Ej. Christensen et al., OBSERVATIONS OF GEOGRAPHICALLY CORRELATED ORBIT ERRORS FOR TOPEX POSEIDON USING THE GLOBAL POSITIONING SYSTEM, Geophysical research letters, 21(19), 1994, pp. 2175-2178
We have compared Global Positioning System (GPS)-based dynamic and red
uced-dynamic TOPEX/Poseidon orbits over three 10-day repeat cycles of
the ground-track. The results suggest that the prelaunch joint gravity
model (JGM-1) introduces geographically correlated errors (GCEs) whic
h have a strong meridional dependence. The global distribution and mag
nitude of these GCEs are consistent with a prelaunch covariance analys
is, with estimated and predicted global rms error statistics of 2.3 an
d 2.4 cm rms, respectively. Repeating the analysis with the post-launc
h joint gravity model (JGM-2) suggests that a portion of the meridiona
l dependence observed in JGM-1 still remains, with a global rms error
of 1.2 cm.