Correcting for Cryoprecipitation in the Calibration of IR Channels of the MSU-MR Radiometer

Abstract

The presence of cryoprecipitation, which forms a thin film on the input windows of infrared (IR) detectors and distorts the signal, is a major issue in calibration of IR channels of the multispectral scanning imager–radiometer (MSU-MR) aboard Meteor-M No. 2. A model of signal attenuation in transmission through such films and a method for calculating this attenuation were developed. Correction functions for the detected signal were obtained. The developed algorithms were used for cross-calibration between the MSU-MR IR channels and the corresponding channels of the advanced very-high-resolution radiometer of MetOp satellites. An algorithm for calculating the sea surface temperature (SST) based on the non-linear SST technology (split-window technology) was developed and verified by comparison with in situ data. The SST calculation error was less than 0.8°C for the entire sample, which satisfies world quality standards. The stability of calibration parameters within an interval of two years was demonstrated.