Platform Scattering Analysis of the Copernicus Imaging Microwave Radiometer

The Copernicus Microwave Imaging Radiometer (CIMR) employs a 7.1 m conical scanning mesh reflector antenna rotating at 7.8 rpm that operates from L to Ka band. Demanding radiometric accuracies and sensitivities at few tenths of a Kelvin at high spatial resolution are targeted for the instrument. These require a high accuracy in the characterisation and modelling of the antenna pattern over 4π, considering any nearby scattering structure and/or any potential multipath due to the antenna installation over the S/C. Moreover, the quantification of the fractional power hitting each scatterer entering by reciprocity into the feeds is also of primary importance, since it can bias the antenna temperature. A platform scattering analysis of the reflector antenna on the CIMR satellite was thus undertaken for a subset of feeds at L, C, X, K, and Ka bands. In this paper we describe the analyses done and summarise the effect of these scatters over the antenna RF performances.