Calibration Concepts for Future Low Frequency SAR Systems

Abstract:
SAR technology is widely used in frequency at L-, S-, C-, and X-band. Upcoming spaceborne SAR missions will use even longer wavelength, like Biomass at P-band. The required large antenna aperture size for good performance is realized by a large offset reflector antenna. Also Tandem-L, a propose mission of Japanese JAXA and German DLR, uses a reflector antenna for a high performance SAR sensor at L-band. This reflector antenna technology together with comparatively long wavelength and hence large structures leads to new challenges in the calibration of these future spaceborne SAR missions. Furthermore, additional perturbations caused by the ionosphere have to be considered in modelling the propagation path between SAR sensor and calibration target.