X波段双线偏振雷达回波强度衰减和地物回波识别订正

与常规雷达相比,双线偏振天气雷达在降水系统的准确探测、资料质量的提高等方面具有明显的优势,但X波段双线偏振雷达资料受衰减和地物的影响较大,需要进行必要的衰减和地物订正。本文以2010年7月中国气象局在广东阳江开展的遥感数据比对试验得到数据为例,用ZH和ZDR结合的方法对ZH进行衰减订正,用ZH和ZDR的方差识别地物回波,并利用反射率因子垂直廓线订正受地物影响的底层回波。将订正后的ZH与S波段雷达探测的ZH相比较,将订正后的ZH与KDP的散点图和拟合的KDP与ZH曲线关系对比验证。结果表明经过订正的ZH与S波段雷达探测的ZH一致性较好,与拟合曲线也更为吻合,说明方法能有效提高雷达资料的质量。

Schemes for attenuation correction of radar reflectivity factor, ground clutter discrimination and compensation of a X-band dual-polarization radar

Compared with conventional radar, dual-polarization weather radar has obvious advantages in precipitation system detection, data quality improvement, etc. However, X-band dual-polarization radar data are so easily influenced by attenuation and ground clutter, so that attenuation and clutter corrections are necessary for them. Based on the X-band dual-polarization radar data from the test carried out by China Meteorological Administration in July 2010 in Yangjiang, Guangdong, the attenuation effect on Z_H is corrected by Z_H and Z_DR; ground clutter is identified by the variance of Z_H and Z_DR, and the data combination affected by ground clutter is corrected by the vertical profile of reflectivity factor. In order to verify the effect of corrections, we compared the corrected Z_H with that detected by S-band radar, the scatter plot of Z_H and K_DP after corrections with the fitted curve of them. The results show the corrected Z_H is consistent with that detected by S-band radar as well as with the fitted curve, it means that the methods can improve the quality of the radar data effectively.