ALBERT

Beschreibung:    Many heterogeneous data are being distributed via the Web. The heterogeneous data that different suppliers produce make it difficult for users to find and share the data they need. Especially in the GIS, reuse and sharing are very difficult. In this study, the ontological methodology was used to overcome the semantic heterogeneity in the subsurface database system, which is one of Korea’s national geospatial information systems and essential for the prevention of diverse natural disasters. The subsurface ontology model, which consists of a generic concept, a measurement unit, a spatial model, and subsurface information, was developed using OWL-DL. Also, subsurface-data reasoning framework, which needs to query, interpret by Jena reasoning engine, and integrate thematic information in the interoperable repositories, open-source geospatial services (e.g. WMS, WFS), and external open-map services was implemented to raise a natural language-style sample query for the retrieval of boring hole or subsurface area in high liquefaction potential. In the future, this study will be expanded to establish domain ontology related to other natural hazards and semantic reasoning system for preventing these disasters by which semantic sharing could be made available in the national geospatial information system. Content Type Journal Article Pages 1-8 DOI 10.1007/s12518-011-0054-0 Authors Sanghoon Lee, Ubiquitous Land Implementation Research Division, Korea Institute of Construction Technology, 2311, Daehwa-dong, Goyang-shi, Geyounggi-do 411-712, Republic of Korea Journal Applied Geomatics Online ISSN 1866-928X Print ISSN 1866-9298

Beschreibung:    The carrier phase tracking loop is the primary focus of the current work. In particular, two carrier phase tracking techniques are compared, the standard phase tracking loop, i.e., the phase lock loop (PLL), and the extended Kalman filter (EKF) tracking loop. In order to compare these two different techniques and taking into consideration the different models adopted in each, it is important to bring them to one common ground. In order to accomplish this, the equivalent PLL for a given EKF has to be determined in terms of steady-state response to both thermal noise and signal dynamics. A novel method for experimentally calculating the equivalent bandwidth of the EKF is presented and used to evaluate the performance of the equivalent PLL. Results are shown for both the L1 and L5 signals. Even though the two loops are designed to track equivalent dynamics and to have equivalent carrier phase standard deviations, the EKF outperforms the equivalent PLL in terms of both the transient response and sensitivity. Content Type Journal Article Pages 1-11 DOI 10.1007/s10291-011-0222-z Authors Dina Reda Salem, Position, Location and Navigation (PLAN) Group, Department of Geomatics Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB, Canada Cillian O’Driscoll, Position, Location and Navigation (PLAN) Group, Department of Geomatics Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB, Canada Gérard Lachapelle, Position, Location and Navigation (PLAN) Group, Department of Geomatics Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB, Canada Journal GPS Solutions Online ISSN 1521-1886 Print ISSN 1080-5370

Beschreibung:    The Tampa Bay Ecosystem Services Demonstration Project (TBESDP) is part of the U.S. Environmental Protection Agency’s Ecosystem Services Research Program. The principal objectives of TBESDP are to (1) quantify the ecosystem services of the Tampa Bay watershed, (2) determine the value of ecosystem services to society, (3) predict the supply of ecosystem services under future scenarios of population growth and climate change, and (4) apply this knowledge through models and tools that will support the best informed environmental decisions possible. The scope and complexity of this project required intensive effort to establish which services can be quantified by applying existing models, data, and scientific literature and which services will require supporting research. Research priorities were assessed by: (1) developing and refining conceptual models of major ecosystems in the Tampa Bay region, (2) gathering input from stakeholders about the relative importance and values of various ecosystem services, (3) preparing and reviewing a bibliometric analysis of the volume of scientific literature relevant to the ecosystems and services of interest, and (4) evaluating an integrated analysis of importance, value, and availability of scientific information. This analysis led us to focus on two research priorities, seagrass-habitat functions as support for fishery production, and wetlands as regulators of water quality. Content Type Journal Article Pages 1-12 DOI 10.1007/s11852-011-0158-z Authors Marc Russell, U.S. Environmental Protection Agency, 1 Sabine Island Drive, Gulf Breeze, FL 32561, USA John Rogers, U.S. Environmental Protection Agency, 1 Sabine Island Drive, Gulf Breeze, FL 32561, USA Stephen Jordan, U.S. Environmental Protection Agency, 1 Sabine Island Drive, Gulf Breeze, FL 32561, USA Darrin Dantin, U.S. Environmental Protection Agency, 1 Sabine Island Drive, Gulf Breeze, FL 32561, USA James Harvey, U.S. Environmental Protection Agency, 1 Sabine Island Drive, Gulf Breeze, FL 32561, USA Janet Nestlerode, U.S. Environmental Protection Agency, 1 Sabine Island Drive, Gulf Breeze, FL 32561, USA Federico Alvarez, U.S. Environmental Protection Agency, 1 Sabine Island Drive, Gulf Breeze, FL 32561, USA Journal Journal of Coastal Conservation Online ISSN 1874-7841 Print ISSN 1400-0350

Beschreibung: Bernt, Matthias; Haus, Michael; Robischon, Tobias (Hrsg.) (2010): Stadtumbau komplex: Governance, Planung, Prozess Content Type Journal Article Pages 1-2 DOI 10.1007/s13147-011-0101-7 Authors Holger Schmidt, Technische Universität Kaiserslautern, Fachgebiet Stadtumbau und Ortserneuerung, Pfaffenbergstraße 95, 67663 Kaiserslautern, Deutschland Journal Raumforschung und Raumordnung Online ISSN 1869-4179 Print ISSN 0034-0111

Beschreibung:    Stand-alone, unaided, single frequency, single epoch attitude determination is the most challenging case of GNSS compass processing. For land vehicle applications, the baseline approximately lies in the plane of the local geodetic horizon. This provides an important constraint that can be exploited to directly aid the ambiguity resolution process. We fully integrate the constraint into the observation equations, which are transformed orthogonally. Our method can acquire the high-quality float solution by means of a heading search strategy. The fixed solution is obtained by weighted constrained integer least squares for each possible heading. The correct solution is identified by three consecutive steps: Kolmogorov–Smirnov test, heading verification, and global minimizer of the fixed ambiguity objective function. The analysis focuses on single frequency, single epoch land vehicle attitude determination using low-end GPS receivers with very low precision of carrier phase and code measurements. The error analysis is given for choosing a proper baseline length in practical application. Experimental results demonstrate that this scheme can improve the ambiguity success rate for very short baseline. Content Type Journal Article Pages 1-10 DOI 10.1007/s10291-011-0234-8 Authors Wantong Chen, School of Electronic and Information Engineering, Beihang University, Beijing, 100191 People’s Republic of China Honglei Qin, School of Electronic and Information Engineering, Beihang University, Beijing, 100191 People’s Republic of China Journal GPS Solutions Online ISSN 1521-1886 Print ISSN 1080-5370

Beschreibung:    The performance of real - time single-frequency precise point positioning is demonstrated in terms of position accuracy. This precise point positioning technique relies on predicted satellite orbits, predicted global ionospheric maps, and in particular on real-time satellite clock estimates. Results are presented using solely measurements from a user receiver on the L1-frequency (C1 and L1), for almost 3 months of data. The empirical standard deviations of the position errors in North and East directions are about 0.15 m, and in Up direction about 0.30 m. The 95% errors are about 0.30 m in the horizontal directions, and 0.65 m in the vertical. In addition, single-frequency results of six receivers located around the world are presented. This research reveals the current ultimate real-time single-frequency positioning performance. To put these results into perspective, a case study is performed, using a moderately priced receiver with a simple patch antenna. Content Type Journal Article Pages 1-8 DOI 10.1007/s10291-011-0228-6 Authors Roel J. P. van Bree, Delft University of Technology, Delft, The Netherlands Christian C. J. M. Tiberius, Delft University of Technology, Delft, The Netherlands Journal GPS Solutions Online ISSN 1521-1886 Print ISSN 1080-5370

Beschreibung:    Three GOCE-based gravity field solutions have been computed by ESA’s high-level processing facility and were released to the user community. All models are accompanied by variance-covariance information resulting either from the least squares procedure or a Monte-Carlo approach. In order to obtain independent external quality parameters and to assess the current performance of these models, a set of independent tests based on satellite orbit determination and geoid comparisons is applied. Both test methods can be regarded as complementary because they either investigate the performance in the long wavelength spectral domain (orbit determination) or in the spatial domain (geoid comparisons). The test procedure was applied to the three GOCE gravity field solutions and to a number of selected pre-launch models for comparison. Orbit determination results suggest, that a pure GOCE gravity field model does not outperform the multi-year GRACE gravity field solutions. This was expected as GOCE is designed to improve the determination of the medium to high frequencies of the Earth gravity field (in the range of degree and order 50 to 200). Nevertheless, in case of an optimal combination of GOCE and GRACE data, orbit determination results should not deteriorate. So this validation procedure can also be used for testing the optimality of the approach adopted for producing combined GOCE and GRACE models. Results from geoid comparisons indicate that with the 2 months of GOCE data a significant improvement in the determination of the spherical harmonic spectrum of the global gravity field between degree 50 and 200 can be reached. Even though the ultimate mission goal has not yet been reached, especially due to the limited time span of used GOCE data (only 2 months), it was found that existing satellite-only gravity field models, which are based on 7 years of GRACE data, can already be enhanced in terms of spatial resolution. It is expected that with the accumulation of more GOCE data the gravity field model resolution and quality can be further enhanced, and the GOCE mission goal of 1–2 cm geoid accuracy with 100 km spatial resolution can be achieved. Content Type Journal Article Pages 1-16 DOI 10.1007/s00190-011-0486-7 Authors Th. Gruber, Institute of Astronomical and Physical Geodesy, Technische Universität München, Arcisstrasse 21, 80333 Munich, Germany P. N. A. M. Visser, Delft Institute of Earth Observation and Space Systems (DEOS), Delft University of Technology, Kluyverweg 1, 2629 HS Delft, The Netherlands Ch. Ackermann, Institute of Astronomical and Physical Geodesy, Technische Universität München, Arcisstrasse 21, 80333 Munich, Germany M. Hosse, Institute of Astronomical and Physical Geodesy, Technische Universität München, Arcisstrasse 21, 80333 Munich, Germany Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    The efficacy of robust M-estimators is a well-known issue when dealing with observational blunders. When the number of observations is considerably large—long time series for instance—one can take advantage of the asymptotic normality of the M-estimation and compute reasonable estimates for the unknown parameters of interest. A few leading M-estimators have been employed to identify the most likely functional model for GPS coordinate time series. This includes the simultaneous detection of periodic patterns and offsets in the GPS time series. Estimates of white noise, flicker noise, and random walk noise components are also achieved using the robust M-estimators of (co)variance components, developed in the framework of the least-squares variance component estimation (LS-VCE) theory. The method allows one to compute confidence interval for the (co)variance components in asymptotic sense. Simulated time series using white noise plus flicker noise show that the estimates of random walk noise fluctuate more than those of flicker noise for different M-estimators. This is because random walk noise is not an appropriate noise structure for the series. The same phenomenon is observed using the results of real GPS time series, which implies that the combination of white plus flicker noise is well described for GPS time series. Some of the estimated noise components of LS-VCE differ significantly from those of other M- estimators. This reveals that there are a large number of outliers in the series. This conclusion is also affirmed by performing the statistical tests, which detect (large) parts of the outliers but can also leave parts to be undetected. Content Type Journal Article Pages 1-19 DOI 10.1007/s00190-011-0489-4 Authors A. Khodabandeh, Department of Surveying and Geomatics Engineering, Geodesy Division, Faculty of Engineering, University of Tehran, North Kargar Ave., Amir-Abad, Tehran, Iran A. R. Amiri-Simkooei, Department of Surveying Engineering, Faculty of Engineering, University of Isfahan, 81746-73441 Isfahan, Iran M. A. Sharifi, Department of Surveying and Geomatics Engineering, Geodesy Division, Faculty of Engineering, University of Tehran, North Kargar Ave., Amir-Abad, Tehran, Iran Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    A major engineering challenge for mines experiencing significant seismicity is the performance of the support systems. This paper provides a critical review of dynamic testing techniques used for understanding and quantifying the performance of ground support systems. This review focuses on testing rigs in Canada, Australia and South Africa. The different laboratory testing rigs are listed along with their characteristics and their advantages and disadvantages. The paper concludes with recommendations towards developing a more unified strategy to understand and eventually forecast the behaviour of support systems under dynamic loads. Content Type Journal Article Pages 1-14 DOI 10.1007/s00603-011-0155-4 Authors John Hadjigeorgiou, Lassonde Institute for Mining, University of Toronto, Room 121, 170 College Street, Toronto, ON, M5S 3E3, Canada Yves Potvin, Australian Centre for Geomechanics, P O Box 3296, Broadway, Nedlands, WA 6009, Western Australia Journal Rock Mechanics and Rock Engineering Online ISSN 1434-453X Print ISSN 0723-2632

