Littoral antenna deconvolution for a microwave radiometer

The standard on orbit data processing used by all current and upcoming satellite altimetry missions (TOPEX/Poseidon, GEOSAT Follow On, and Jason-1) results in a radar altimeter footprint which is generally much smaller than the footprint of the microwave radiometer that is used to correct for path delay of the radar signal by tropospheric water vapor and clouds. As a result, the quality of ocean topology retrievals can be compromised in coastal environments even when the altimeter itself is still operating nominally. For example, the diameter of the TOPEX altimeter footprint is 3-5 km at typical wind speeds, but the radiometer has a 35 km footprint at 21 GHz. Because of this size disparity, wet path delay corrections are generally not considered reliable within approximately 50 km of a major coastline. We present here an antenna deconvolution procedure which is specifically intended to improve near-coastal retrieval of the wet tropospheric path delay correction by satellite altimeters. The procedure has immediate applications with archived and current TOPEX/Poseidon data, and will be applicable to the upcoming GFO and Jason-1 missions, for the imaging of ocean currents and tides in the littoral zone