CINRAD/SB雷达回波强度定标调校方法

The Method of CINRAD/SB Radar Echo Intensity Calibration and Adjustment

回波强度定标和调校方法是保障CINRAD/SB回波强度测量精度的关键技术,方法不当会导致回波强度测量误差增大,直接影响雷达定量估测降水产品的可靠性。为了满足回波强度测量误差在±1 dBZ范围内的技术要求,根据雷达气象方程,通过对CINRAD/SB接收机测试通道、主通道、天馈系统相关影响回波强度测量误差的因素进行分析,提出了从接收机动态范围和雷达参数调整、线性通道增益定标目标常数定标,到测试通道参数调整的回波强度定标工作流程。总结出以线性通道增益定标目标常数定标为基准,采用测试通道参数测量法或基准法调校,以保证发射功率和接收机动态范围变化导致的回波强度测量误差得到在线实时校正,提高了CINRAD/SB回波强度测量精度。从接收机测试通道、主通道、天馈系统及发射功率4个方面,给出了回波异常的分析和诊断流程。并提出在接收机保护器前端增加机外信号注入口和定标信号功率检测功能,以利于机内外回波强度定标对比校准和消除测试通道参数变化导致回波强度测量误差的建议。

CINRAD echo intensity calibration is the key technology to improve the reliability of observational data. Improper intensity calibration adjustment method or mishandling of the alarm can lead to large measurement error.Based on test procedure of CINRAD/SB radar signal and the principle of echo intensity calibration, the work discipline of echo intensity calibration is established.The related parameter measurement, calibration and adjustment methods are introduced,clarifying receiver dynamic range,radar parameters, the line channel target syscal constant,test channel parameters.To meet the receiver＇s dynamic range,parameter measured adjustment method or the standards method is applied and the line channel target syscal constant calibration is considered.These methods ensure that echo intensity measurement error caused by changes of transmit power and receiver dynamic range is calibrated with real-time corrected echo intensity data,and the technical requirements for controlling echo intensity measurement error range within±1 dBZ are met.The mechanisms through which receiver test channel parameter change and transmit power measurement error lead to the echo intensity measurement error are also discussed in detail.Calibration problem diagnosis and treatment process of CINRAD/SB radar echo intensity are illustrated based on relevant alarms of echo intensity calibration and echo display information,combining the receiver test channel,main channel and the antenna feeder system,transmission power.The imperfections and improving method of CINRAD/SB echo intensity calibration technique is explored to provide reference and tech-nical support for new generation of weather radars.