Beschreibung:    The Global Navigation Satellite System Reflectometry (GNSS-R) concept was conceived as a means to densify radar altimeter measurements of the sea surface. Until now, the GNSS-R concept relied on open access to GNSS transmitted codes. Recently, it has been proposed that the ranging capability of the technique for ocean altimetric applications can be improved by using all the signals transmitted in the bandwidth allocated to GNSS, which includes open access as well as encrypted signals. The main objective of this study is to provide experimental proof of this enhancement through a 2-day experiment on the Zeeland Bridge (The Netherlands). In the experiment, we used a custom built GNSS-R system, composed of high gain GPS antennas, calibration subsystem, and an FPGA-based signal processor which implemented the new concepts, an X-band radar altimeter and a local geodetic network. The results obtained indicate that the new approach produces a significant improvement in GNSS-R altimetric performance. Content Type Journal Article Pages 1-11 DOI 10.1007/s10291-011-0225-9 Authors Antonio Rius, Institut d’Estudis Espacials de Catalunya-CSIC, Campus UAB, Fac. Ciencias, Torre C5 parell 2, 08193 Bellaterra, Spain Oleguer Nogués-Correig, Institut d’Estudis Espacials de Catalunya-CSIC, Campus UAB, Fac. Ciencias, Torre C5 parell 2, 08193 Bellaterra, Spain Serni Ribó, Institut d’Estudis Espacials de Catalunya-CSIC, Campus UAB, Fac. Ciencias, Torre C5 parell 2, 08193 Bellaterra, Spain Estel Cardellach, Institut d’Estudis Espacials de Catalunya-CSIC, Campus UAB, Fac. Ciencias, Torre C5 parell 2, 08193 Bellaterra, Spain Santi Oliveras, Institut d’Estudis Espacials de Catalunya-CSIC, Campus UAB, Fac. Ciencias, Torre C5 parell 2, 08193 Bellaterra, Spain Enric Valencia, Institut d’Estudis Espacials de Catalunya-UPC, Campus Nord, Jordi Girona 1-3, 08034 Barcelona, Spain Hyuk Park, Institut d’Estudis Espacials de Catalunya-UPC, Campus Nord, Jordi Girona 1-3, 08034 Barcelona, Spain José Miguel Tarongí, Institut d’Estudis Espacials de Catalunya-UPC, Campus Nord, Jordi Girona 1-3, 08034 Barcelona, Spain Adriano Camps, Institut d’Estudis Espacials de Catalunya-UPC, Campus Nord, Jordi Girona 1-3, 08034 Barcelona, Spain Hans van der Marel, Institute of Earth Observation and Space Systems, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS Delft, The Netherlands Roel van Bree, Institute of Earth Observation and Space Systems, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS Delft, The Netherlands Bas Altena, Institute of Earth Observation and Space Systems, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS Delft, The Netherlands Manuel Martín-Neira, European Space Research and Technology Centre, Keplerlaan 1, 2200 AG Noordwijk, The Netherlands Journal GPS Solutions Online ISSN 1521-1886 Print ISSN 1080-5370

Beschreibung:    The effect of specimen size on the measured unconfined compressive strength and other mechanical properties has been studied by numerous researchers in the past, although much of this work has been based on specimens of non-standard dimensions and shapes, and over a limited size range. A review of the published literature was completed concentrating on the presentation of research pertaining to right cylindrical specimens with height:diameter ratios of 2:1. Additionally, new data has been presented considering high strength (70 MPa) cement mortar specimens of various diameters ranging from 63 to 300 mm which were tested to failure. Currently, several models exist in the published literature that seek to predict the strength–size relationship in rock or cementitious materials. Modelling the reviewed datasets, statistical analysis was used to help establish which of these models best represents the empirical evidence. The findings presented here suggest that over the range of specimen sizes explored, the MFSL (Carpinteri et al. in Mater Struct 28:311–317, 1995 ) model most closely predicts the strength–size relationship in rock and cementitious materials, and that a majority of the empirical evidence supports an asymptotic value in strength at large specimen diameters. Furthermore, the MFSL relationship is not only able to model monotonically decreasing strength–size relationships but is also equally applicable to monotonically increasing relationships, which although shown to be rare do for example exist in rocks with fractal distributions of hard particles. Content Type Journal Article Pages 1-17 DOI 10.1007/s00603-011-0161-6 Authors William J. Darlington, Department of Civil Engineering, Monash University, Clayton, VIC, Australia Pathegama G. Ranjith, Department of Civil Engineering, Monash University, Clayton, VIC, Australia S. K. Choi, CSIRO Earth Science and Resource Engineering, Bayview Avenue, Clayton, VIC, Australia Journal Rock Mechanics and Rock Engineering Online ISSN 1434-453X Print ISSN 0723-2632

Beschreibung:    We examine the electromagnetic coupling of a GPS antenna–monument pair in terms of its simulated affect on long GPS coordinate time series. We focus on the Earth and Polar Observing System (POLENET) monument design widely deployed in Antarctica and Greenland in projects interested particularly in vertical velocities. We base our tests on an absolute robot calibration that included the top ~0.15 m of the monument and use simulations to assess its effect on site coordinate time series at eight representative POLENET sites in Antarctica over the period 2000.0–2011.0. We show that the neglect of this calibration would introduce mean coordinate bias, and most importantly for velocity estimation, coordinate noise which is highly sensitive to observation geometry and hence site location and observation period. Considering only sub-periods longer than 2.5 years, we show vertical site velocities may be biased by up to ±0.4 mm/year, and biases up to 0.2 mm/year may persist for observation spans of 8 years. Changing between uniform and elevation-dependent observation weighting alters the time series but does not remove the velocity biases, nor does ambiguity fixing. The effect on the horizontal coordinates is negligible. The ambiguities fixed series spectra show noise between flicker and random walk with near-white noise at the highest frequencies, with mean spectral indices (frequencies 〈20 cycles per year) of approximately −1.3 (uniform weighting) and −1.4 (elevation-dependent weighting). While the results are likely highly monument specific, they highlight the importance of accounting for monument effects when analysing vertical coordinate time series and velocities for the highest precision and accuracy geophysical studies. Content Type Journal Article Pages 1-11 DOI 10.1007/s00190-011-0491-x Authors Matt A. King, School of Civil Engineering and Geosciences, Newcastle University, Cassie Building, Newcastle upon Tyne, NE1 7RU UK Michael Bevis, School of Earth Sciences, Ohio State University, 125 South Oval Mall, Columbus, OH 43210-1522, USA Terry Wilson, School of Earth Sciences, Ohio State University, 125 South Oval Mall, Columbus, OH 43210-1522, USA Bjorn Johns, UNAVCO, 6350 Nautilus Drive, Boulder, CO 80301-5554, USA Frederick Blume, UNAVCO, 6350 Nautilus Drive, Boulder, CO 80301-5554, USA Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    A new algorithm for single receiver DCB estimation using GIM vertical TEC gridded values is proposed. It estimates receiver DCB and vertical residual ionospheric delays using the least squares approach with linear constraints. The performance of the proposed algorithm was assessed by comparing estimated receiver DCBs with those provided by the IGS. The same comparisons were done using two other algorithms for receiver DCB estimation. It is demonstrated that the proposed algorithm is capable of reproducing IGS DCB values at the level of 0.1–0.3 ns, which is better than the level of agreement observed for the other two algorithms. For our tests, we considered data from more than 100 IGS stations, daily, such that all major regions of the world were covered. Besides, both ionospherically quiet and disturbed days were considered. It provides some evidence that the aforementioned level of agreement with IGS receiver DCB values does not significantly dependent on geographical region and the state of the ionosphere. The algorithm is easy to implement and can be considered for online use. Content Type Journal Article Pages 1-10 DOI 10.1007/s10291-011-0230-z Authors Maxim Keshin, School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU UK Journal GPS Solutions Online ISSN 1521-1886 Print ISSN 1080-5370

Beschreibung:    In this paper, a cross-shore profile evolution model, Uniform Beach Sediment Transport-Time-Averaged Cross-Shore (UNIBEST-TC), is used. The model was developed at WL/Delft hydraulic laboratory in the Netherlands. The model is used to predict wave height in a barred beach (Egmond site, The Netherlands) and the results show that there is a good agreement between the measured and predicted values by the model. In the present study, Morlet wavelet is used to distinguish the breaking waves; it is integrated over frequency to provide the temporal variation of localized total energy. The study shows that the local peaks of the energy densities correspond to the events of wave breaking in the predicted–wave time series. Furthermore, the wave energy distribution shows a tendency to decrease in the off-shore direction of the inner bar. Content Type Journal Article Pages 1-7 DOI 10.1007/s11852-011-0157-0 Authors Mohamed A. K. Elsayed, College of Engineering and Technology, Arab Academy for Science & Technology and Maritime Transport [Arab League], Mail Code (2033) El-Horeya, El-moshir Ahmed Ismail St., Misr El-gidida, Cairo, Egypt Journal Journal of Coastal Conservation Online ISSN 1874-7841 Print ISSN 1400-0350

