Validation of JASON-3 Altimeter Using Tide Gauges Around North America

摘要

We present the validation results of Jason-3 altimeter using 38 tide gauges around North America. The EGM2008 and FES2004 are used to achieve the geoid and tide differences between the tide gauges and altimeter footprints. The GPS reference stations not far from the tide gauge are processed to detect the effect of land movements. The results show that the land movements do not make significant affects to the validation, the drift of altimeter is +6.9 mm/cycle in 0~7 cycles, which may be caused by the instability of the instruments during the first 8 cycles. And then it shows a good performance during 8~32 cycles, with a tendency drift of -1.1mm/cycle. The wet zenith delay derived from the advanced microwave radiometer is also validated by the ECMWF model. The total difference is at the 20 mm level. The comparison result has a standard bias of 1.0~7.3 mm when the footprint is 50 away from land, which represents a good performance. When the distance is 20~25 km from land, the standard bias is about 1.8 cm. While for the distance of less than 15 km from the coast, the difference between the MWR and ECMWF is 2.1~14 mm.