A correlated noise calibration source for the internal calibration of a fully polarimetric radiometer

A novel microwave calibration source for a fully polarimetric radiometer (FPoR) is proposed for internal calibration by the electrical operation instead of a mechanical structure at S-band. The proposed correlated noise calibration source (CNCS) using microwave components can generate vertical and horizontal polarized signals; additionally, linearly and circularly polarized signals (third and fourth Stokes parameters) are also estimated by injecting correlated noise. In contrast to existing mechanical calibration sources, this calibration source can be designed by miniaturization. Based on measured quantities under realistic conditions, the uncertainty was evaluated according to the states of the SPDT switches and phase shifters of the CNCS.