Abstract
A low-cost computer procedure to determine the orbit of an artificial satellite by
using short arc
data from an onboard GPS receiver is proposed. Pseudoranges are used as measurements to
estimate the orbit via recursive least squares method. The algorithm applies orthogonal Givens
rotations for solving recursive and sequential orbit determination problems. To assess the
procedure, it was applied to the TOPEX/POSEIDON satellite for data batches of one orbital
period (approximately two hours), and force modelling, due to the full JGM-2 gravity field model,
was considered. When compared with the reference Precision Orbit Ephemeris (POE) of
JPL/NASA, the results have indicated that precision better than 9 m is easily obtained,
even when
short batches of data are used.