Continuous monitoring of the Jason-1 and TOPEX/Poseidon ocean altimetry missions from dedicated calibration sites

We present calibration results from Jason-1 and TOPEX/Poseidon overflights of the three dedicated verification sites: (1) a California offshore oil platform (Harvest); (2) the Mediterranean island of Corsica (Cape Senetosa), and (3) the Bass Strait off the coast of Tasmania. The high-accuracy of the Jason-1 measurement system is evident in the results from the dedicated calibration experiments. These experiments do indicate, however, that the Jason-1 sea-surface-height (SSH) measurements are biased high by approximately 12-15 cm. We discuss the implications of geographically correlated errors on the determination of the SSH bias.