基于双频星载降水雷达的全球三维降水反演研究

Precipitation is a meteorological element as well as hydrological element, which is an important factor in global energy and water circulation. Spaceborne precipitation radar is a valid instrument to detect precipitation's three dimensional distribution in global scale. Radar can penetrate cloud, rain and atmosphere, and measure precipitation's vertical structure directly with high range resolution. This project plans to simulate dual-frequency precipitation data based on single-frequency spaceborne precipitation radar observation data, and validate the simulation method using data obtained in China's first field campaign of dual-frequency precipitation radar. Dual-frequency retrieval algorithm will be developed, which estimates drop size distribution in the radar's 3D observation cell and provides global precipitation's 3D structure. Synthetical evaluation principle based on different retrieval algorithms will be established to fulfill a new synthetical application system, which is believed to improve the retrieval accuracy ultimately. Retrieval algorithm's performance will be evaluated using matched observation data, from space as well as ground, and error analysis will be carried out. This project will develop dual-frequency data processing model of spaceborne precipitaion radar, and retrieve global precipitation's 3D structure, providing critical information for global atmospheric circulation modeling, water cycle modeling and climate research.

降水是一种气象要素，也是一种水文要素，是全球能量和水循环中的重要因子。星载降水雷达是探测全球降水三维分布的有效手段，雷达能够穿透云雨大气，以较高的距离分辨率直接测量降水的垂直结构。本项目拟使用单频星载降水雷达实测数据模拟双频降水数据，并利用我国首次双频降水雷达机载校飞试验实测降水数据验证模拟方法的有效性；在此基础上，开发双频反演算法，估计雷达三维分辨单元的滴谱分布模型参数，准确反演全球降水三维结构；建立综合评估方法，实现基于多种算法的综合应用系统，提高降水反演精度；对星、地降水观测资料进行时空匹配处理，评估反演算法性能，并完成不确定性与误差分析。本项目拟最终建立双频降水雷达数据处理模型，反演全球降水三维结构，为全球大气循环建模、水循环建模和气候研究提供关键的研究数据。

降水是一种气象要素，也是一种水文要素，是全球能量和水循环中的重要因子。星载降水雷达是探测全球降水三维分布的有效手段，雷达能够穿透云雨大气，以较高的距离分辨率直接测量降水的垂直结构。本项目探索了使用单频星载降水雷达实测数据模拟双频降水数据的方法，并利用我国首次双频降水雷达机载校飞试验实测降水数据，验证了模拟方法的有效性。在此基础上，实现了双频反演算法，可以反演得到降水的三维结构；并通过对算法的优缺点分析及不确定因素的分析，提出基于不同反演算法的优化流程；对星、地降水观测资料进行时空匹配处理，开展了定性比较与点对点定量比较，建立了高效的星地资料对比方法。本项目为我国风云三号即将搭载的降水测量雷达数据处理进行了先期探索，建立的双频降水雷达数据处理模型可应用于星载双频降水测量雷达的数据处理，为全球大气循环建模、水循环建模和气候研究提供关键的研究数据。