Beschreibung:    Seventeen long series of tidal gravity observations with superconducting gravimeters (SGs) belonging to the GGP network allowed to determine the main tidal waves generated by the tidal potential of third degree in the Diurnal (M1), Semi-Diurnal (3MK2, 3MO2) and Ter-Diurnal (M3) bands with a precision of 0.1%, although the amplitudes of these waves are below 10 nm s −2 (1 μgal). Special analysis techniques have been used to separate M1, 3MK2 and 3MO2 from the neighbouring waves generated by the second degree potential. The 11 European stations form a geographically homogeneous subgroup and it is thus possible to derive some conclusions concerning the ocean tides loading and the body tides models. The results for M1, 3MK2 and 3MO2 are not in contradiction with the recent models and the results for M3 are even in agreement with them. Content Type Journal Article Pages 1-11 DOI 10.1007/s00190-011-0492-9 Authors Bernard Ducarme, Georges Lemaître Centre for Earth and Climate Research, Catholic University of Louvain, 3 Chemin du Cyclotron, 1348 Louvain-la-Neuve, Belgium Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    Future satellite missions dedicated to measuring time-variable gravity will need to address the concern of temporal aliasing errors; i.e., errors due to high-frequency mass variations. These errors have been shown to be a limiting error source for future missions with improved sensors. One method of reducing them is to fly multiple satellite pairs, thus increasing the sampling frequency of the mission. While one could imagine a system architecture consisting of dozens of satellite pairs, this paper explores the more economically feasible option of optimizing the orbits of two pairs of satellites. While the search space for this problem is infinite by nature, steps have been made to reduce it via proper assumptions regarding some parameters and a large number of numerical simulations exploring appropriate ranges for other parameters. A search space originally consisting of 15 variables is reduced to two variables with the utmost impact on mission performance: the repeat period of both pairs of satellites (shown to be near-optimal when they are equal to each other), as well as the inclination of one of the satellite pairs (the other pair is assumed to be in a polar orbit). To arrive at this conclusion, we assume circular orbits, repeat groundtracks for both pairs of satellites, a 100-km inter-satellite separation distance, and a minimum allowable operational satellite altitude of 290 km based on a projected 10-year mission lifetime. Given the scientific objectives of determining time-variable hydrology, ice mass variations, and ocean bottom pressure signals with higher spatial resolution, we find that an optimal architecture consists of a polar pair of satellites coupled with a pair inclined at 72°, both in 13-day repeating orbits. This architecture provides a 67% reduction in error over one pair of satellites, in addition to reducing the longitudinal striping to such a level that minimal post-processing is required, permitting a substantial increase in the spatial resolution of the gravity field products. It should be emphasized that given different sets of scientific objectives for the mission, or a different minimum allowable satellite altitude, different architectures might be selected. Content Type Journal Article Pages 1-18 DOI 10.1007/s00190-011-0493-8 Authors D. N. Wiese, Colorado Center for Astrodynamics Research, University of Colorado at Boulder, 431 UCB, Boulder, CO 80309, USA R. S. Nerem, Colorado Center for Astrodynamics Research, University of Colorado at Boulder, 431 UCB, Boulder, CO 80309, USA F. G. Lemoine, NASA Goddard Space Flight Center, Planetary Geodynamics Laboratory, Greenbelt, MD 20771, USA Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    The consistency of the Chang’E-1 and SELENE reference frames as realized by the footprint positions of laser altimetry measurements of the lunar surface during both missions was analyzed using a global 12-parameter model for small (with respect to unity) deformations and rigid body motions. The rigid body motion and deformation parameters between the two reference frames estimated from nearly-colocated without tie measurements are found to be consistent, i.e., nearly zero for the estimates of the translations, rotations and shear parameters. However, the estimated three strain parameters, which are similar in magnitude and sign, reveal a prominent scale difference, between the Chang’E-1 and SELENE reference frames, of about 0.9 × 10 −5 . The scale difference can be attributed to calibration of the data sets using the known coordinates of the lunar laser ranging stations all located on the near side of the Moon. Content Type Journal Article Pages 1-9 DOI 10.1007/s00190-011-0495-6 Authors H. Bâki Iz, Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hong Kong, China Y. Q. Chen, Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hong Kong, China C. K. Shum, Division of Geodetic Science, School of Earth Sciences, The Ohio State University, Columbus, USA X. L. Ding, Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hong Kong, China B. A. King, Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hong Kong, China W. Chen, Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hong Kong, China M. Berber, Department of Civil, Environmental, and Geomatics Engineering, Florida Atlantic University, Boca Raton, USA Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung: Comments on “Estimating the Strength of Jointed Rock Masses” by Lianyang Zhang Content Type Journal Article Pages 1-6 DOI 10.1007/s00603-011-0152-7 Authors Ergin Arıoğlu, Yapı Merkezi R&D Department, Hacı Resit Pasa Sok. No:7, Camlıca, 34676 Istanbul, Turkey Gözde Kurt, Yapı Merkezi R&D Department, Hacı Resit Pasa Sok. No:7, Camlıca, 34676 Istanbul, Turkey Sanem Kayalı, Yapı Merkezi R&D Department, Hacı Resit Pasa Sok. No:7, Camlıca, 34676 Istanbul, Turkey Journal Rock Mechanics and Rock Engineering Online ISSN 1434-453X Print ISSN 0723-2632

Beschreibung:    An exact closed form solution is derived for the mechanical behaviour of a linear viscoelastic Burgers rock around an axisymmetric tunnel, supported by a linear elastic ring. Analytical formulae are provided for the displacement of the rock/lining interface and for the pressure exerted by the rock on the lining, taking into account the stiffness and its installation time. Results calculated from these formulae do validate the corresponding numerical results of a 2D finite differences code. Further, comparison to previous existing solutions for the same viscoelastic model indicates similarities and differences. A parametric study is performed to investigate the effect of the viscoelastic constants, the stiffness and installation time of the support. The derived closed form solution is used to construct the time-dependent Supported Ground Reaction Curves of the viscoelastic rock, i.e. the time contour plots on the convergence confinement diagram. The importance of the effect of the support on the restrained rock creep and the exerted pressure on the lining, during the design life of a structure, is examined. Content Type Journal Article Pages 1-12 DOI 10.1007/s00603-011-0159-0 Authors Pavlos Nomikos, Division of Mining Engineering, School of Mining and Metallurgy, National Technical University, 9 Iroon Polytechneiou St, Zografou, 157 80 Athens, Greece Reza Rahmannejad, Mining Department, Shahid Bahonar University of Kerman-Iran, Kerman, Iran Alexandros Sofianos, Division of Mining Engineering, School of Mining and Metallurgy, National Technical University, 9 Iroon Polytechneiou St, Zografou, 157 80 Athens, Greece Journal Rock Mechanics and Rock Engineering Online ISSN 1434-453X Print ISSN 0723-2632

Beschreibung:    This paper adopts a global perspective to investigate external relations of German cities, both transnationally and on the national scale. At the centre of the analysis are the locational strategies of major advanced producer service firms that link the cities in which they operate through a multitude of flows. Using an interlocking network model and data on the organizational structure of leading business service firms, the paper measures and interprets the extent to which German cities were integrated in the world city network in 2008. The global positions and national network patterns of 14 major German cities are explored, as well as the sectoral strengths and geographical orientations of their external relations. The paper concludes with an assessment of the trajectory of German cities in the world city network between the turn of the twenty-first century and the onset of the current financial crisis. The analysis reveals a geography of advanced producer services that is polycentric in character but does not map directly onto the distribution of other metropolitan functions. In a longitudinal perspective, German cities experienced an absolute and relative decline in global network connectivity between 2000 and 2008, which raises questions about the changing strategic importance of German cities in the world city network. Content Type Journal Article Pages 1-13 DOI 10.1007/s13147-011-0100-8 Authors Michael Hoyler, Department of Geography, Loughborough University, LE11 3TU Loughborough, UK Journal Raumforschung und Raumordnung Online ISSN 1869-4179 Print ISSN 0034-0111

Beschreibung: Henckel, Dietrich; von Kuczkowski, Kester; Lau, Petra; Pahl-Weber, Elke; Stellmacher, Florian (Hrsg.) (2010): Planen – Bauen – Umwelt. Ein Handbuch Content Type Journal Article Pages 1-2 DOI 10.1007/s13147-011-0089-z Authors Peter Müller, Wissenschaftliches Referat III „Natürliche Ressourcen, Umwelt, Ökologie“, Akademie für Raumforschung und Landesplanung – Leibniz-Forum für Raumwissenschaften, Hohenzollernstraße 11, 30161 Hannover, Deutschland Journal Raumforschung und Raumordnung Online ISSN 1869-4179 Print ISSN 0034-0111

Beschreibung:    The aim of the present study is the employment of the artificial neural network (ANN) model in the estimation and evaluation of geoid heights. For that reason, a number of control points with known orthometric heights in the region of North Greece were measured by GPS and used to test the presented algorithms. The derived ANN geoid heights are compared to those produced by a well-known conventional method through a combined gravimetric geoid. In order to evaluate the computed heights, numerical tests were carried out for points distributed inside and at the borders of the study area. The obtained results show that the ANN model is a competitive approach with certain advantages. Content Type Journal Article Pages 1-5 DOI 10.1007/s12518-011-0052-2 Authors Christos Pikridas, Department of Geodesy and Surveying, Aristotle University of Thessaloniki, Thessaloniki, Greece Aristidis Fotiou, Department of Geodesy and Surveying, Aristotle University of Thessaloniki, Thessaloniki, Greece Symeon Katsougiannopoulos, Department of Geodesy and Surveying, Aristotle University of Thessaloniki, Thessaloniki, Greece Dimitrios Rossikopoulos, Department of Geodesy and Surveying, Aristotle University of Thessaloniki, Thessaloniki, Greece Journal Applied Geomatics Online ISSN 1866-928X Print ISSN 1866-9298

Beschreibung:    Egypt has launched its first Earth remote sensing satellite EgyptSat-1 in 2007. A series of evaluations of the usefulness and limitations of EgyptSat-1 images for different applications are required. This research is concerned with the investigation of the geometric and cartographic potential of EgyptSat-1 image in order to know to what scale EgyptSat-1 image is suitable for map production and map updating. The geometrical accuracy of rectification of EgyptSat-1 based on non-parametric rectification (polynomial approach and rubber sheeting) has been evaluated. Four methods of rectification have been compared: different orders of 2D polynomials (first-order polynomial, second-order polynomial, third-order polynomial) and rubber sheeting method. Different sets of ground control points (observed with differential global positioning system) have been tested. Several experiments were performed to rectify EgyptSat-1 image using the four rectification methods. For each method, different numbers of ground control points (GCPs) were used starting at 15 points, and then the number was reduced each time till the minimum number of GCPs for each method is reached and with three different GCP distributions. Various issues such as the solutions, feasibility, accuracy, and requirements for control information are addressed. The results show that rubber sheeting followed by third-order polynomial then second-order polynomial then first-order polynomial gives the best root mean square error. Actually, a serious mapping should be based on a satisfying by the theory justified mathematical model so that rubber sheeting should not be used for a serious mapping even it shows smaller discrepancies, but for the flat test area, an approximate 2D transformation can be accepted. Also although third-order polynomial is accurate in the proximity of GCPs and shows smaller discrepancies compared to the first- and the second-order polynomials, they can lead to significant errors for regions outside the GCP range and should not be used for a serious mapping. One can be considered the best resulted rectified image that obtained from second-order polynomial followed by the first-order polynomial. It was found in our study area that the minimum number of control points for each method gives accuracy better than a pixel. The first-order polynomial and rubber sheeting are good from the economical cost that they use minimum number of control points (three). It was found that the planimetric accuracy of rectified EgyptSat image met the 1:25,000 mapping standard (National Map Accuracy Standards). Also from the assessment of the information content of the EgyptSat image, it was found that it is consistent with the map scale of 1:25,000. In conclusion by analysis of the results, it is obvious that EgyptSat images are able to produce and update map of scale 1:25,000. Content Type Journal Article Pages 1-11 DOI 10.1007/s12518-011-0050-4 Authors Ayman Rashad Elshehaby, Surveying Engineering, Banha University, Cairo, Egypt Lamyaa Gamal El-deen Taha, Aviation and Aerial Photography, National Authority of Remote Sensing and Space Science (NARSS), Cairo, Egypt Journal Applied Geomatics Online ISSN 1866-928X Print ISSN 1866-9298

