Radar Altimetry Radar altimeters can be used to calculate the sea surface height by measuring the travel time from the radar to the surface below. Past and operational altimeters include Geosat, TOPEX, Geosat-Follow On, ERS-1&2, and Jason-1. Check out the Links Page. ABYSS Altimetric Bathymetry from Surface Slopes ABYSS proposes a Delay-Doppler Altimeter on the International Space Station to measure the calculate the ocean bathymetry from measuring the ocean's surface slope. Water Inclination Topography and Technology Experiment WITTEX proposes a constellation of Delay-Doppler Altimeters to measure the Sea Surface Height of the oceans and provide two diemensional velocity fields. Delay Doppler Phase-Monopulse Altimeter (D2P) The aircraft mounted D2P radar was built under funding from NASA's Instrument Incuabator Program. It was built to measure the slope of continental ice sheets. Depth Sounder Algorithm Comparison The Depth Sounding algorithm is a new techniques for performing precise altimetry to obtain ice depth profiles. Geosat Synthetic Geoid The Geosat Synthetic Geoid created for the Gulf Stream area allows any altimeter flying in the Geosat Exact Repeat Mission's ground track to calculate the absolute Sea Surface Height. David.L.Porter@jhuapl.edu © The Johns Hopkins University Applied Physics Laboratory