Radiometric Calibration of the Three-Channel Imaging Polarimeter

Radiometric calibration is of critical importance for information quantification of imaging polarimeters. In this paper, an integral sphere which had been traced to cryogenic radiometer was used as transfer standard in our calibration facility. The linearity, uniformity, stability of our imaging polarimeter were calibrated. The combined uncertainty in the responsivity of an imaging polarimeter was about 7.5%. At last, technical proposals of reducing uncertainty budget were briefly discussed.