Beschreibung:    Global Positioning System (GPS) plays a central role in solving the location-based needs of wheelchair users and efficient route guidance. An essential process in wheelchair navigation is matching the position obtained from GPS or other sensors on a sidewalk network. This process of map matching in turn assists in making decisions under uncertainty. However, GPS-based wheelchair navigation systems have difficulties in tracking wheelchairs in urban areas due to poor satellite availability. To overcome this, a fuzzy logic-based algorithm is applied to effectively perform matching wheelchair movements on sidewalks. Fuzzy logic, based on fuzzy reasoning concepts, in many circumstances can take noisy and imprecise input to yield numerically accurate output. Experiments on a university campus validate it practicable. Content Type Journal Article Pages 1-10 DOI 10.1007/s10291-011-0229-5 Authors Ming Ren, University of Pittsburgh, Pittsburgh, PA, USA Hassan A. Karimi, University of Pittsburgh, Pittsburgh, PA, USA Journal GPS Solutions Online ISSN 1521-1886 Print ISSN 1080-5370

Beschreibung:    Many studies in geography have demonstrated that results can vary according to scale and configuration of spatial units. However, implications of the MAUP—Modifiable Area Unit Problem—have received little attention in urban planning and policy studies. The first objective of this paper is to demonstrate how identification of poor areas (residential areas with 40% or more of low-income population) is sensitive to changes in scale. The second objective is to measure the completeness (to what degree targeting only poor areas is adequate to reach all the poor population of a metropolis) and the efficiency (to what degree the population benefitting from targeted interventions is poor) of area-based interventions. The methodology to identify poverty areas is based on three spatial levels of analysis: dissemination areas (DAs), census tracts (CTs) and districts, namely micro, meso and macro levels. Hierarchical linear models are used to analyze the variance partitioned between these levels. Results of multilevel analyses demonstrate that CTs are more heterogeneous on the basis of DAs than Zones according to CTs. Independently of the scale of analysis, results show that the majority of low income population is living in areas with no poverty concentration in Montréal (completeness dimension). Moreover, results show that about half of the population living in zones of poverty concentration is not poor even when micro-zones are used for measurement (efficiency dimension). These results illustrate the importance of scale in identifying poverty areas which also have implications for social policy interventions. Content Type Journal Article Pages 1-21 DOI 10.1007/s12061-011-9068-6 Authors Anne-Marie Séguin, Institut national de la recherche scientifique, Centre Urbanisation Culture Société, 385, rue Sherbrooke Est, Montréal, Québec H2X 1E3, Canada Philippe Apparicio, Spatial Analysis and Regional Economics Laboratory, Institut national de la recherche scientifique, Centre Urbanisation Culture Société, 385, rue Sherbrooke Est, Montréal, Québec H2X 1E3, Canada Mylène Riva, Axe Santé des Populations et Environnementale, Centre de Recherche du Centre Hospitalier Universitaire de Québec and Université Laval, 2875 Boulevard Laurier Édifice Delta 2, bureau 600, Québec, G1V 2M2 Québec, Canada Journal Applied Spatial Analysis and Policy Online ISSN 1874-4621 Print ISSN 1874-463X

Beschreibung:    Although GNSS techniques are theoretically sensitive to the Earth center of mass, it is often preferable to remove intrinsic origin and scale information from the estimated station positions since they are known to be affected by systematic errors. This is usually done by estimating the parameters of a linearized similarity transformation which relates the quasi-instantaneous frames to a long-term frame such as the International Terrestrial Reference Frame (ITRF). It is well known that non-linear station motions can partially alias into these parameters. We discuss in this paper some procedures that may allow reducing these aliasing effects in the case of the GPS techniques. The options include the use of well-distributed sub-networks for the frame transformation estimation, the use of site loading corrections, a modification of the stochastic model by downweighting heights, or the joint estimation of the low degrees of the deformation field. We confirm that the standard approach consisting of estimating the transformation over the whole network is particularly harmful for the loading signals if the network is not well distributed. Downweighting the height component, using a uniform sub-network, or estimating the deformation field perform similarly in drastically reducing the amplitude of the aliasing effect. The application of these methods to reprocessed GPS terrestrial frames permits an assessment of the level of agreement between GPS and our loading model, which is found to be about 1.5 mm WRMS in height and 0.8 mm WRMS in the horizontal at the annual frequency. Aliased loading signals are not the main source of discrepancies between loading displacement models and GPS position time series. Content Type Journal Article Pages 1-14 DOI 10.1007/s00190-011-0487-6 Authors Xavier Collilieux, IGN/LAREG et GRGS, 6-8 av. Blaise Pascal, 77455 Marne La Vallée Cedex 2, France Tonie van Dam, University of Luxembourg, 162a, avenue de la Faïencerie, 1511 Luxembourg, Luxembourg Jim Ray, NOAA National Geodetic Survey, 1315 East-West Hwy, Silver Spring, MD 20910, USA David Coulot, IGN/LAREG et GRGS, 6-8 av. Blaise Pascal, 77455 Marne La Vallée Cedex 2, France Laurent Métivier, IGN/LAREG et GRGS, 6-8 av. Blaise Pascal, 77455 Marne La Vallée Cedex 2, France Zuheir Altamimi, IGN/LAREG et GRGS, 6-8 av. Blaise Pascal, 77455 Marne La Vallée Cedex 2, France Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    The LLL reduction of lattice vectors and its variants have been widely used to solve the weighted integer least squares (ILS) problem, or equivalently, the weighted closest point problem. Instead of reducing lattice vectors, we propose a parallel Cholesky-based reduction method for positive definite quadratic forms. The new reduction method directly works on the positive definite matrix associated with the weighted ILS problem and is shown to satisfy part of the inequalities required by Minkowski’s reduction of positive definite quadratic forms. The complexity of the algorithm can be fixed a priori by limiting the number of iterations. The simulations have clearly shown that the parallel Cholesky-based reduction method is significantly better than the LLL algorithm to reduce the condition number of the positive definite matrix, and as a result, can significantly reduce the searching space for the global optimal, weighted ILS or maximum likelihood estimate. Content Type Journal Article Pages 1-18 DOI 10.1007/s00190-011-0490-y Authors Peiliang Xu, Disaster Prevention Research Institute, Kyoto University, Uji, Kyoto, 611-0011 Japan Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    The Gravity and steady-state Ocean Circulation Explorer (GOCE) satellite mission measures Earth’s gravity field with an unprecedented accuracy at short spatial scales. In doing so, it promises to significantly advance our ability to determine the ocean’s general circulation. In this study, an initial gravity model from GOCE, based on just 2 months of data, is combined with the recent DTU10MSS mean sea surface to construct a global mean dynamic topography (MDT) model. The GOCE MDT clearly displays the gross features of the ocean’s steady-state circulation. More significantly, the improved gravity model provided by the GOCE mission has enhanced the resolution and sharpened the boundaries of those features compared with earlier satellite only solutions. Calculation of the geostrophic surface currents from the MDT reveals improvements for all of the ocean’s major current systems. In the North Atlantic, the Gulf Stream is stronger and more clearly defined, as are the Labrador and the Greenland currents. Furthermore, the finer scale features, such as eddies, meanders and branches of the Gulf Stream and North Atlantic Current system are visible. Similar improvements are seen also in the North Pacific Ocean, where the Kuroshio and its extension are well represented. In the Southern hemisphere, both the Agulhas and the Brazil-Malvinas Confluence current systems are well defined, and in the Southern ocean the Antarctic Circumpolar Current appears enhanced. The results of this preliminary analysis, using an initial GOCE gravity model, clearly demonstrate the potential of the GOCE mission. Already, at this early stage of the mission, the resolution of the MDT has been improved and the estimated surface current speeds have been increased compared with a GRACE satellite-only MDT. Future GOCE gravity models are expected to build further upon this early success. Content Type Journal Article Pages 1-19 DOI 10.1007/s00190-011-0485-8 Authors P. Knudsen, Technical University of Denmark, DTU Space, 2100 Copenhagen, Denmark R. Bingham, School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, UK O. Andersen, Technical University of Denmark, DTU Space, 2100 Copenhagen, Denmark Marie-Helene Rio, CLS, Space Oceanography Division, Ramonville-St-Agne, France Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    The network-based real-time kinematic (RTK) positioning has been widely used for high-accuracy applications. However, the precise point positioning (PPP) technique can also achieve centimeter to decimeter kinematic positioning accuracy without restriction of inter-station distances but is not as popular as network RTK for real-time engineering applications. Typically, PPP requires a long initialization time and continuous satellite signals to maintain the high accuracy. In case of phase breaks or loss of signals, re-initialization is usually required. An approach of instantaneous cycle slips fixing using undifferenced carrier phase measurements is proposed, which leads to instantaneous re-initialization for real-time PPP. In the proposed approach, various errors such as real-time orbit and clock errors, atmosphere delay and wind-up effects are first refined and isolated from integer cycle slips. The integer values of cycle slips can then be estimated and fixed with the LAMBDA technique by applying a cascade cycle slip resolution strategy. Numerical experiments with different user dynamics are carried out to allow a comprehensive evaluation of efficiency and robustness of the cycle slip fixing algorithm. The results show that the cycle slips can be fixed correctly in all cases considered and that data gaps of up to 300 s can be connected with high confidence. As a result, instantaneous re-initialization is achieved in the real-time PPP processing. Content Type Journal Article Pages 1-13 DOI 10.1007/s10291-011-0233-9 Authors Zhang Xiaohong, School of Geodesy and Geomatics, Wuhan University, 129 Luoyu Road, Wuhan, 430079 China Li Xingxing, School of Geodesy and Geomatics, Wuhan University, 129 Luoyu Road, Wuhan, 430079 China Journal GPS Solutions Online ISSN 1521-1886 Print ISSN 1080-5370

Beschreibung:    Based on the geometric analysis of the relationship between the stress state at a point and the yield surface defined in the principal stress space, a coefficient ω is set up as an estimation index to describe the stress-induced yield risk. After yield, the equivalent plastic shear strains is usually used to characterize the failure degree (FD) of the material and adopted here as an index of the damage degree for the surrounding rock masses. Then, a unified variable combining ω and FD, named failure approaching index (FAI), is constructed to estimate the stability of rock mass which may be at different deformation stages. The formulas of FAI are derived for some popular yield criteria in geomechanics. Details for such development are addressed in the paper. Its rationality is verified by numerical simulation and comparative analysis of the conventional triaxial compression tests and typical tunnel projects. In addition, the method for applying FAI to the stability estimation of surrounding rock mass is proposed. As examples, the stability of the underground powerhouse, access tunnels and headrace tunnels at the Jinping II hydropower station are estimated by making use of the method we presented. The results indicate that not only is the index rational in mechanics, but the theory also has good expansibility, and the estimation methods are simple and practical as well. It is easier for field engineers to analyze and understand the numerical results. Content Type Journal Article Pages 1-14 DOI 10.1007/s00603-011-0150-9 Authors C. Q. Zhang, State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, 430071 People’s Republic of China H. Zhou, State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, 430071 People’s Republic of China X. T. Feng, State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, 430071 People’s Republic of China Journal Rock Mechanics and Rock Engineering Online ISSN 1434-453X Print ISSN 0723-2632

