高分五号卫星同时搭载了温室气体探测仪(GMI)和大气多角度偏振探测仪,两者在云检测方面各有优势,但是均存在局限。提出了一种基于两者数据的协同云筛选新算法以提高温室气体反演中的云筛选效率。利用该算法检测了全球16 d在轨实测数据中的77581个GMI观测点,筛选出晴空观测点9508个,占比为12.26%。利用融合后的中分辨率成像光谱仪云掩模和卷云反射率数据集,验证了该算法进行云检测的正确率,得到陆地上和海洋上的云检测正确率分别为92.93%和81.91%。

The GaoFen-5 satellite is equipped with a greenhouse gas monitoring instrument (GMI) and a directional polarization camera. Both devices have their own advantages as well as limitations in cloud detection. This study proposes a novel collaborative cloud screening algorithm that uses data from both devices to improve the efficiency of cloud screening for greenhouse gas retrieval. This algorithm is tested with 77581 GMI observation points from the global 16-day on-track measured data, and 9508 clear-sky observation points, i.e. 12.26% points are screened. With the fused moderate resolution imaging spectro-radiometer cloud mask and cirrus reflectance dataset, the validity of cloud detection by the proposed algorithm is confirmed. The accurate rates of cloud detection of 92.93% and 81.91% over land and oceans are obtained, respectively.