Rain Impact on Sensitivity of Ka-band Scan-on-Receive Synthetic Aperture Radars

This paper analytically analyses the radiometric performance of a spaceborne Ka-band SAR based on scan-on-receive Rx antenna beam. The analysis outlines the major limiting factors for the design of this instrument. The instrument radiometric sensitivity is evaluated considering a figure of merit that includes the signal-to-noise ratio and the signal-to-rain clutter ratio as well as. In the simulations, different rainfall rates are considered, and the instrument availability for given performance is evaluated. Potential instrument configurations and geometric options are traded-off in order to find the optimal configuration. The analyses show the scan-on-receive technique as a potential solution leading to spaceborne Ka-band synthetic aperture radars with sufficient availability.