Abstract:Accurate measurement of the radiative properties of clouds and aerosols is of great significance to global climate change and numerical weather prediction. The polarization payload mounted on the Fengyun-3 precipitation satellite is the first domestic multiangle polarization imager (PMAI) with short-wave infrared channels. It is planned to be launched at the beginning of 2023, providing important support for the aerosol-cloud-precipitation observation chain. The instrument operates in a non-sun-synchronized inclined orbit and provides images with a spatial resolution of 3 km (sub-satellite) and a width of 700 km. The observation channels of PMAI include 1030 nm, 1370 nm, and 1640 nm polarization channels and corresponding non-polarization channels, which can provide observation information from 14 angles. PMAI will utilize onorbit vicarious calibration of natural targets and cross-calibration of instruments on the same platform to achieve 5% radiometric accuracy. PMAI has the unique advantage of characterizing clouds and aerosols. The multi-angle polarization measurement of the new short-wave infrared channel can optimize cloud phase state identification and cloud micro-physical parameter inversion, as well as ground-air decoupling of aerosols, and at the same time, characterize surface directional reflection characteristics. The unique observation geometry of non-sun-synchronous orbits can make full use of the distribution characteristics of earth-atmosphere radiation with scattering angles for parameter inversion. In addition, PMAI can optimize cloud and aerosol retrieval in conjunction with the observational information of the visible, near-infrared and thermal infrared channels of the mid-resolution spectral imager on the same platform.