Sea Surface Current Measurements Using Along-Track Interferometric SAR

摘要: Ocean currents affect the weather, climate and marine ecosystem. Observing ocean is important for understanding upper-ocean layer dynamics its interaction with other components of system. In-situ measurements are sparse their deployment maintenance costly. Satellite remote sensing large spatial coverage offers a good complement to in-situ observations. In this work we have studied spaceborne Along-Track Interferometric SAR (ATI-SAR) measuring sea surface currents. The measurement principle based on fact that phase difference between two acquisitions directly related radial (line-of-sight) velocity illuminated surface. Previous studies similar systems were carried out in areas well defined strong tidal ( 1 -3 m /s). demonstrate capability ATI-SAR, through several study cases, weak ( <0.5 This challenging satellite because it requires very accurate processing retrieval algorithms. addition, has been found wave motion contribution, systematically dominates measured ATI-SAR these current areas. Estimation motion  contribution relies high-resolution wind data. Thus, speed algorithm from needed support retrieval. We shown an appropriate applying necessary corrections agreement circulation models achieved (rmse = 0.1 m/s). These include calibration wind  compensation correct instrument geophysical systematic errors, respectively. Finally, novel method removing direction ambiguity, phase, presented. previous methods, ambiguity removal was external information, e.g. atmospheric model or visual observation shadows.