Satellite Altimetry for Hydrology - A review

摘要: Water is a critical natural resource upon which all social and economic activities ecosystem functions depend. However, regular gauging networks fail to provide the information needed for spatial coverage timely delivery. Although space missions discussed here were not primarily dedicated hydrology, 20 years of satellite altimetry have furnished complementary data that can be used create hydrological products river basin, such as time series stages spread throughout basins, estimated discharges rivers, derive longitudinal altitude profiles bed, lowest highest stages, or leveling in situ stations. Raw still suffer uncertainties several decimeters. These require specific reprocessing waveform retracking geophysical correction editing; much work remains done. Inundated surfaces, variations their extent, are currently almost routinely computed using imagery. Today, techniques evolving rapidly. One direction change radar band, from Ku Ka. Other replacement today LR Mode SAR Interferometry modes. Both evolutions tend diminish dramatically ground footprint, reducing contamination echo by environment water body, improving vertical accuracy. Last, 2015, research class will replaced operational ones, making long living sampling locations more certain. All aforementioned technical grouped SWOT mission, Ka band interferometric swath altimeter, first mission actually full continental waters, launched early 2020's. Besides its intrinsic improvement high resolution height, slope width reaches, an invaluable tool put altogether inter-calibrated dataset nadir missions' part constellation.