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Systematic biases in DORIS-derived geocenter time series related to solar radiation pressure mis-modeling 总被引：2，自引：1，他引：1
M. L. Gobinddass P. Willis O. de Viron A. Sibthorpe N. P. Zelensky J. C. Ries R. Ferland Y. Bar-Sever M. Diament 《Journal of Geodesy》2009,83(9):849-858
As any satellite geodesy technique, DORIS can monitor geocenter variations associated to mass changes within the Earth–Atmosphere–Continental
hydrosphere–Oceans system. However, especially for the Z-component, corresponding to a translation of the Earth along its rotation axis, the estimated geocenter is usually affected
by large systematic errors of unknown cause. By reprocessing old DORIS data, and by analyzing single satellite solutions in
the frequency domain, we show that some of these errors are satellite-dependent and related to the current DORIS orbit determination
strategy. In particular, a better handling of solar pressure radiation effects on SPOT-2 and TOPEX satellites is proposed
which removes a large part of such artifacts. By empirically multiplying the current solar pressure model with a single coefficient
(1.03 for TOPEX/Poseidon after 1993.57, and 0.96 before; and 1.08 for SPOT-2) estimated over a long time period, we can improve
the measurement noise of the Z-geocenter component from 47.5 to 30.4 mm for the RMS and from 35 to 6 mm for the amplitude of the annual signal. However,
the estimated SRP coefficient for SPOT-2 presents greater temporal variability, indicating that a new, dedicated solar radiation
pressure model is still needed for precise geodetic applications. In addition, for the TOPEX satellite, a clear discontinuity
of unknown cause is also detected on July 27, 1993. 相似文献
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GPS-assisted GLONASS orbit determination 总被引：1，自引：0，他引：1
D. Kuang Y. E. Bar-Sever W. I. Bertiger K. J. Hurst J. F. Zumberge 《Journal of Geodesy》2001,75(11):569-574
Using 1 week of data from a network of GPS/GLONASS dual-tracking receivers, 15-cm accurate GLONASS orbit determination is
demonstrated with an approach that combines GPS and GLONASS data. GPS data are used to define the reference frame, synchronize
receiver clocks and determine troposphere delay for the GLONASS tracking network. GLONASS tracking data are then processed
separately, with the GPS-defined parameters held fixed, to determine the GLONASS orbit. The quality of the GLONASS orbit determination
is currently limited by the size and distribution of the tracking network, and by the unavailability of a sufficiently refined
solar pressure model. Temporal variations in the differential clock bias of the dual-tracking receivers are found to have
secondary impact on the orbit determination accuracy.
Received: 5 January 2000 / Accepted: 15 February 2001 相似文献
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A new model for GPS yaw attitude 总被引：7，自引：4，他引：3
Yoaz E. Bar-Sever 《Journal of Geodesy》1996,70(11):714-723
modeling of the GPS satellite yaw attitude is a key element in high-precision geophysical applications. This fact is illustrated here as a new model for the GPS satellite yaw attitude is introduced. The model constitutes a significant improvement over the previously available model in terms of efficiency, flexibility and portability. The model is described in detail and implementation issues, including the proper estimation strategy, are addressed. The performance of the new model is analyzed and an error budget is presented. Finally, the implementation of the yaw bias on the GPS satellites is reviewed from its inception until it reached a steady state in November, 1995. 相似文献
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Bruce Haines Yoaz Bar-Sever Willy Bertiger Shailen Desai Pascal Willis 《Marine Geodesy》2004,27(1):299-318
The U.S./French Jason-1 satellite is carrying a state-of-the-art GPS receiver to support precise orbit determination (POD) requirements. The performance of the Jason-1 “BlackJack” GPS receiver was strongly reflected in early POD results from the mission, enabling radial accuracies of 1-2 cm soon after the satellite's 2001 launch. We have made further advances in the GPS-based POD for Jason-1, most notably in describing the phase center variations of the on-board GPS antenna. We have also adopted new geopotential models from the Gravity Recovery and Climate Experiment (GRACE). The new strategies have enabled us to better exploit the unique contributions of the BlackJack GPS tracking data in the POD process. Results of both internal and external (e.g., laser ranging) comparisons indicate that orbit accuracies of 1 cm (radial RMS) are being achieved for Jason-1 using GPS data alone. 相似文献
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A new type of troposphere zenith path delay product of the international GNSS service 总被引：3，自引：2，他引：1
The International GNSS Service (IGS) has been producing the total troposphere zenith path delay (ZPD) product that is based on combined ZPD contributions from several IGS Analysis Centers (AC) since GPS week 890 in 1997. A new approach to the production of the IGS ZPD has been proposed that replaces the direct combination of diverse ZPD products with point positioning estimates using the IGS Combined Final orbit and clock products. The new product was formally adopted in 2007 after several years of concurrent production with the legacy product. We describe here the advantages of the new approach for the IGS ZPD product, which enhance the value of the new ZPD product for climate studies. We also address the impact the IGS adoption in November 2006 of new GPS antenna phase center standards has had on the new ZPD product. Finally we describe plans to further enhance the ZPD products. 相似文献
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