Variation of Great Lakes water levels derived from Geosat altimetry

摘要: A technique for using satellite radar altimetry data to estimate the temporal variation of water level in moderate large lakes and enclosed seas is described. Great Lakes from first 2 years U.S. Navy's Geosat Exact Repeat Mission (November 1986 November 1988), which there an improved orbit, are used demonstrate technique. The results compared lake collected by Section, National Ocean Service, Oceanic Atmospheric Administration, found reproduce variations five major with root-mean-square error (rms) ranging 9.4 13.8 cm a combined average 11.1 cm. also analyzed Lake St. Clair, representing moderate-sized lake, resulting rms 17.0 During this study period, varied typical annual cycle about 0.2 m (0.5 Ontario) superimposed on general decline approximately 0.5 m. altimeter reproduced reasonably well all lakes, but was obscured some due systematic errors data. Current future missions will have markedly accuracy permit many (25 km diameter) or larger be routinely monitored.