基于高分五号DPC 氧气A 吸收波段的云顶压强反演

云顶压强可用于估计云高, 对气象观测和云特性研究等具有重要的作用。基于高分五号卫星搭载的多角度偏 振探测仪 (DPC) 在氧气 A 吸收带设置的 763 nm 和 765 nm 两个波段进行了云顶压强反演方法的研究。首先, 通过辐 射传输模拟和多项式拟合得到了大气压强的计算公式, 并对拟合公式进行了误差分析和校正。然后, 分析了气溶胶、 大气廓线等因素对云顶压强反演结果的影响, 并进一步利用晴空地表对反演方法进行了稳定性测试和原理性验证。 测试结果表明氧气 A 带方法稳定性较好, 可以适用于不同天气状况和观测角度; 验证结果表明 DPC 反演压强与 DEM 估算压强有很好的一致性, 地表压强的平均偏差约为 47.6 hPa。最后, 将 DPC 反演的云顶压强与 MODIS 云顶压强产 品 (MYD06) 进行了对比, 结果表明两颗卫星的云顶压强观测结果具有较好的空间一致性。

Retrieval of Cloud Top Pressure in Oxygen A-band Based on Data From DPC Onboard GF-5 Satellite

Cloud top pressure can be used to estimate cloud height, which is important for meteorological observation and cloud characteristics research. Based on 763 nm and 765 nm bands (in oxygen A-band) of the Directional Polarimetric Camera (DPC) onboard GF-5 satellite, a cloud top pressure retrieval method is studied. First, the calculation formula of atmospheric pressure is obtained by using radiative transfer simulation and polynomial fitting, and the fitting error of the formula is analyzed and corrected. Then, the influence of aerosol, atmosphere profile and other factors on the cloud top retrieval is analyzed, and the stability test and principle verification of the retrieval method are further carried out by using clear-sky surface. The stability test results show that the oxygen A-band retrieval method is stable and can be applied to different weather conditions and view angles, and the principle verification results show that the DPC retrieved pressure is in good correlation with the DEM estimated pressure, with the average deviation of surface pressure of 47.6 hPa. Finally, the retrieved DPC cloud top pressure is compared with the MODIS cloud top pressure product (MYD06), and it is shown that cloud top pressure observation results of the two satellites are in good agreement.