Beschreibung:    The analysis of tracking loops for global navigation satellite systems (GNSS) receivers is often confined to Monte Carlo approaches that can result in long simulation times and a limited number of simulation runs. A different approach based on Semi-Analytic principles is considered here. Matlab ® code implementing a Semi-Analytic framework for the fast simulation of GNSS digital tracking loops is presented. The code structure is detailed and two specific examples implementing a standard PLL and the Double Estimator for unambiguous binary offset carrier (BOC) tracking are provided. The code has been organized in a modular way, and can be easily modified for the simulation of different tracking loops. Content Type Journal Article Pages 1-5 DOI 10.1007/s10291-011-0221-0 Authors Daniele Borio, PLAN Group, Department of Geomatics Engineering, University of Calgary, Calgary, AB, Canada Pratibha B. Anantharamu, PLAN Group, Department of Geomatics Engineering, University of Calgary, Calgary, AB, Canada Gérard Lachapelle, PLAN Group, Department of Geomatics Engineering, University of Calgary, Calgary, AB, Canada Journal GPS Solutions Online ISSN 1521-1886 Print ISSN 1080-5370

Beschreibung:    Emergency response is a complex activity involving many actors and heterogeneous spatial data. Two of the major challenges are the integration and extraction of these data and their transmission to emergency management actors. Although significant progress has been made regarding the systemic and syntactic heterogeneity of data in this context, semantic heterogeneity remains insufficiently addressed. Here, we discuss the possibility of applying the ontology to resolve semantic heterogeneity in emergency response. We propose a concept for a solution to the semantic interoperability problem in emergency management using an ontology by presenting a case study. Content Type Journal Article Pages 1-14 DOI 10.1007/s12518-011-0048-y Authors Zhengjie Fan, Web Information Systems, EWI, Delft University of Technology, Mekelweg 4, 2628 CD, Delft, The Netherlands Sisi Zlatanova, Section GIS-technology, OTB, Delft University of Technology, Jaffalaan 9, 2628 BX, Delft, The Netherlands Journal Applied Geomatics Online ISSN 1866-928X Print ISSN 1866-9298

Beschreibung:    During the last 2 decades, Global Positioning System (GPS) measurements have become a very important data-source for ionospheric studies. However, it is not a direct and easy task to obtain accurate ionospheric information from these measurements because it is necessary to perform a careful estimation of the calibration constants affecting the GPS observations, the so-called differential code biases (DCBs). In this paper, the most common approximations used in several GPS calibration methods, e.g. the La Plata Ionospheric Model (LPIM), are applied to a set of specially computed synthetic slant Total Electron Content datasets to assess the accuracy of the DCB estimation in a global scale scenario. These synthetic datasets were generated using a modified version of the NeQuick model, and have two important features: they show a realistic temporal and spatial behavior and all a-priori DCBs are set to zero by construction. Then, after the application of the calibration method the deviations from zero of the estimated DCBs are direct indicators of the accuracy of the method. To evaluate the effect of the solar activity radiation level the analysis was performed for years 2001 (high solar activity) and 2006 (low solar activity). To take into account seasonal changes of the ionosphere behavior, the analysis was repeated for three consecutive days close to each equinox and solstice of every year. Then, a data package comprising 24 days from approximately 200 IGS permanent stations was processed. In order to avoid unwanted geomagnetic storms effects, the selected days correspond to periods of quiet geomagnetic conditions. The most important results of this work are: i) the estimated DCBs can be affected by errors around ±8 TECu for high solar activity and ±3 TECu for low solar activity; and ii) DCB errors present a systematic behavior depending on the modip coordinate, that is more evident for the positive modip region. Content Type Journal Article Pages 1-8 DOI 10.1007/s00190-011-0477-8 Authors Juan Federico Conte, GESA, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, CONICET, Paseo del bosque s/n, 1900 La Plata, Argentina Francisco Azpilicueta, GESA, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, CONICET, Paseo del bosque s/n, 1900 La Plata, Argentina Claudio Brunini, GESA, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, CONICET, Paseo del bosque s/n, 1900 La Plata, Argentina Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    This paper focuses on the study of the correlation between magnetic parameters with the level of contamination by heavy metals in urban soils. We report a magnetic investigation of urban soil samples from Merida, state of Yucatan, Southern Mexico. It appears that most of our samples contain ferrimagnetic minerals as the magnetic carriers, probably coming from the titanomagnetites/titanomaghemites series. This is inferred by the acquisition of isothermal remanent magnetization, which shows that most of samples are almost completely saturated at about 200 mT. The S −200 value (factor characterizing stability of remanent magnetization) is between 0.8 and 1.0, characteristic of ferrimagnetic minerals. The susceptibility vs. temperature measurements also point to some titanomaghemites and titanomagnetites as probable responsible for magnetization. On the other hand, measurements of magnetic susceptibility at high and low frequencies helped us to determine the high content of superparamagnetic grains in the majority of the samples, although not all of these showed high values of magnetic susceptibility. We found that the most contaminated samples by Pb and Zn showed the higher saturation isothermal remanent magnetization values, whereas the higher values in magnetic susceptibility correspond to samples contaminated by Cr. Finally, we noted that a high level in Sr decreases the magnetic susceptibility. Content Type Journal Article Pages 377-388 DOI 10.1007/s11200-011-0021-6 Authors Bertha Aguilar Reyes, Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Geofísica - Sede Michoacán, Universidad Nacional Autónoma de México, Campus Morelia, 58089 Morelia, Mexico Francisco Bautista, Laboratorio de Suelos y Agua, Centro de Investigaciones en Geografía Ambiental, Universidad Nacional Autónoma de México, Campus Morelia, 58089 Morelia, Mexico Avto Goguitchaichvili, Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Geofísica - Sede Michoacán, Universidad Nacional Autónoma de México, Campus Morelia, 58089 Morelia, Mexico Ofelia Morton, Laboratorio de Paleomagnetismo, Instituto de Geofísica, Universidad Nacional Autónoma de México, 04510 México D.F., Mexico Journal Studia Geophysica et Geodaetica Online ISSN 1573-1626 Print ISSN 0039-3169 Journal Volume Volume 55 Journal Issue Volume 55, Number 2

Beschreibung:    The Early Cretaceous may be considered a key period for understanding the evolution of the Earth’s magnetic field. Some still unsolved problems are related to the mode of paleosecular variation (PSV) of the Earth’s magnetic field before and during the Cretaceous Normal Superchron. We report here a detailed rock-magnetic, paleomagnetic and paleointensity investigation from 28 lava flows (331 standard paleomagnetic cores) collected in the Argentinean part of the Parana Flood Basalts (Formation Posadas) in order to contribute to the study of PSV during the early Cretaceous and to obtain precise Cretaceous paleomagnetic pole positions for stable South America. The average paleofield direction is precisely determined from 26 sites, which show small within-site dispersion and high directional stability. Five sites show evidences for the self-reversal of thermoremanent magnetization. 23 sites yielded normal polarity magnetization and only 3 are reversely magnetized. Moving windows averages were used to analyze the sequential variation of virtual geomagnetic pole’s (VGP) axial positions. Interestingly, the axial average VGP path traces an almost complete cycle around the geographical pole and passes near the location of all previously published Paraná Magmatic Province poles. Both paleomagnetic poles and average VGP paths are significantly different from the pole position suggested by fixed hotspot reconstructions, which may be due to true polar wander or the hotspot motion itself. Only 15 samples from 5 individual basaltic lava flows, yielded acceptable paleointensity estimates. The site mean paleointensities range from 25.2 ± 2.2 to 44.0 ± 2.2 µT. The virtual dipole moments (VDMs) range from 4.8 to 9.9 × 10 22 Am 2 . This correspond to a mean value of 7.7 ± 2.1 × 10 22 Am 2 which is 96% of the present day geomagnetic field strength. These intensities agree with the relatively high values already reported for Early Cretaceous, which are consistent with some inferences from computer simulations previously published. Content Type Journal Article Pages 279-309 DOI 10.1007/s11200-011-0016-3 Authors Mabel Mena, Instituto de Geofísica Daniel Valencio, Dpto. Ciencias Geológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina Avto Goguitchaichvili, Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Geofísica - Sede Michoacán, Universidad Nacional Autónoma de México, Campus Morelia, 58089 Morelia, Mexico Miguel Cervantes Solano, Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Geofísica - Sede Michoacán, Universidad Nacional Autónoma de México, Campus Morelia, 58089 Morelia, Mexico Juan Francisco Vilas, Instituto de Geofísica Daniel Valencio, Dpto. Ciencias Geológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina Journal Studia Geophysica et Geodaetica Online ISSN 1573-1626 Print ISSN 0039-3169 Journal Volume Volume 55 Journal Issue Volume 55, Number 2

Beschreibung:    In this work we try to better characterise the shallow magnetic signature of hydrocarbon microseepage in oil fields from eastern and western Venezuela. To get a better insight of the processes involved, we attempt to find out the main magnetic phases responsible for the observed oil-related shallow magnetic anomalies. In this way, a new and alternative numerical approach to decompose Isothermal Remagnetization (IRM) curves is introduced. The method is based on a Direct Signal Analysis (DSA) of the IRM curve in order to identify the number and type of magnetic components. Representative wells from western (La Victoria) and eastern (San Joaquín) Venezuelan fields are studied. The DSA approach, together with rock magnetic experimental results, indicates that in the well from western Venezuela the main magnetic mineralogy associated to hydrocarbon microseepage is magnetite. Conversely, in the well from eastern Venezuela, these MS anomalies are mainly caused by the presence of Fe-sulphides (i.e. greigite). These results support the hypothesis of two different authigenic processes. For the well at the western field, we propose that a net electron transfer from the organic matter, degraded by hydrocarbon gas leakage, should occur precipitating Fe(II) magnetic minerals (e.g. magnetite). On the other hand, in the well of the eastern field, high concentrations of H2S at shallow levels, might allow the formation of secondary Fe-sulphides. Content Type Journal Article Pages 343-358 DOI 10.1007/s11200-011-0019-0 Authors Milagrosa Aldana, Dpto. Ciencias de la Tierra, Universidad Simón Bolívar, Caracas, Venezuela Vincenzo Costanzo-Álvarez, Dpto. Ciencias de la Tierra, Universidad Simón Bolívar, Caracas, Venezuela Luis Gómez, Coordinación de Ingeniería Geofísica, Universidad Simón Bolívar, Caracas, Venezuela Carlos González, Coordinación de Ingeniería Geofísica, Universidad Simón Bolívar, Caracas, Venezuela Marisel Díaz, Centro de Física, Instituto Venezolano de Investigaciones Científicas IVIC, Apartado 20632, Caracas, 1020A Venezuela Pedro Silva, Centro de Física, Instituto Venezolano de Investigaciones Científicas IVIC, Apartado 20632, Caracas, 1020A Venezuela Myriam Rada, Coordinación de Ingeniería Geofísica, Universidad Simón Bolívar, Caracas, Venezuela Journal Studia Geophysica et Geodaetica Online ISSN 1573-1626 Print ISSN 0039-3169 Journal Volume Volume 55 Journal Issue Volume 55, Number 2

