迭代法在低纬高原地区多普勒天气雷达测量降水中的应用

 利用昆明多普勒天气雷达资料,采用迭代订正方法对强降水和大范围中等强度降水引起雷达信号的衰减情形进行了订正研究,同时对比分析了衰减订正前后的雷达测量降水与自动雨量站逐小时累计的雨量资料.结果表明:在低纬高原地区雷达测量降水中,强降水和大面积中等强度的降水情况下需要考虑降水对雷达信号的衰减影响;使用迭代法对雷达衰减订正的效果比较好,其订正后的雷达反射率明显高于雷达直接探测的反射率,最大的订正差值超过了9dBz;降水粒子的温度对多普勒天气雷达反射率订正结果也有比较显著影响;订正后雷达测量的降水更接近于自动雨量站的观测值.

Application of iterative technique of attenuation correction to the Kunming Doppler radar

It is corrected that attenuation correction techniques in heavy and big-scale moderate rainfall events,and the comparison analysis between gauge rainfall and estimation of radar rainfall before and after attenuation.The results showed:To the radar rainfall estimates in lower latitude plateau,it should be taken into account the effect of the attenuation coefficients in the heavy or big-scale moderate rainfall events;the method of iterative attenuation correction techniques is a higher accuracy,the radar reflectivity after attenuation corrected is higher compared to the case where the radar measures directly,and the maximum difference of them is over 9 dBz.It is noted that the effect on the values of the corrected reflectivity of the Doppler radar caused by the temperature of the rainfall particles is very evident.At the same time,estimation of radar rainfall after attenuation corrected is closer to atuo-gauge rainfall when compared with radar rainfall before attenuation corrected.