Experimental and Correction Methods for Responsivity Temperature Dependence in the SWIR Bands of a Spaceborne Scanning Polarimeter  
[PERSON]  
1,2, [PERSON]  
limit the on-orbit absolute radiometric accuracy. Therefore, Responsivity Temperature Dependence Correction (RTDC) must be performed; otherwise, the retrieval results obtained for the atmospheric parameters are directly affected [9; 10]. For some remote sensors working in harsh environments, responsivity temperature characteristic measurement and RTDC are important steps in the calibration process. Researchers have performed extensive research on this topic. [PERSON] et al. [11] focused on the problem wherein Moderate Resolution Imaging Spectroradiometer (MODIS) detectors may change with the temperature of the Focal Plane Assembly (FPA) affected by MODIS and the environment without precise temperature control of FPA. An instrument-level thermal vacuum experiment was conducted before the launch of the MODIS by simulating three different ambient temperatures and using an integrating sphere light source to obtain the RTDC coefficients of the solar reflection channels, and correction was applied to the onboard data pre-processing. [PERSON] et al. [12] performed similar work to obtain the RTDC coefficient of the Sea-viewing Wide Field-of-View Sensor (SeaWiFS) before launch, and the NASA Ocean Biology Processing Group (OBPG) calibration and validation team computed a revised set of RTDC for SeaWiFS with on-orbit periodic lunar calibration data and removed the significant periodic departures in the Near Infrared (NIR) bands (765 nm and 865 nm) from the mission-long trends [13]. As a preferred verification benchmark for atmospheric aerosol satellite remote sensing, the Aerosol Robotic Network (AERONET) suffers from similar problems wherein the responsivity of the 1020 nm channel in its core instrument CE-318 needs to be corrected for the temperature effect of its detector and the filter [14; 15]. Research has shown that the temperature drift of the operating environment may result in an Atmospheric Optical Depth (AOD) inversion error up to 0.02 [16]. To obtain the RTDC coefficient for each CE-318, [PERSON] [12; 17] measured this coefficient based on a temperature chamber in the laboratory, [PERSON] et al. [14] and [PERSON] et al. [15] compared the synchronous observation results of various instruments and reference instruments in the field, and [PERSON] et al. [18] acquired a coefficient with the improved Langley method. To determine the RTDC of the Directional Polarimetric Camera (DPC), [PERSON] et al. [19] constructed the relationship between the radiation response and the detector assembly temperature based on a thermal control design and a thermal vacuum experiment; the responsivity temperature dependence coefficient was obtained after dark signal correction and frame transfer correction. In the above research, a common strategy used to study the RTDC of remote sensors is instrument-level experiments. This method can obtain relatively accurate and reliable coefficients that benefit from the integrity of the experimental instrument. However, a challenging problem that arises in this method is high experimental costs and rigorous experimental conditions. We therefore analyzed a detector-level experiment and investigated whether its experimental results are substitutable for this type of detector. In this study, we first established an RTDC model of the PSAC. Then, the model coefficients over a large temperature range were obtained through instrument-level experiments in a thermal vacuum condition and ambient laboratory temperature. Moreover, based on targeted control of the identified experimental interference factors, the model coefficients were also determined through detector-level experiments at an ambient laboratory temperature. Finally, the models obtained from two types of tests and the corresponding temperature drift correction results were compared to verify the validity and substitutability of the detector-level experiment.