Beschreibung:    For long time the western-central Mexico has been affected by oblique subduction caused by Farallon plate beneath North America. As result, smaller plates (e.g. Cocos Plate), several fault systems outlining crustal blocks (e.g. Michoacán block) and magmatic arcs (e.g. Paleocene-Early Oligocene magmatism and the Trans-Mexican Volcanic Belt) were developed. Still, no paleomagnetic data are available for Oligocene and Miocene. The principal aim of this study is to evaluate whether the tectonic rotations and relative motions of these blocks occurred before the Miocene. Here, we report a detailed rock-magnetic and paleomagnetic results from Tecalitlan area, located in the Michoacán block. Sixteen sites (about 150 oriented samples) were collected including one radiometrically dated diabase dike (35.0 ± 1.8 Ma). Rock-magnetic experiments permitted identification of magnetic carriers and assessment of the paleomagnetic stability. Continuous susceptibility measurements vs temperature in most cases yield reasonably reversible curves with Curie points close to that of magnetite. Reliable paleomagnetic directions were obtained for 12 sites. Inclination I and declination D of the mean paleomagnetic direction obtained in this study are I = 33.1°, D = 345.0°, and Fisherian statistical parameters are k = 25, α 95 = 8.9°. The corresponding mean paleomagnetic pole position is P lat = 75.7°, P long = 166.6°, K = 31, A 95 = 8.0°. The mean inclination is in reasonably good agreement with the expected value, as derived from reference poles for the stable North America. Magnetic declination is not significantly different from that expected which is in disagreement with a counterclockwise tectonic rotation of about 20° previously reported for the studied area. Based on paleomagnetic results obtained in this study compiled with those currently available from the Michoacán Block, we propose a simple model suggesting that sometime in Eocene epoch the convergence vector of the Farallon plate relative to North America plate was normal to the trench before reaching an actual oblique convergence. Content Type Journal Article Pages 265-278 DOI 10.1007/s11200-011-0015-4 Authors Jose Rosas-Elguera, Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Ingeniería Sísmica - Sede Guadalajara, CUCEI, Universidad de Guadalajara, 44840 Guadalajara, Mexico Bertha Aguilar Reyes, Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Geofísica - Sede Michoacán, Universidad Nacional Autónoma de México, Campus Morelia, 58089 Morelia, Mexico Avto Goguitchaichvili, Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Geofísica - Sede Michoacán, Universidad Nacional Autónoma de México, Campus Morelia, 58089 Morelia, Mexico Macario Rocha, Servicio Geológico Mexicano, Pachuca, Mexico Margarita López Martínez, Depto. de Geología, Centro de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana No. 3918, Apdo. Postal 60 Ensenada, B.C. México, Mexico Miriam M. Tostado-Plascencia, Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Ingeniería Sísmica - Sede Guadalajara, CUCEI, Universidad de Guadalajara, 44840 Guadalajara, Mexico Luis M. Alva Valdivia, Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México, Mexico Cecilia Caballero Miranda, Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México, Mexico Journal Studia Geophysica et Geodaetica Online ISSN 1573-1626 Print ISSN 0039-3169 Journal Volume Volume 55 Journal Issue Volume 55, Number 2

Beschreibung:    The paleosecular variation (PSV) and polarity transitions are two major features of the Earth’s magnetic field. Both PSV and reversal studies are limited when age of studied units is poorly constrained. This is a case of Central and western Mexico volcanics. Although many studies have been devoted to these crucial problems and more than 200 paleomagnetic directions are available for the last 5 Ma, only few sites were dated directly. This paper presents new paleomagnetic results from seventeen independent cooling units in the Michoacán-Guanajuato Volcanic Field (MGVF) in western Mexico. Twelve sites are directly dated by 40 Ar/ 39 Ar or K-Ar methods and span from 2.78 to 0.56 Ma. The characteristic paleodirections are successfully isolated for 15 lava flows. The mean paleodirection (inclination I and declination D) obtained in this study is I = 28.8°, D = 354.9°, and Fisherian statistical parameters are k = 28, α 95 = 7.3°, N=15, which corresponds to the mean paleomagnetic pole position P lat = 83.9°, P long = 321.6°, K = 34, A 95 = 6.6°. The paleodirections obtained in present study compiled with those, previously reported from the MGVF, are practically undistinguishable from the expected Plio-Quaternary paleodirections. The paleosecular variation is estimated through the study of the scatter of the virtual geomagnetic poles giving S F = 15.9 with S U =21.0 and S L = 12.7 (upper and lower limits respectively). These values agree reasonably well with the recent statistical Models. The oldest sites analyzed (the Santa Teresa and Cerro Alto) yield normal polarity magnetizations as expected for the cooling units belonging to the Gauss geomagnetic Chron. The interesting feature of the record comes from lava flows dated at about 2.35 Ma with clearly defined normal directions. This may point out the possible existence of a normal polarity magnetization in the Matuyama reversed Chron older than the Reunion and may be correlated to Halawa event interpreted as the Cryptochron C2r.2r-1. Another important feature of the geomagnetic record obtained from the MGVF is the evidence of fully reversed geomagnetic field within Bruhnes Chron, at about 0.56 Ma corresponding to the relative paleointensity minimum of global extent found in marine sediments at about 590 ka. Content Type Journal Article Pages 311-328 DOI 10.1007/s11200-011-0017-2 Authors Rafael Maciel Peña, Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Geofísica - Sede Michoacán, Universidad Nacional Autónoma de México, Campus Morelia, 58089 Morelia, Mexico Avto Goguitchaichvili, Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Geofísica - Sede Michoacán, Universidad Nacional Autónoma de México, Campus Morelia, 58089 Morelia, Mexico Bernard Henry, Paléomagnétisme, Institut de Physique du Globe de Paris and Centre National de la Recherche Scientifique, 94107 Saint Maur, France Leda Sánchez-Bettucci, Departamento de Geología, Area Geofísica-Geotectónica, Facultad de Ciencias, Universidad de la República, 11200 Montevideo, Uruguay Juan Morales, Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Geofísica - Sede Michoacán, Universidad Nacional Autónoma de México, Campus Morelia, 58089 Morelia, Mexico Bertha Aguilar Reyes, Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Geofísica - Sede Michoacán, Universidad Nacional Autónoma de México, Campus Morelia, 58089 Morelia, Mexico Ana María Soler-Arechalde, Laboratorio de Paleomagnétismo, Instituto de Geofísica, Universidad Nacional Autónoma de México, 04510 México DF., México Manuel Calvo-Rathert, Laboratorio de Paleomagnetismo, Departamento de Física, Escuela Politécnica Superior, Universidad de Burgos, C/Francisco de Vitoria, s/n, 09006 Burgos, Spain Journal Studia Geophysica et Geodaetica Online ISSN 1573-1626 Print ISSN 0039-3169 Journal Volume Volume 55 Journal Issue Volume 55, Number 2

Beschreibung:    A major challenge in using GPS guidance for aircraft final approach and landing is to reject interference that can jam reception of the GPS signals. Antenna arrays, which use space–time adaptive processing (STAP), significantly improve the signal to interference plus noise ratio, but at the possible expense of distorting the received signals, leading to timing biases that may degrade navigation performance. Rather than a sophisticated calibration approach to remove biases introduced by STAP, this paper demonstrates that a relatively compact calibration strategy can substantially reduce navigation biases, even under elevated interference conditions. Consequently, this paper develops an antenna bias calibration strategy for two classes of adaptive array algorithm and validates this method using both simulated and experimental data with operational hardware in the loop. A proof-of-concept system and an operational prototype are described, which implement the adaptive antenna algorithms and deterministic corrections. This investigation demonstrates that systems with adaptive antenna arrays can approach the accuracy and integrity requirements for automatic aircraft landing, and in particular for sea-based landing on board aircraft carriers, while simultaneously providing significant attenuation of interference. Evidence suggests that achieving these goals is possible with minimal restrictions on system hardware configuration—specifically, limitations on the permissible level of antenna anisotropy and the use of sufficient analog-to-digital converter resolution. Content Type Journal Article Pages 1-10 DOI 10.1007/s10291-011-0224-x Authors David S. De Lorenzo, GPS Research Laboratory, Department of Aeronautics and Astronautics, Stanford University, Durand Building, Room 452, Stanford, CA 94305-4035, USA Sherman C. Lo, GPS Research Laboratory, Department of Aeronautics and Astronautics, Stanford University, Durand Building, Room 452, Stanford, CA 94305-4035, USA Per K. Enge, GPS Research Laboratory, Department of Aeronautics and Astronautics, Stanford University, Durand Building, Room 452, Stanford, CA 94305-4035, USA Jason Rife, Automated Systems and Robotics Laboratory, Department of Mechanical Engineering, Tufts University, 024 Anderson Hall, Medford, MA 02115, USA Journal GPS Solutions Online ISSN 1521-1886 Print ISSN 1080-5370

Beschreibung:    The world of global navigation satellite systems has been enhanced with several new or improved signals in space aiming to optimize accuracy, reliability, navigation solution, and interoperability between different constellations. However, such developments bring various challenges to the receivers’ designers. For example, acquisition and tracking stages turn into more complex processes while handling the increasing bandwidth requires additional processing power. In this context, we study the code tracking of Galileo E5ab in a full band or of only one of its components, i.e., either E5a or E5b. More specifically, an architecture for tracking the E5 pilot channel as an AltBOC(15,10) or BPSK(10) modulation is introduced, and the performance of well-known discriminator types is analyzed using analytical derivations and simulations of linearity and stability regions, thermal noise tracking errors, multipath error envelopes and tracking thresholds. Different parameters, such as the front-end filter bandwidth, the early/late chip spacing, un-normalized and normalized discriminators, are taken into consideration. The results obtained are used to illustrate the main advantages and drawbacks of tracking the E5 signal as well as to help defining the main tracking loop parameters for an enhanced performance. Content Type Journal Article Pages 1-16 DOI 10.1007/s10291-011-0226-8 Authors Youssef Tawk, Institute of Microengineering (IMT) Electronics and Signal Processing Laboratory, Ecole Polytechnique Fédérale de Lausanne, Breguet 2, 2000 Neuchâtel, Switzerland Cyril Botteron, Institute of Microengineering (IMT) Electronics and Signal Processing Laboratory, Ecole Polytechnique Fédérale de Lausanne, Breguet 2, 2000 Neuchâtel, Switzerland Aleksandar Jovanovic, Institute of Microengineering (IMT) Electronics and Signal Processing Laboratory, Ecole Polytechnique Fédérale de Lausanne, Breguet 2, 2000 Neuchâtel, Switzerland Pierre-André Farine, Institute of Microengineering (IMT) Electronics and Signal Processing Laboratory, Ecole Polytechnique Fédérale de Lausanne, Breguet 2, 2000 Neuchâtel, Switzerland Journal GPS Solutions Online ISSN 1521-1886 Print ISSN 1080-5370

