Antenna temperature calibration algorithm and design of the calibration experiment for spaceborne microwave radiometers

Calibration of microwave radiometer is the procedure and processing to setup a quantitive relationship between the output of the instrument, which usually is the digital sampling of the receiver output voltage, and microwave emission incident on the receiving antenna. Design of the calibration subsystem of a spaceborne microwave radiometer with fixed pointing antennas is described in this paper. The calibration equation is derived based on this design, by modeling the radiative transfer of microwave emissions, from input of the receiving antennas to the output of the calibration switches inside the receivers. Then a calibration experiment is designed to test the calibration model and acquire the calibration coefficients.