Absolute Calibration of Satellite Altimetry using Tide Gauges: Case Study of the Persian Gulf

This paper describes the use of Iranian tide gauges to instantaneously measure sea level in same geocentric reference frame as altimetry data for TOPEX/Poseidon (T/P), Jason-1 and Jason-2 to provide ongoing absolute calibration of altimeter bias near the Persian Gulf in Iran. The method makes use of Iranian tide gauges that use GPS receivers to measure sea surface heights synchronously and in the same geocentric reference frames as the altimetry heights recorded. Three Iranian tide gauges at Bushehr, Bandar Abbas and Chahbahar ports and Geophysical Data Records (GDR) for TOPEX/Poseidon (T/P), Jason-1and Jason-2 were used to estimate a bias for each altimeter. Biases obtained for TOPEX/Poseidon (T/P) were -6 mm and for Jason-1 were 121 mm and for Jason 2 is 198 mm in Bushehr. Datum connections between the tide gauge and altimetric sea surface heights were calculated by means, geoid differences using the Earth Gravitational Model 1996 (EGM96).