Quasi geostationary, comsat-compatible SAR: Solutions for payload design

The paper proposes two different architectural solutions for a quasi-geostationary monostatic SAR, hosted on-board of a COMSAT satellite, aiming at monitoring water-vapor, for Numerical Weather Forecast on a sub-continental scale, and hazards like hydrogeological landslides and deformations on a local scale. The two architectures address a system that combines an L-band, wide coverage beam, for coarse resolution imaging, and an X-band, spot beam, for fine resolution imaging. The challenge is to allow the X-band spot to be positioned everywhere within the L-band coverage, that should be hold fixed, but exploiting the same wide reflector.