风廓线雷达回波信号强度定标方法  

Calibration Method of Echo Intensity of Wind Profile Radar

作　　者：钟刘军[1,2] 阮征[2] 葛润生[2] 陈钟荣[1] 任京伟 沈祥林 张哲 魏艳强 

机构地区：[1]南京信息工程大学,南京210044 [2]中国气象科学研究院灾害天气国家重点实验室,北京100081 [3]中国航天科工集团第二十三研究所,北京100854

出　　处：《应用气象学报》2010年第5期598-605,共8页Journal of Applied Meteorological Science

基　　金：国家自然科学基金项目(40675019;41075023);科技部公益性行业专项"风廓线雷达数据处理算法和产品研发"(GYHY200906039);灾害天气国家重点实验室自主研究项目"多种探测技术的应用研究"共同资助

摘　　要：风廓线雷达返回信号功率定标通常通过返回信号信噪比和系统噪声功率的估算得到。该方法存在着噪声电平的确定、外部噪声等不确定性因素,影响了定标的精度。采用信号源分别对接收机和信号处理器进行定量测试,进而对雷达系统进行定标,是另一种可行的办法,该文利用这种方法对CFL-03风廓线雷达进行了定标,并利用该雷达在东莞2009年7月和8月探测资料与广州S波段天气雷达和地面雨量计资料进行比较。结果表明:用该定标方法得到的回波强度与天气雷达回波强度和地面雨量计资料估算的回波强度基本一致,平均标准差在1 dB左右,表明这种定标方法是可行的。A lot of researches about wind profile radar are based on analysis of echo power.So the estimation accuracy of echo power has direct effects on the use and expansion of wind profile radar data.At present,return signal power of wind profile radar is estimated by signal to noise ratio（SNR） and radar system noise power.Environmental noise may cause errors when estimating SNR in power spectrum of wind profile radar, affecting calibration accuracy.Another viable option is quantitatively testing the receiver and signal processor respectively using the same signal source,and then the calibration curve of radar systems can be determined according to the measured signal processor linear curve.Using this method,the calibration curve of CFL-03 wind profile radar is determined,and probe data of the radar in July and August,weather radar data and surface rain gauge data are compared.The results show that the weak signal of wind profile radar can be calibrated effectively,on the basis of measurement of the coherent accumulation and pulse compression accumulation using intermediate frequency source.The method proves feasible through the actual test.And through field experiments it can be seen that calibrated echo intensity of wind profile radar and SA weather radar echo intensity are basically the same with an average error less than 2 dB,within the scope of weather radar calibration error.The errors between calibrated echo intensity of wind profile radar and ground rain gauge data is less than 2 dB,indicating that the calibration results are credible.

关 键 词：风廓线雷达 定标 噪声电平 信噪比 回波功率 

分 类 号：P415.2[天文地球—大气科学及气象学]