標題: Modeling Orbit Dynamics of FORMOSAT-3/COSMIC Satellites for Recovery of Temporal Gravity Variations
作者: Hwang, Cheinway
Lin, Ting-Jung
Tseng, Tzu-Pang
Chao, Benjamin Fong
土木工程學系
Department of Civil Engineering
關鍵字: FORMOSAT-3/COSMIC (COSMIC);GPS;GRACE;kinematic orbit;temporal gravity
公開日期: 1-Nov-2008
摘要: The precise GPS high-low tracking data from the joint Taiwan-USA mission FORMOSAT-3/COSMIC (COSMIC) can be used for gravity recovery. The current orbital accuracy of COSMIC kinematic orbit is 2 cm and is better than 1 cm for 60-s normal points. We model the perturbing forces acting on the COSMIC spacecraft based on standard models of orbit dynamics. The major tool for the numerical work of force modeling is NASA Goddard's GEODYN II software. Considering that COSMIC spacecrafts are not equipped with accelerometers, the accelerations due to atmospheric drag, solar radiation pressure, and other minor surface forces are modeled by estimating relevant parameters over one orbital period from COSMIC's kinematic and reduced dynamic orbits. We carry out experimental solutions of time-varying geopotential coefficients using one month of COSMIC kinematic orbits (August 2006). With the nongravity origin forces properly modeled by GEODYN II, residual orbital perturbations (difference between kinematic and reference orbits) are assumed to be linear functions of time-varying geopotential coefficients and are used as observations to estimate the latter. Both COSMIC and combined COSMIC and GRACE gravity solutions are computed. The COSMIC solution shows some well-known temporal gravity signatures but contains artifacts. The combined COSMIC and GRACE solution enhances some local temporal gravity signatures in the GRACE solution.
URI: http://dx.doi.org/10.1109/TGRS.2008.2004789
http://hdl.handle.net/11536/8181
ISSN: 0196-2892
DOI: 10.1109/TGRS.2008.2004789
期刊: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
Volume: 46
Issue: 11
起始頁: 3412
結束頁: 3423
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