Characteristics of Surface NRCS and the Effect on theSpaceborne Precipitation Radar System Design

The analysis on the statistical characteristics of the surface Normalized Radar Cross Section (NRCS) is the foundation of the Spaceborne Precipitation Radar (SPR) system design, but it is very difficult and costly to measure the global NRCS in long time and the study results about the Ku band global NRCS at small incidence angles are very few in China. In this paper, statistical analysis on the surface NRCS measured is performed by the Tropical Rainfall Measurement Mission (TRMM) satellite in 2011. The results manifest the relations between the statistical characteristics of the surface NRCS (such as mean and standard deviation) and incidence angles. The influence of NRCS statistical characteristics on the SPR system design is analyzed in the parts of system dynamic range, range side-lobes, antenna side-lobes and radar calibration. These analysis results are the foundations of the radar system requirement analysis and radar calibration method selection.