基于对运动做出贡献的像元指定卫星风高度的算法研究

The proposed project is a part of the research work underwent in the National Satellite Meteorological Center (NSMC) aimed at improving quality of the Atmospheric Motion Vectors (AMVs) by revising height assignment algorithm for thin cirrus clouds as tracer. Both the practical and the theoretical aspects will be referred. In the previous wind derivation algorithm, tracers are treated as an entire body. Since the moving pixels in the tracer are not well identified, the wind speed in magnitude and the wind location in height are not accurately evaluated. The proposed research project will be realized in the following aspects: ① to search practical ways to find the moving pixels, ② to examine appearance, recognition and classification of the moving pixels, ③ to find proper ways to use parameters from the moving pixels at the wind deviation and the height assignment, ④ to understand mechanism on the algorithm improvements verified in practice through further investigation with radiation transfer model, ⑤ to evaluate contribution of radiation from the underlying environment below thin cirrus to the satellite observation. The proposed research project will make contribution to the quality improvements of AMVs from FY2 satellites and to the quantitative application of FY2 AMVs in the NWP model.

本课题申请是国家卫星气象中心多年来为改善卫星风质量所进行研究工作的一部分，试图探索改善薄卷云风高度指定的基础理论问题和算法。先前的卫星风算法，把示踪图像块作为整体进行处理，不仅风速估计偏低，而且难以精细地考察对运动做出最大贡献的云在高度指定中所起的作用。本研究课题在示踪图像块中选择对运动做出最大贡献的像元，用这些像元的参数及其订正值做卫星风的高度指定，分析资料的表现，解释其中的机理，选择典型案例进行辐射传输模拟。通过研究对运动做出最大贡献图像像元的识別和分类、来自云下背景辐射强度信息的提取、典型案例的辐射传输模拟，改善薄卷云高度指定的精度，为我国静止气象卫星的风产品进入数值预报模式做贡献。