Beschreibung:    This research is motivated by the recent IGS Ionosphere Working Group recommendation issued at the IGS 2010 Workshop held in Newcastle, UK. This recommendation encourages studies on the evaluation of the application of COSMIC radio occultation profiles for additional IGS global ionosphere map (GIM) validation. This is because the reliability of GIMs is crucial to many geodetic applications. On the other hand, radio occultation using GPS signals has been proven to be a promising technique to retrieve accurate profiles of the ionospheric electron density with high vertical resolution on a global scale. However, systematic validation work is still needed before using this powerful technique for sounding the ionosphere on a routine basis. In this paper, we analyze the properties of the ionospheric electron density profiling retrieved from COSMIC radio occultation measurements. A comparison of radio occultation data with ground-based measurements indicates that COSMIC profiles are usually in good agreement with ionosonde profiles, both in the F2 layer peak electron density and the bottom side of the profiles. For this comparison, ionograms recorded by European ionospheric stations (DIAS network) in 2008 were used. Content Type Journal Article Pages 1-16 DOI 10.1007/s00190-011-0481-z Authors Andrzej Krankowski, Geodynamics Research Laboratory, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland Irina Zakharenkova, Geodynamics Research Laboratory, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland Anna Krypiak-Gregorczyk, Geodynamics Research Laboratory, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland Irk I. Shagimuratov, West Department of IZMIRAN, Kaliningrad, Russia Pawel Wielgosz, Geodynamics Research Laboratory, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    In preparation of activities planned for the realization of the Global Geodetic Observing System (GGOS), a group of German scientists has carried out a study under the acronym GGOS-D which closely resembles the ideas behind the GGOS initiative. The objective of the GGOS-D project was the investigation of the methodological and information-technological realization of a global geodetic-geophysical observing system and especially the integration and combination of the space geodetic observations. In the course of this project, highly consistent time series of GPS, VLBI, and SLR results were generated based on common state-of-the-art standards for modeling and parameterization. These series were then combined to consistently and accurately compute a Terrestrial Reference Frame (TRF). This TRF was subsequently used as the basis to produce time series of station coordinates, Earth orientation, and troposphere parameters. In this publication, we present results of processing algorithms and strategies for the integration of the space-geodetic observations which had been developed in the project GGOS-D serving as a prototype or a small and limited version of the data handling and processing part of a global geodetic observing system. From a comparison of the GGOS-D terrestrial reference frame results and the ITRF2005, the accuracy of the datum parameters is about 5–7 mm for the positions and 1.0–1.5 mm/year for the rates. The residuals of the station positions are about 3 mm and between 0.5 and 1.0 mm/year for the station velocities. Applying the GGOS-D TRF, the offset of the polar motion time series from GPS and VLBI is reduced to 50 μ as (equivalent to 1.5 mm at the Earth’s surface). With respect to troposphere parameter time series, the offset of the estimates of total zenith delays from co-located VLBI and GPS observations for most stations in this study is smaller than 1.5 mm. The combined polar motion components show a significantly better WRMS agreement with the IERS 05C04 series (96.0/96.0  μ as) than VLBI (109.0/100.7  μ as) or GPS (98.0/99.5  μ as) alone. The time series of the estimated parameters have not yet been combined and exploited to the extent that would be possible. However, the results presented here demonstrate that the experiences made by the GGOS-D project are very valuable for similar developments on an international level as part of the GGOS development. Content Type Journal Article Pages 1-27 DOI 10.1007/s00190-011-0475-x Authors M. Rothacher, Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum, Telegrafenberg A17, 14473 Potsdam, Germany D. Angermann, Deutsches Geodätisches Forschungsinstitut, Alfons-Goppel-Straße 11, 80539 Munich, Germany T. Artz, Institute of Geodesy and Geoinformation, University of Bonn, Nussallee 17, 53115 Bonn, Germany W. Bosch, Deutsches Geodätisches Forschungsinstitut, Alfons-Goppel-Straße 11, 80539 Munich, Germany H. Drewes, Deutsches Geodätisches Forschungsinstitut, Alfons-Goppel-Straße 11, 80539 Munich, Germany M. Gerstl, Deutsches Geodätisches Forschungsinstitut, Alfons-Goppel-Straße 11, 80539 Munich, Germany R. Kelm, Deutsches Geodätisches Forschungsinstitut, Alfons-Goppel-Straße 11, 80539 Munich, Germany D. König, Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum, Telegrafenberg A17, 14473 Potsdam, Germany R. König, Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum, Telegrafenberg A17, 14473 Potsdam, Germany B. Meisel, Deutsches Geodätisches Forschungsinstitut, Alfons-Goppel-Straße 11, 80539 Munich, Germany H. Müller, Deutsches Geodätisches Forschungsinstitut, Alfons-Goppel-Straße 11, 80539 Munich, Germany A. Nothnagel, Institute of Geodesy and Geoinformation, University of Bonn, Nussallee 17, 53115 Bonn, Germany N. Panafidina, Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum, Telegrafenberg A17, 14473 Potsdam, Germany B. Richter, Bundesamt für Kartographie und Geodäsie, Richard-Strauss-Allee 11, 60598 Frankfurt am Main, Germany S. Rudenko, Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum, Telegrafenberg A17, 14473 Potsdam, Germany W. Schwegmann, Bundesamt für Kartographie und Geodäsie, Richard-Strauss-Allee 11, 60598 Frankfurt am Main, Germany M. Seitz, Deutsches Geodätisches Forschungsinstitut, Alfons-Goppel-Straße 11, 80539 Munich, Germany P. Steigenberger, Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum, Telegrafenberg A17, 14473 Potsdam, Germany S. Tesmer, Institute of Geodesy and Geoinformation, University of Bonn, Nussallee 17, 53115 Bonn, Germany V. Tesmer, Deutsches Geodätisches Forschungsinstitut, Alfons-Goppel-Straße 11, 80539 Munich, Germany D. Thaller, Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum, Telegrafenberg A17, 14473 Potsdam, Germany Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung: A Brief Jacobsean Take on German Cities in Europe Through the Last Millennium Content Type Journal Article Pages 1-2 DOI 10.1007/s13147-011-0096-0 Authors Peter J. Taylor, School of Built and Natural Environment, Northumbria University, NE1, 8ST Newcastle upon Tyne, UK Journal Raumforschung und Raumordnung Online ISSN 1869-4179 Print ISSN 0034-0111

Beschreibung:    Satellite survey techniques have become commonplace for several applications such as surveying, environmental positioning, and navigation. The possibility of using this technique is strongly dependent on the possibility of receiving data from at least four satellites, as the accuracy is dependent on both the number of visible satellites and on their relative positions in the sky. From a theoretical standpoint, the Global Positioning System (GPS) constellation of satellites was designed to guarantee the continuous visibility of a minimum of four satellites worldwide, but this was based on the major approximation of considering the earth as an ellipsoid. The presence of natural (such as mountains) and anthropic (such as buildings) obstacles reduce sky visibility, in some cases significantly, thereby reducing the position accuracy or the possibility of determining a position (in the case of less than four satellites). The evolution of satellite positioning technologies will result in the possibility that, in the near future, many constellations can be used to determine the position of a receiver. Additionally, the Glonass constellation will be improved, and the new Galileo constellation will be deployed. Starting from digital elevation models (DEM), orbits (broadcast or precise), and the Keplerian parameters of new constellations, an open-source software has been realized with the aim of performing more accurate planning and simulations of the skyplot (the map of the visible satellites) in a point or region for a defined window of time. The software, developed in the C++ language, permits the simulation of the current constellation and the simulation of future scenarios by considering the interoperability between NAVSTAR-GPS, GLONASS, Galileo, COMPASS, and other systems. The simulation, conducted using DEM, permits the definition of a more correct obstacle map for each point. Of course, the DEM is more detailed and accurate, resulting in a more precise obstacle map and thus a more precise simulation (DEMs derived from Lidar data can even be used to account for the blockage caused by buildings). This paper begins with an introduction concerning the approach used to determine the skyplot and the obstacle map derived from a DEM, continues by explaining the logical architecture of the software and then presents simulation results in different conditions (with or without the DEM, using different constellations, and considering either one point or a regional analysis). Content Type Journal Article Pages 1-14 DOI 10.1007/s12518-011-0045-1 Authors Stefano Gandolfi, Engineering Faculty, DICAM-ARCES, University of Bologna, Bologna, Italy Luca La Via, Engineering Faculty, DICAM-ARCES, University of Bologna, Bologna, Italy Journal Applied Geomatics Online ISSN 1866-928X Print ISSN 1866-9298

Beschreibung:    This paper reports preliminary findings of a study in northern Viti Levu Island (Fiji) intended to test the model of the AD 1300 Event. This holds that around AD 1250–1350, during the transition between the Medieval Warm Period and the Little Ice Age, there was a rapid climate-driven sea-level fall of 70–80 cm which created a food crisis for coastal dwellers throughout the tropical Pacific Islands and led to conflict and the abandonment of open coastal settlements in favour of those in more defensible locations. Two main areas were targeted—the Ba River Valley and adjoining Vatia Peninsula (plus offshore islands)—and inland/offshore sites in defensible locations, particularly in caves, ridge-top rockshelters, and isolated hilltops, were surveyed and test excavations made. Results show that while some of these sites were established during the AD 1300 Event, most were established shortly afterwards, which is exactly what the model predicts. It is concluded that prehistoric populations in Fiji (and similar island groups) were affected by the food crisis during the AD 1300 Event and did respond in ways that profoundly and enduringly altered contemporary trajectories of societal evolution. This study has great implications for the preservation of the record of prehistoric settlement in Fiji (and other tropical Pacific Island groups) because, as a consequence of this climate-forced migration from coasts to inland/upland sites, large amounts of sediment were released from island interiors and carried to their coasts where they buried earlier settlements or redistributed their material signature. Since European arrival in such places around 150 years ago, a second wave of coastal sedimentation, largely driven by plantation agriculture development had similar effects. The current rise of sea level around Pacific Island coasts is the latest in a series of (largely human) threats to the preservation of their cultural heritage. Content Type Journal Article Pages 1-11 DOI 10.1007/s11852-010-0142-z Authors Patrick D. Nunn, School of Behavioural, Cognitive and Social Sciences, The University of New England, Armidale, NSW 2351, Australia Journal Journal of Coastal Conservation Online ISSN 1874-7841 Print ISSN 1400-0350

Beschreibung:    Previous studies have found a higher proportion of alien plant species along the coastal area of the Black Sea. The goals of the present study were to assess the role of two harbours as gateways and reservoirs for alien plant species, to compare the structure and invasion pattern of the alien plants recorded there, and test methods useful for effective monitoring programs. We inventoried 12 sites along the western Black Sea coast from the harbour of Sulina in the north to Cape Kaliakra in the south. Each site was visited at least three times each. A more intensive survey was done in the two harbours targeted by our study: Constanţa and Sulina. The proportion of neophytes was higher in the harbours (representing about one third of the total plant species) and lower in coastal protected areas (with an average proportion of 6.7%). Species accumulation curves and estimators of species richness indicated that while the plant inventory was not complete, invasive alien species (IAS) were adequately inventoried. Harbours act not only as gateways for IAS but also as reservoirs, facilitating their acclimatization and naturalization. The use of species accumulation curves and estimators of species richness are useful tools in designing and evaluating simple monitoring programs based on repeated inventories. Our study has stressed the importance of monitoring not only coastal waters but also green areas in harbours for the early detection of IAS. Content Type Journal Article Pages 1-12 DOI 10.1007/s11852-011-0149-0 Authors Paulina Anastasiu, Faculty of Biology, Department of Botany and Microbiology, University of Bucharest, 1-3 Intr. Portocalelor, 060101 Bucureşti, România Gavril Negrean, Faculty of Biology, Department of Botany and Microbiology, University of Bucharest, 1-3 Intr. Portocalelor, 060101 Bucureşti, România Ciprian Samoilă, Faculty of Natural and Agricultural Sciences, “Ovidius” University of Constanţa, 1 Aleea Universităţii, 900470 Constanţa, România Daniyar Memedemin, Faculty of Natural and Agricultural Sciences, “Ovidius” University of Constanţa, 1 Aleea Universităţii, 900470 Constanţa, România Dan Cogălniceanu, Faculty of Natural and Agricultural Sciences, “Ovidius” University of Constanţa, 1 Aleea Universităţii, 900470 Constanţa, România Journal Journal of Coastal Conservation Online ISSN 1874-7841 Print ISSN 1400-0350

