基于EMD和KL变换的时空联合探地雷达杂波抑制

Spatio-temporal combined ground-penetrating radar clutter suppression based on empirical mode decomposition and Karhunen-Loeve transform

探地雷达接收信号中由于环境等原因存在多种杂波干扰,这给地下异常解释与后期成像处理造成很大障碍。杂波主要包括噪声、天线耦合波、地表直达波等,单一的处理方式很难将其有效去除。针对此问题,提出从时间和空间两方面对杂波进行抑制的方法。时间维针对回波剖面中每个测点的数据进行经验模态分解阈值处理,达到对噪声的有效去除。空间维针对整个雷达回波剖面,利用各测点目标回波具有相关性而杂波等随机产生的特点,进行KL变换去除残余干扰。理论仿真及实测数据处理结果均验证了该方法对去杂波以及突出弱信号是有效的。

Due to factors such as environment,the signals received by ground-penetrating radar(GPR)contain various clutter interfer-ence,posing high challenges in subsurface anomaly interpretation and late-stage imaging.Clutter,primarily including noise,antenna-cou-pled waves,and surface direct waves,cannot be eliminated effectively using single data processing methods.Hence,this study proposed a spatiotemporal combined clutter suppression method.In the temporal dimension,threshold processing based on empirical mode de-composition(EMD)was applied to the data of all survey points in the echo profile,achieving effective noise removal.In the spatial di-mension,the Karhunen-Loeve(KL)transform was employed to remove residual interference in the entire radar echo profile by utilizing the correlation of target echoes and the randomness of clutter at all survey points.Both theoretical simulation and measured data process-ing verify that the method proposed in this study is effective in eliminating clutter and highlighting weak signals.