OC)" software and the Altimeter Database and processing System (ADS, http://adsc.gfz-potsdam.de/ads/) developed at GFZ. The orbits were computed in the same (ITRF2008) terrestrial reference frame for all satellites using common, most precise models and standards available and described below. The ERS-1 orbit is computed using satellite laser ranging (SLR) and altimeter crossover data, while the ERS-2 orbit is derived using additionally Precise Range And Range-rate Equipment (PRARE) measurements. The Envisat, TOPEX/Poseidon, Jason-1 and Jason-2 orbits are based on Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) and SLR observations. The orbit files are available in the Extended Standard Product 3 Orbit Format (SP3-c, ftp://igscb.jpl.nasa.gov/igscb/data/format/sp3c.txt) Files are gzip-compressed. File names are given as sate_YYYYMMDD_SP3C.gz, where "sate" is the abbreviation (ENVI, ERS1, ERS2, JAS1, JAS2, TOPX) of the satellite name, YYYY stands for 4-digit year, MM stands for month and DD stands for day of the beginning of the file. More details on these orbits are provided in Rudenko et al. (2017)

Description: Heute wird GPS (Global Positioning System) routinemäßig für die Positionsbestimmung genutzt. Aber es lässt sich noch mehr machen mit GPS: Wasserflächen reflektieren aufgrund ihrer Leitfähigkeit einen Teil der einfallenden GPS-Satellitensignale. Diese reflektierten Signale überlagern die einfallenden direkten GPS-Signale. Es kann zu einer Interferenz zwischen dem direkten und reflektierten GPS-Signal kommen, welche periodische Amplitudenschwankungen verursacht. Im Normalfall versucht man diese Signale zu unterdrücken, da diese eine genaue Positionsbestimmung verschlechtern. Am GFZ ist der spezielle OpenGPS Empfänger entwickelt worden, der diese Amplitudenschwankungen mit hoher zeitlicher Auflösung aufzeichnen kann. Aus den gemessenen Amplitudenschwankungen und der bekannten Position von GPS-Empfänger und GPS-Satellit können relative Höhenschwankungen der Wasseroberfläche am Ort der Reflexion abgeleitet werden und dies mit bis zu wenigen Zentimetern Genauigkeit. Die Methode der GPS-Reflektometrie bietet damit die Möglichkeit, im ufer- und küstennahen Bereich See- und Meeresspiegeländerungen, wichtige klimarelevante Faktoren, zu überwachen. Die Methode lässt sich aber nicht nur für bodengestützte Fernerkundung einsetzen, sondern befindet sich auch in der Entwicklung für eine weltraumgestützte globale Überwachung des Meeresspiegels.

Description: In the context of Integrated Water Resources Management(IWRM), informed decision making requires accurate,timely, spatially extensive, consistent and wellunderstood data sets on climate, water and land resources.Earth observation technologies provide suchdata sets as well as methods and tools for the generationof high-quality data products to support planningand decision-making. This Policy Brief advocates theuse of Earth observation technologies and their integrationinto operational monitoring and decision-supportsystems in Central Asia based on examples fromthe CAWa project.

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: Long-term tide gauge records provide valuable insights to sea level variations, but interpretation requires an accurate determination of the associated vertical land motion. Within the Tide Gauge Benchmark Monitoring Working Group of the International GNSS Service, we performed a dedicated reprocessing (1994-2020) for GNSS stations co-located with tide gauges. Based on 341 stations the GFZ contribution to the third TIGA reprocessing provides vertical land motion rates for 230 stations at or close to recently active tide gauges. We limited the processing to GPS observations.