Beschreibung:    Lake Peipsi is of great economic significance, first of all, in terms of water transport, fishery and energy production. Its bottom deposits hold great reserves of curative mud and building materials, and its waters cool the huge kettles of the Baltic and Estonian Thermal Power Plants and drive the turbines of the Narva Hydropower Station. The beaches of the lake, especially in the northern and eastern parts, have a high recreational value. The lake is shared between Estonia and Russia. The sparsely distributed population is mainly engaged in fishery and agriculture. Long-term observations have shown that the water level in L. Peipsi fluctuates greatly. This complicates water transport, shore protection and recreational possibilities around the lake. Both, water erosion and hummocky ice have changed the coasts, but differently in every year. Due to the uneven glacioisostatic uplift of the lake basin the water masses are steadily retreating southward, which means that in the coming future erosion of the northern coast will diminish and large areas on the southern coast will be flooded. Sustainable development of L. Peipsi integrates social, economic, cultural and environmental concerns. Recommendations for the protection and management of the coastal zone are presented. Content Type Journal Article Pages 1-7 DOI 10.1007/s11852-010-0143-y Authors Anto Raukas, Institute of Ecology at Tallinn University, Uus-Sadama 5, Tallinn, 10120 Estonia Elvi Tavast, Institute of Geology at Tallinn University of Technology, Ehitajate tee 5, Tallinn, 19086 Estonia Journal Journal of Coastal Conservation Online ISSN 1874-7841 Print ISSN 1400-0350

Beschreibung:    This paper presents a generalization algorithm focusing specifically on urban street networks. A street map that uses outlines of blocks to implicitly delineate the shape of streets is essentially a complex polygon with holes in computer graphics. Given such a street map, this algorithm first applies medial axis transformation to derive a rudimentary skeleton of the street network. Because the resulting medial axes tend to exaggeratedly reflect even a minor change in the street shapes, the rudimentary skeleton must undergo a generalization process to become a representation that does not simply resemble the street shapes but is actually informative for understanding its deeper structure. Instead of discarding the street shapes and using only cartographic generalization techniques to simplify the skeleton, the algorithm uses the medial axes as the guide to partition the shape of the streets into individual convex spaces. These initial convex spaces are then successively merged into larger convex spaces following the line-of-sight and least-angle-change principles until the least set of convex space has been achieved. Next, the algorithm uses the same line-of-sight and least-angle-change principles to successively group convex spaces into mutually exclusive convex-space sets until no further grouping can occur. Finally, original medial axes inside each final convex-space set are replaced with a straight-line segment. Collectively, these new line segments form a generalized street network representation that is more favorable in network theory. This new algorithm points out an improved and likely automatic solution of generating appropriate street network representations for spatial configuration analyses of the urban environment. Content Type Journal Article Pages 1-8 DOI 10.1007/s12518-011-0049-x Authors Wen-Chieh (Jeffrey) Wang, Department of Landscape and Urban Design, Chaoyang University of Technology, 168 Jifeng East Road, Wufeng District, Taichung, 41349 Taiwan, Republic of China Journal Applied Geomatics Online ISSN 1866-928X Print ISSN 1866-9298

Beschreibung:    The ionosphere is a dispersive medium for microwaves, and most space-geodetic techniques using two or more signal frequencies can be applied to extract information on ionospheric parameters, including terrestrial as well as satellite-based GNSS, DORIS, altimetry, and VLBI. Because of their different sensitivity regarding ionization, their different spatial and temporal data distribution, and their different signal paths, a joint analysis of all observation types seems reasonable and promises the best results for ionosphere modeling. However, it has turned out that there exist offsets between ionospheric observations of the diverse techniques mainly caused by calibration uncertainties or model errors. Direct comparisons of the information from different data types are difficult because of the inhomogeneous measurement epochs and locations. In the approach presented here, all measurements are combined into one ionosphere model of vertical total electron content (VTEC). A variance component estimation is applied to take into account the different accuracy levels of the observations. In order to consider systematic offsets, a constant bias term is allowed for each observation group. The investigations have been performed for the time interval of the CONT08 campaign (2 weeks in August 2008) in a region around the Hawaiian Islands. Almost all analyzed observation techniques show good data sensitivity and are suitable for VTEC modeling in case the systematic offsets which can reach up to 5 TECU are taken into account. Only the Envisat DORIS data cannot provide reliable results. Content Type Journal Article Pages 1-9 DOI 10.1007/s00190-011-0473-z Authors Denise Dettmering, Deutsches Geodätisches Forschungsinstitut (DGFI), Alfons-Goppel-Strasse 11, 80539 Munich, Germany Robert Heinkelmann, Deutsches Geodätisches Forschungsinstitut (DGFI), Alfons-Goppel-Strasse 11, 80539 Munich, Germany Michael Schmidt, Deutsches Geodätisches Forschungsinstitut (DGFI), Alfons-Goppel-Strasse 11, 80539 Munich, Germany Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    In den Jahren 1996, 2005 und zuletzt 2010 traten wichtige Änderungen des Wasserhaushaltsgesetzes in Kraft. Diese hatten jeweils zum Ziel, das wasserwirtschaftliche Planungsinstrumentarium zu stärken, um den Flüssen mehr Raum zu geben. Doch wie wirken diese rechtlichen Änderungen in der Praxis? Der vorliegende Beitrag untersucht dies mit Hilfe einer Politikfeldanalyse am Beispiel der Hochwasserkonzeption des Landes Sachsen-Anhalt. Diese Konzeption wurde erstmals 2003 mit dem Zielhorizont 2010 aufgestellt. Zwei Zeiträume werden betrachtet: vor und nach dem Inkrafttreten des Hochwasserschutzgesetzes 2005. Es wird gezeigt, dass die rechtlichen Änderungen nicht auf die Umsetzungsrestriktionen der Praxis antworten. Die Schwierigkeiten in der Praxis bestehen in erster Linie in den Bereichen, in denen andere Akteure als die Wasserwirtschaft – also etwa die Raumordnung, die Bauleitplanung oder Bodeneigentümer – eine wichtige Rolle bei der Umsetzung der wasserwirtschaftlichen Ziele einnehmen. Der Gesetzgeber folgt bei der Realisierung des räumlichen Hochwasserschutzes (Raum für die Flüsse) einem Kontrollparadigma: Es wird stets versucht, die Instrumente der Wasserwirtschaft zu stärken. Die tatsächlichen Praxisprobleme erfordern jedoch Instrumente, die integrative Planungsprozesse ermöglichen, um Konflikte mit räumlichem Hochwasserschutz zu begegnen und auf ein Umdenken in der Wasserwirtschaft hinzuwirken – von einer kontrollierenden zu einer integrativen Form von Governance . Integrativ bedeutet hier die frühzeitige und aktive Einbindung relevanter Stakeholder in die Planungsprozesse. Content Type Journal Article Pages 1-12 DOI 10.1007/s13147-011-0091-5 Authors Thomas Hartmann, Faculty of Geosciences, Department of Human Geography and Planning, Utrecht University, PO-Box 80 115, 3508 TC Utrecht, The Netherlands Journal Raumforschung und Raumordnung Online ISSN 1869-4179 Print ISSN 0034-0111

Beschreibung:    Greenland ice mass loss is one of the most serious phenomena of present-day global climate change. In this context, both the quantification of overall deglaciation rates and its spatial localization are highly significant. We have thoroughly investigated the technique of point-mass modeling in order to derive mass-balance patterns from GRACE (Gravity Recovery And Climate Experiment) gravimetry. The method infers mass variations on the Earth’s surface from gravitational signals at satellite altitude. In order to solve for point-mass changes, we applied least-squares adjustment. Due to downward continuation, numerical stabilization of the inversion process gains particular significance. We stabilized the ill-posed problem by Tikhonov regularization. Our simulation and real data experiments show that point-mass modeling provides both rational deglaciation rates and high-resolution spatial mass variation patterns. Content Type Journal Article Pages 1-9 DOI 10.1007/s00190-011-0463-1 Authors Oliver Baur, Institute of Geodesy, University of Stuttgart, Geschwister-Scholl-Str. 24D, 70174 Stuttgart, Germany Nico Sneeuw, Institute of Geodesy, University of Stuttgart, Geschwister-Scholl-Str. 24D, 70174 Stuttgart, Germany Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    The most crucial part of the GOCE gradiometer processing is, besides the internal calibration of the gradiometer, the determination of the satellite’s inertial angular rate. This paper describes a new method for the angular rate determination. It is based on the stochastic properties of the GOCE star sensors and the gradiometer. The attitude information of both instrument types is combined at the level of angular rates. The combination is done in the spectral domain by Wiener filtering, and thus using an optimal relative weighting of the star sensor and gradiometer attitude information. Since the complete processing chain from raw measurements to gravity field solutions is performed, the results are not only analyzed at the level of gravity gradients, but also of gravity field solutions. Compared to the nominal method, already the resulting gravity gradients show a significantly improved performance for the frequencies (mainly) below the gradiometer measurement bandwidth. This can be verified by analysis of the gravity gradient trace. The improvement is propagated to the level of gravity field models, where a better accuracy can be observed for selected groups of coefficients at characteristic bands at orders k  × 16, with integer k , up to high harmonic degrees. Content Type Journal Article Pages 1-12 DOI 10.1007/s00190-011-0461-3 Authors C. Stummer, Institut für Astronomische und Physikalische Geodäsie (IAPG), Technische Universität München, Arcisstr. 21, 80290 Munich, Germany T. Fecher, Institut für Astronomische und Physikalische Geodäsie (IAPG), Technische Universität München, Arcisstr. 21, 80290 Munich, Germany R. Pail, Institut für Astronomische und Physikalische Geodäsie (IAPG), Technische Universität München, Arcisstr. 21, 80290 Munich, Germany Journal Journal of Geodesy Online ISSN 1432-1394 Print ISSN 0949-7714

Beschreibung:    Die wachsende Zahl älterer Menschen in den Kommunen führt zu der Notwendigkeit, die Planung für diese Zielgruppe anzupassen und so die Voraussetzungen zur Erhaltung von Lebensqualität zu schaffen. Um die Planungen für ältere Menschen in der rheinland-pfälzischen Stadt Pirmasens zu unterstützen, wurden im Rahmen eines Projektes neben einer repräsentativen Seniorenbefragung und Experteninterviews sechs Zukunftswerkstätten in unterschiedlichen Stadtteilen durchgeführt. In diesem Aufsatz wird aufgezeigt, inwieweit Zukunftswerkstätten ein geeignetes Instrument darstellen, um einerseits Wünsche und Bedürfnisse zu ermitteln und andererseits ältere Menschen anzuregen, sich selbst für die Umsetzung ihrer geäußerten Anliegen zu engagieren. Content Type Journal Article Pages 1-10 DOI 10.1007/s13147-011-0083-5 Authors Pia Gerhards, Lehrgebiet Stadtsoziologie, Technische Universität Kaiserslautern, Pfaffenbergstraße 95, 67663 Kaiserslautern, Deutschland Annette Spellerberg, Lehrgebiet Stadtsoziologie, Technische Universität Kaiserslautern, Pfaffenbergstraße 95, 67663 Kaiserslautern, Deutschland Journal Raumforschung und Raumordnung Online ISSN 1869-4179 Print ISSN 0034-0111

Beschreibung: Klemme, Marion; Selle, Klaus (Hrsg.) (2010): Siedlungsflächen entwickeln. Akteure. Interdependenzen. Optionen Content Type Journal Article Pages 1-2 DOI 10.1007/s13147-011-0084-4 Authors Theo Kötter, Professur für Städtebau und Bodenordnung, Rheinische Friedrich-Wilhelms-Universität Bonn, Nussallee 1, 53115 Bonn, Deutschland Journal Raumforschung und Raumordnung Online ISSN 1869-4179 Print ISSN 0034-0111