How Does Multiple Scattering Affect the Spaceborne W-Band Radar Measurements at Ranges Close to and Crossing the Sea-Surface Range?

摘要

A radar simulator capable of treating multiple scattering effects has been upgraded to include the interaction with a Kirchoff surface, which realistically reproduces the effect of water surfaces. Multiple-scattering effects explain in a straightforward way some peculiar features of the first images delivered by the 94-GHz cloud-profiling radar onboard the CloudSat, overpassing precipitating systems. The reflectivity profiles without the usual peaks at surface range are found to be distinctive signatures of strong multiple scattering. Moreover, multiple scattering is responsible for producing long signal tails at apparent ranges far below the surface with a strong sensitivity on the microphysical assumptions of the icy segment of the cloud. The estimates of multiple-scattering enhancement at surface and close to the surface range and the saturation levels for simplified precipitating profiles for both CloudSat and EarthCARE configurations are provided.