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Frankfurt am Main, Germany

Velikoseltsev A.,Saint Petersburg Electrotechnical University | Schreiber K.U.,Bundesamt fur Kartographie und Geodasie | Yankovsky A.,Di Mendeleyev Institute For Metrology | Wells J.-P.R.,University of Canterbury | And 2 more authors.
Journal of Seismology

In recent years, the measurement of rotational components of earthquake-induced ground motion became a reality due to high-resolution ring laser gyroscopes. As a consequence of the fact that they exploit the Sagnac effect, these devices are entirely insensitive to translational motion and are able to measure the rotation rate with high linearity and accuracy over a wide frequency band. During the last decade, a substantial number of earthquakes were recorded by the large ring lasers located in Germany, New Zealand, and USA, and the subsequent data analysis demonstrated reliability and consistency of the results with respect to theoretical models. However, most of the observations recorded teleseismic events in the far-field. The substantial mass and the size of these active interferometers make their near-field application difficult. Therefore, the passive counterparts of ring lasers, the fiber optic gyros can be used for seismic applications where the mobility is more important than extreme precision. These sensors provide reasonable accuracy and are small in size, which makes them perfect candidates for strong motion applications. The other advantage of fiber optic gyroscopes is that if the earthquake is local and shallow (like one occurred early this year at Canterbury, New Zealand), the large ring lasers simply do not have the dynamic range-the effect is far too large for these instruments. In this paper, we analyze a typical commercially available tactical grade fiber optic gyroscope (VG-951) with respect to the seismic rotation measurement requirements. The initial test results including translation and upper bounds of seismic rotation sensitivity are presented. The advantages and limitations of tactical grade fiber optic gyroscope as seismic rotation sensor are discussed. © 2012 Springer Science+Business Media B.V. Source

Heiker A.,Leibniz University of Hanover | Kutterer H.,Bundesamt fur Kartographie und Geodasie
International Association of Geodesy Symposia

Models are often treated as deterministic in geodetic practice. Hence, inaccurate models directly affect the results of geodetic measurements. This paper proposes a method for the mutual validation of models and observed data. To consider the inaccuracy of models, data resulting from models are treated as stochastic parameter in a linear least squares adjustment. The required stochastic information is obtained by empirical auto and cross correlation functions. This approach is applied to the problem of the mutual validation of Earth orientation parameters, second degree gravity field coefficients and geophysical excitation functions. The results and the limitations of this approach are discussed. © Springer International Publishing Switzerland 2015. Source

Schreiber K.U.,TU Munich | Klugel T.,Bundesamt fur Kartographie und Geodasie | Wells J.-P.R.,University of Canterbury | Hurst R.B.,University of Canterbury | Gebauer A.,TU Munich
Physical Review Letters

We demonstrate a 16m2 helium-neon ring laser gyroscope with sufficient sensitivity and stability to directly detect the Chandler wobble of the rotating Earth. The successful detection of both the Chandler and the annual wobble is verified by comparing the time series of the ring laser measurements against the "C04 series" of Earth rotation data from the International Earth Rotation and Reference System Service. © 2011 American Physical Society. Source

Illert A.,Bundesamt fur Kartographie und Geodasie
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives

The environmental sector in the European Union has taken the lead in an initiative called INSPIRE that aims at creating the framework for the European Spatial Data Infrastructure (ESDI). With INSPIRE it shall be possible to combine spatial data from different sources in the National Spatial Data Infrastructures (NSDI) across the Community in a consistent way and share them between several users and applications. INSPIRE legislation is legally binding on all authorities in the EU member states. From a technical point of view, INSPIRE shall achieve the interoperability of spatial data sets by means of network services. The client of such services shall be enabled to discover, view and download spatial data sets in conformance with harmonised European specifications. INSPIRE promotes conceptual modeling and mandates formal modeling languages such as UML and GML. The domain experts need to find a balance between advanced concepts and traditional but well established patterns, while the proposed solutions should not result in excessive costs for the data providers. Source

Montenbruck O.,German Space Operations Center | Hauschild A.,German Space Operations Center | Hessels U.,Bundesamt fur Kartographie und Geodasie
GPS Solutions

The Cooperative Network for GIOVE Observation (CONGO) is a global network of real-time capable multi-constellation GNSS receivers, which has been established by the German Aerospace Center (DLR) and the German Federal Agency for Cartography and Geodesy (BKG) as a test bed for experimentation with the new Galileo signals. The CONGO network employs a variety of different antennas and receivers which have become available for public use over the last 2 years. Following an overview of the network and the employed user equipment, the paper discusses the achieved GPS/GIOVE tracking performance. This includes a characterization of antenna gain patterns as well as receiver noise and multipath errors. Special attention is given to the discussion of inter-system biases. The nature and variation of these biases is illustrated based on a set of three different receivers operated in a zero-baseline configuration at the Wettzell site. © 2010 Springer-Verlag. Source

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