Geolocation accuracy investigations with Sentinel-1

This contribution analyses the geolocation accuracy of Sentinel-1 in the IW mode. Considering the geolocation accuracy has been investigated in the frame of the corresponding commissioning phases for the S1A and S1B units, this contribution is focused on certain aspects not addressed before. On the first place, the 2D (range / azimuth) geolocation accuracy will be addressed by taking into account certain processing aspects that are currently not being corrected by the operational Sentinel-1 processor. On the second place, the geolocation accuracy is also evaluated in elevation by exploiting a stack of images and the corresponding spread of the perpendicular baselines in order to perform imaging in the direction perpendicular to the line of sight, i.e., tomographic imaging. The following two paragraphs are dedicated to describe both investigations. In order to perform the analysis, an ascending stack of Sentienl-1A images acquired over DLR s calibration test site close to Munich has been used, which is composed of 18 images acquired between November 25, 2015 and July 22, 2016.