LONG-BASELINE KINEMATIC GPS DATA ANALYSIS FOR ENVISAT RADAR ALTIMETER CALIBRATION

摘要

Satellite-based radar altimeters like the one on board of ENVISAT exhibit a bias which needs to be determined by an elaborate field campaign. GPS-equipped buoys are a suitable means for this purpose since it is possible to determine the sea-surface height at the time of cross-over with sufficient accuracy. However, high-precision kinematic GPS positioning usually requires one to establish at least one reference station in the vicinity of the buoys which is an additional investment of money and manpower. This paper focuses on the utilization of existing stations of the IGS and EUREF networks which are far away from the roving receivers. It is demonstrated that kinematic GPS processing via such long baselines for purposes of radar altimeter bias recovery is feasible, although successful integer ambiguity fixing may not always be possible.