用太阳估测天气雷达天线增益的方法探讨

天线增益是雷达气象方程中的一个重要参数，直接影响天气雷达回波强度的测量精度。分析利用太阳作为信号源测量天气雷达天线增益的可行性，详细介绍了测量原理和方法。利用太阳法测量了一部 C 波段移动式新一代天气雷达的天线增益，并分析了测量误差和提高测量精度的方法。观测试验结果表明，利用太阳测量的天线增益与雷达出厂测试结果接近，精度还有待进一步提高；太阳可用来定期监测天气雷达业务网络中天线的增益变化，有助于及早发现并诊断天气雷达天线指向、馈线损耗、接收机部分存在的故障。

Discussion on antenna gain measurement for weather radar using the sun

Antenna gain is an important parameter in weather radar equation and has a direct influence on accuracy of reflectivity measurement.This paper analyzes the feasibility of antenna gain measurement for weather radar using the sun as a signal source,and introduces relevant principles and methods.Then it measures antenna gain of a C-band mobile China new generation radar (CINRAD)by the sun and analyzes error sources as well as methods to improve measurement accuracy.Observation experiment shows that antenna gain measured using the sun is close to factory test result while measurement accuracy requires further improvement.Therefore,the sun can be used to monitor variation of antenna gain in the operational weather radar network regularly,which is helpful for identifying and diagnosing breakdowns in antenna pointing,feeder line loss and receiver in weather radar system as early as possible.