Sub-Centimeter Precision Orbit Determination with GPS for Ocean Altimetry

Edited: 2011-02-18
TitleSub-Centimeter Precision Orbit Determination with GPS for Ocean Altimetry
Publication TypeJournal Article
Year of Publication2010
AuthorsBertiger, W., S. Desai, A. Dorsey, B. J. Haines, N. Harvey, D. Kuang, A. Sibthorpe, and J. Weiss
JournalMarine Geodesy
Issue1 supp 1
Keywordsjason, sea_level
AbstractWe assess the accuracy of JPL's estimated OSTM/Jason-2 Global Positioning System (GPS)-determined orbits based on residuals to independent satellite laser ranging (SLR) data, compared with orbits produced by different software from different data (SLR/DORIS), Geophysical Data Record version C (GDR-C) orbits, and altimeter crossover tests. All of these tests are consistent with sub-cm radial accuracy: high elevation SLR residual standard deviation lies at 6.8 mm, RMS differences from GDR-C in the radial component typically fall below a cm, and altimeter crossovers from JPL orbits have a variance 89 mm^2 smaller than altimeter crossovers from GDR-C orbits. Although RMS differences between radial components of different orbit solutions typically lie below a cm, we observe systematic dependences on both time and geography. The improved precision and accuracy of JPL's OSTM/Jason-2 orbit solutions rely on a new algorithm for applying constraints to integer carrier phase ambiguities. This algorithm is sufficiently robust to improve solutions despite half-cycle carrier phase identification issues in OSTM/Jason-2's BlackJack receiver. Although Jason-1 receiver performance differs, our algorithm should extend to Jason-1 processing (during the time span of nominal GPS receiver operations).