一种提高TRMM测雨雷达反演准确性的方法(英文)

Method for Improving Retrieval Accuracy of TRMM Precipitation Radar

热带降雨测量卫星所携带的测雨雷达是世界上第一颗星载测雨雷达,对其反演算法展开研究在算法开发及数据应用等方面具有重要意义。本文在介绍NASA与JAXA反演雷达反射率因子的标准算法的基础上,对反射率因子反演算法进行了改进。改进算法根据星载测雨雷达每个观测单元上的降雨率计算出等效雨滴直径,对不服从瑞利散射的观测单元的反射率因子值进行修订,然后再执行衰减订正。本文采用了更合理的5km×5km×1.5km三维网格,将处理结果与地基雷达数据进行了点对点的定性与定量比较。结果表明,改进算法以较小的计算量增加为代价,获得了反演精度的提高。

The Precipitation Radar （PR） onboard Tropical Rainfall Measuring Mission （TRMM） is the first rain radar in space. Research on PR retrieval algorithms is important in data application as well as algorithm development. This paper first introduces the PR＇s standard algorithms of radar reflectivity factor retrieval used by NASA and JAXA, and then presents an improved retrieval method. Equivalent raindrop diameter is computed for each radar resolution cell according to its rain rate. If a cell doesn＇t obey Rayleigh scattering condition, the corresponding radar reflectivity factor will be corrected before rain attenuation correction. Qualitative and quantitative comparisons are made on 5 km×5 km×1.5 km grids among ground radar data, PR standard results and the improved results. Results show that the method improves retrieval accuracy at the cost of a small increase in calculation.