基于CALIOP数据的海雾检测方法研究

A Method for Sea Fog Detection Using CALIOP Data

提出了一种基于星载激光雷达CALIOP数据检测海雾的方法。通过对比分析不同条件下低云和低空气溶胶的衰减后向散射特性,以及研究CALIOP海表误判区的衰减后向散射特性,发现了海表误判区其实是一种与海表相接的云,即海雾。继而,通过反演海表误判区的消光系数和能见度,发现98%以上海表误判区的消光系数低于1km,对该方法进行了检验验证。本文所提出的海雾检测方法丰富了海雾案例选取途径,拓展了海雾样本点来源,对研究海雾特性具有积极意义。

A method for sea fog detection using the measurement data acquired by the Cloud-Aerosol Lidar with Orthogonal Polarization（CALIOP）aboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation（CALIPSO）satellite is proposed in this paper.The characteristics of the backscattersoflow clouds and low aerosols under two different conditions were analyzed.The statistics of 3 bins below cloud top expresse the real characteristics of backscatters preferably.However,there is no difference for aerosol under the two conditions.Then the characteristic of backscatter for misjudgedsea surface is analyzed and compared with cloud and aerosol.It makes out that the misjudged sea surface is a kind of cloud whose base is attached with sea surface.Summarily the misjudged sea surface is sea fog.In order to verify this conclusion,extinction coefficient and visibility of sea surface which is misjudged were retrieved.It turned out that only 1.95 percent of visibility is greater than 1 kilometer and most of visibility is less than0.3 kilometer.So it reachesa conclusion that the misjudged sea surface is sea fog.The method of sea fog detection proposed in this paper has enriched the way to detect sea fog and made a difference on researching characteristics of sea fog.