Application of Scaling in Radar Reflectivity for Correcting Range-Dependent Bias in Climatological Radar Rainfall Estimates
Application of Scaling in Radar Reflectivity for Correcting Range-Dependent Bias in Climatological Radar Rainfall Estimates
复制标题
应用雷达反射率缩放来校正气候雷达降雨估算中的距离相关偏差
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
Ashish Sharma
中科院分区：
文献类型：
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作者：
S. Chumchean;A. Seed;Ashish Sharma
摘要本文提出了一种修正雷达反射率距离相关偏差的方法，这种偏差是部分波束填充和观测量随距离增加而增加的结果。本研究探讨了反射率场随雷达距离变化的标度行为。结果发现，一个简单的缩放范例是适用的，并提出了一个尺度转换函数，以确保在近距离和远距离的反射率的概率分布的均匀性。幂律变换函数的标度指数是利用来自澳大利亚悉尼1° C波段和1.6° S波段雷达的笛卡尔网格中的6个月反射率图序列和极坐标中的两组瞬时反射率图估计的。将瞬时极坐标反射率转换为逐时笛卡尔网格数据的平均过程导致逐时笛卡尔反射率数据的标度指数比瞬时平面降水数据的标度指数低。
Abstract This paper presents a method to correct for the range-dependent bias in radar reflectivity that is a result of partial beam filling and of the increase in observation volume with range. The scaling behavior of reflectivity fields as a function of range from the radar was explored in this study. It was found that a simple scaling paradigm was applicable, and a scale transformation function was proposed to ensure uniformity in the probability distributions of reflectivity at both near and far range. The scaling exponents of the power-law transformation function were estimated using a 6-month sequence of reflectivity maps in a Cartesian grid and two sets of instantaneous reflectivity maps in polar coordinates from 1° C-band and 1.6° S-band radars at Sydney, Australia. The averaging process that transforms the instantaneous polar reflectivity into the hourly Cartesian grid data leads to a lower scaling exponent of the hourly Cartesian reflectivity data compared with the instantaneous plan precipitati...