The aim of the paper is to describe a ground-based microwave scatterometer demonstrator dedicated for the functional verification of MICAP (Microwave Imager Combined Active and Passive). MICAP has been selected to be one of the main payloads for future Chinese ocean salinity mission. The MICAP scatterometer is for estimating ocean surface roughness which measurement will enable the removal of the wind effect from the ocean surface brightness temperature measurement being used to retrieval ocean salinity. The primary technical challenge is its end to end system stability, on the order of 0.1dB. A demonstrator was developed to verify functionality and provide support to trouble shooting in the following project phases. The demonstrator's development and integration, as well as the stability calibration are discussed in the paper.
