Real-Time Synchronous Integration of Radar and Raingauge Measurements Based on the Quasi Same-Rain-Volume Sampling  

作　　者：万玉发 吴翠红 金鸿祥 

机构地区：[1]Institute of Heavy Rain,China Meteorological Administration [2]Wuhan Central Meteorological Observatory

出　　处：《Acta meteorologica Sinica》2010年第3期340-353,共14页

基　　金：Supported by the Hubei Provincial Key Technology R&D Program(2004AA306B01);the Hubei Provincial International Cooperative Project(2005CA012)

摘　　要：A technique for real-time synchronous integration of radar and raingauge measurements based on the concept of the quasi same-rain-volume sampling（QSVS） is presented.Because of the temporal and spatial discrepancies and resolution differences,the integration of radar measurements with raingauge observations has long been a difficult task.Observations indicate that there exists a correlation that conforms to the power law between hourly accumulated raingauge measurement（Q_G） and detected radar echo（Z_（OH）） over the raingauge.On the basis of this,a concept of the QSVS and five direct correspondent formulas of radar and raingauge samples are built up,aiming to eliminate the temporal and spatial discrepancies.A convenient and practical sampling method—the time integral vertical synchronous sampling（TIVS） is proposed and the Z_（OH）—Q_G relationship is studied.It is significant that under the fixed exponent,the coefficient A_B or A_M varies flexibly in accordance with the temporal and spatial variability of natural precipitation,having the function of synchronously integrating the Z—R conversion and the gauge adjustment into a single equation,and thus the precipitation estimation errors caused by detecting resolution differences between radar and raingauge can be obviously mitigated.The real-time synchronous integration technique using the Z_（OH）—Q_G relationship to estimate the ground hourly rainfall accumulation is called the radar-gauge synchronous integration method（RASIM）.The experiments of two cases show that the accuracy of estimated surface hourly rainfall accumulation within 230 km is about 90%,and the average relative error for the point estimation over the whole process is about 20%. Through the detailed analysis of the applicability of TIVS in three environmental fields with various wind drifts,the physical essence of TIVS is explored：it is an approximate QSVS.By analyzing the data pairs of radar and raingauge,an effective quality-control procedure is established,whiA technique for real-time synchronous integration of radar and raingauge measurements based on the concept of the quasi same-rain-volume sampling（QSVS） is presented.Because of the temporal and spatial discrepancies and resolution differences,the integration of radar measurements with raingauge observations has long been a difficult task.Observations indicate that there exists a correlation that conforms to the power law between hourly accumulated raingauge measurement（Q_G） and detected radar echo（Z_（OH）） over the raingauge.On the basis of this,a concept of the QSVS and five direct correspondent formulas of radar and raingauge samples are built up,aiming to eliminate the temporal and spatial discrepancies.A convenient and practical sampling method—the time integral vertical synchronous sampling（TIVS） is proposed and the Z_（OH）—Q_G relationship is studied.It is significant that under the fixed exponent,the coefficient A_B or A_M varies flexibly in accordance with the temporal and spatial variability of natural precipitation,having the function of synchronously integrating the Z—R conversion and the gauge adjustment into a single equation,and thus the precipitation estimation errors caused by detecting resolution differences between radar and raingauge can be obviously mitigated.The real-time synchronous integration technique using the Z_（OH）—Q_G relationship to estimate the ground hourly rainfall accumulation is called the radar-gauge synchronous integration method（RASIM）.The experiments of two cases show that the accuracy of estimated surface hourly rainfall accumulation within 230 km is about 90%,and the average relative error for the point estimation over the whole process is about 20%. Through the detailed analysis of the applicability of TIVS in three environmental fields with various wind drifts,the physical essence of TIVS is explored：it is an approximate QSVS.By analyzing the data pairs of radar and raingauge,an effective quality-control procedure is established,whi

关 键 词：RADAR RAINGAUGE quasi same-rain-volume sampling（QSVS） synchronous integration hourly equivalent reflectivity 

分 类 号：P414.95[天文地球—大气科学及气象学] TP274.2[自动化与计算机技术—检测技术与自动化装置]