Measurement of River Surface Currents using SAR Techniques

Abstract

The measurement of river currents can essentially contribute to determine river run-offs, whose knowledge is of great importance, e.g. in climate research. Remote sensing would be a convenient way to regularly monitor river currents on a large scale. The paper presents results from an airborne flight campaign in which SAR techniques were used to map and estimate river surface currents. As the radar backscatter of rivers is usually very low due to the lack of a rough surface, the test sites must be chosen carefully. From a radar point of view the surface patterns behave like moving objects. These cause several effects in SAR images such as azimuth displacements that complicate measurements. It is shown that by taking them into account the estimation of river currents with SAR techniques is possible.