X波段双极化雷达在北京夏季降水估测中的应用

Application of X-Band Dual Polarization Radar in Precipitation Estimation in Summer of Beijing

利用X波段双极化雷达和地面自动雨量站数据对北京地区2009年夏季降水进行分析,先采用低通滤波、衰减订正等方法对数据质量进行控制,提取了单位差分传播相移Kdp之后,分别拟合出X波段双极化雷达参数与降水之间的两个关系式:Zh=159R1.37及R=13.9Kdp0.81,最后再分别利用这些拟合公式对北京地区进行降雨估测。结果表明:雷达用这两个公式估测的降雨量与地面实测降雨量有较好的一致性;且当每小时降雨量大于10mm时,Kdp-R的估测比Zh-R估测更稳定、准确;通过平均标准差统计可知,Kdp-R估测精度明显高于Zh-R估测精度。

Dual polarization X-band radar data and ground-based automatic rain gauge data were analyzed for precipitation estimation in summer of Beijing in 2009. Firstly, the low pass filtering and attenuation correction methods were used for controlling the quality of radar data. Then two relationships of X-band radar parameters and rain rate were established, i.e. Zh = 159R137 and R = 13. 9Ksl, after the specific differential propagation phase （Kdp） was extracted. Finally the comparison analysis was made between the rain rates estimated from the two relationships and the corresponding ground data. The results indicate that the rain rates estimated from the two relationships have a good consistency with the ground data. In addition, when the rain rates are greater than 10 mm ·h-1 , the esti- mated rain rates from Kdp-R are more accurate and stable than that from Zh-R. Also, the average standard devia- tion analysis shows that the estimation accuracy of Kdp- R is significantly higher than Zh- R.