关键词: 高光谱观测卫星, 细颗粒物探测, 偏振交火, 交叉定标

Abstract: Hyperspectral observation satellite, launched on September 7, 2021, is an operational satellite planned in the "National Medium-and Long-Term Development Plan for Civil Space Infrastructure (2015-2025)", and is an important symbol of China's hyperspectral remote sensing capability. The satellite operates in a sun-synchronous orbit with an altitude of 705 km and a local time of dscending node of 10:30 AM. For the detection of fine particulate matters, the satellite is equipped with a dual-polarization crossfire payload suite composed of a high-precision particulate obersving scanning polarimeter (POSP) and an atmospheric multi-angle aerosol directional polarization camera (DPC), so aerosol information such as AOD and PM2.5 can be obtained through the joint detection of dual-polarization payloads. This paper mainly introduces the overall technical scheme of the hyperspectral satellite and the dual polarization payloads, and elaborates on the key design points of polarization crossfire mechnism, including the engineering design of timing, spectral channel selection, spectral channel matching and field of view matching. At the same time, the on-orbit performance of the polarization crossfire detection mode is evaluated. The results show that the time synchronization accuracy of the dual-polarization payload is better than 0.4 ms, and the field of view matching accuracy is better than 0.066 pixel of POSP, meeting the requirement of aerosol inversion. Finally, the in-orbit measurement performance of dual-polarization payloads is cross-verified. It is shown that the fitting determination coefficient of radiation measurement and reference value is higher than 0.96, and the average absolute difference of linear polarization is better than 0.0088, which meets the design requirements of in-orbit detection accuracy.

Key words: hyperspectral observation satellite, fine particulate matters detection, polarization crossfire; cross calibration