基于变化趋势约束的毫米波云雷达衰减订正

Attenuation Correction for Millimeter-wave Cloud Radar with Variation Trend Constraint

为减小衰减引起的毫米波云雷达强度数据误差,提出了基于变化趋势约束的衰减订正算法,以小波方法得到的X波段天气雷达反射率因子变化趋势为约束,调整毫米波云雷达反射率因子变化廓线,实现衰减订正。基于实际探测资料的分析和实验表明,较强回波存在时,衰减是造成毫米波云雷达与X波段天气雷达反射率因子差异的主要原因;订正后的反射率因子与X波段天气雷达反射率因子差异减小,相关性增强。基于变化趋势约束的衰减订正方法能够避免常规逐库订正方法因缺乏约束而导致的不稳定问题,减小衰减引起的误差,提升雷达强度数据质量。

To correct the attenuated data of the millimeter-wave radar, an attenuation correction algorithm with variation trend con- straint is presented. The attenuation correction algorithm is implemented by adjusting the reflectivity factors of the millimeter-wave ra- dar using the variation trend of the reflectivity factors of the X-band radar which can be extracted by wavelet method. Experiments on real radar data show that the attenuation is the main reason that causes the difference between the reflectivity factors of the two radars when relatively intense echoes exist. The differences between the corrected reflectivity factors of millimeter-wave radar and the reflec- tivity factors of the X-band radar are reduced and the con＇elations are enhanced. The algorithm can address the instability problem which is inherent in the bin-by-bin algorithm and the quality of the base data of millimeter wave radar is improved after correction.