To obtain high accuracy polarization observation information is highly expecting in aerosol parameter retrieval and atmosphere environment research. In this paper, we described a space-borne multispectral polarized scanning atmospheric corrector (PSAC), which can provide extremely high polarimetric accuracy. And we use wavelet-based denoising method to improve the stability of PSAC measurement results by reducing internal noise. The result shows that the STD of DOLP difference between PSAC measurement value and theoretical value is significantly reduced, reached 5%~10% in the requirement DOLP difference accuracy 0.5%, the proposed threshold function can increase the evaluation accuracy stability of instrument polarization and reduce the uncertainty, also, the measurement results of PSAC inflight improved as well.
In order to meet the application requirements of a space borne polarizing radiometer infrared band, a high-precision on-orbit temperature control scheme for the infrared detector combining active temperature control and passive temperature control is proposed. The infrared detector is installed on the heat sink copper block, and the temperature of heat sink copper block is controlled at -20°C~-30°C through the method of auxiliary cold plate + heat pipe thermal conduction. Combined with the infrared detector built-in three-level thermoelectric cooler, the photosensitive surface temperature of the infrared detector is cooled to below -60°C by a method of constant current driving. In order to ensure the measurement accuracy of infrared radiation polarization, the short-term temperature fluctuation of the photosensitive surface of the infrared detector is required to be less than 0.03°C/s. This article has designed the infrared detector temperature control scheme verification test, and actually measured the stability of infrared detector temperature and dark current. The results of the simulation and tests show that the range of infrared detector heat sink temperature is - 25±5°C, the range of infrared detector photosensitive surface temperature is -65°C ～ -75°C,the rate of short-term temperature change of the infrared detector photo-sensitive surface is better than 0.01°C/s, and the dark current fluctuation is less than 1.3pA. Satisfying the on-orbit high-precision polarization measurement requirements.