Sentinel-1 A and B are twin spaceborne C-band synthetic aperture radar (SAR) sensors developed and operated
by the European Space Agency under the Copernicus Earth Observation programme. An accurate geometric calibration has been performed since the Commissioning Phases on operationally generated Level-1 SAR products.
In this paper we address the new improvements to the geometric calibration of Sentinel-1A and -1B products, describing corrections applied to the data to remove artefacts such as swath-dependent biases that had previously
been observed in corner reflector measurements.