Automated Technique for Locating the Gulf Stream in Altimeter Profiles

摘要

Several satellite-borne radar altimeters have been in space, beginning withSkylab in 1973, followed by GEOS-3 in 1975, and SEASAT in 1978. In 1985 the U.S. Navy launched the GEOSAT altimeter. The purpose of GEOSAT was to measure the oceanic geoid. The GEOSAT primary mission began with its launch on March 12, 1985, into an 800-kilometer-altitude, 108-degree-inclination orbit that generated a ground track grid with 4 kilometer spacing. Sea level observations over this grid continued for 18 months. On October 1, 1986 the satellite was maneuvered into a 17-day exact repeat orbit optimized for collecting oceanographic data. During this exact repeat mission (ERM) the GEOSAT space orbit specifications in order to allow unclassified distributions of the data to users. The ERM terminated on January 5, 1990 due to instrument failure. This reprint presents a new approach to determining the location of the Gulf Stream in altimeter profiles. The new technique avoids the problem of oceanographic contamination of the geoid by using a polynomial as a equipotential reference surface. Automation of the Gulf Stream location problem is also accomplished by using the linear Hough transform as a detection and location paradigm. (kr)