一种FFT分频道+低通滤波的主杂波自适应估计方法  

An adaptive mainlobe clutter estimation method combining FFT channelization and low-pass filtering

作　　者：郭晓乐 武正翔 王金峰[1,2] GUO Xiaole;WU Zhengxiang;WANG Jinfeng(No.38th Research Institute,China Electronics Technology Group Corporation,Hefei 230088,China;Key Laboratory of Aperture Array and Space Application,Hefei 230088,China)

机构地区：[1]中国电子科技集团公司第三十八研究所,合肥230088 [2]孔径阵列与空间探测安徽省重点实验室,合肥230088

出　　处：《空天预警研究学报》2025年第2期93-98,共6页JOURNAL OF AIR & SPACE EARLY WARNING RESEARCH

摘　　要：机载雷达在照射背景中存在大量孤立强点时,按照传统的主杂波估计方法会错误地将孤立强点估计成主杂波频率.为了正确地估计主杂波频率,提出基于低通滤波的主杂波自适应估计方法.首先对接收到的脉冲信号在距离单元维进行脉冲压缩处理;然后对脉压后的信号在脉冲维进行快速傅里叶变换(FFT)处理,针对滤波后的信号在距离单元维做分段处理,在各个频道上分别取分段中求和值最小值作为当前频道的FFT滤波估计值;之后对估计值进行低通滤波,结果按照一定的比例只保留数据的低频成分;最后利用保留低频成分高频置零的数据恢复出不含孤立强点的多普勒分布曲线,恢复后的数据最大值对应的多普勒频率即为主杂波对应的多普勒频率.实测结果表明,与传统方法相比,本文方法估计出的主杂波多普勒频率误差更小,能准确地获得系统的主杂波频率.When airborne radar illuminates the background containing a large number of isolated strong points,traditional mainlobe clutter estimation methods may erroneously identify these isolated strong points as the main clutter frequency.In order to accurately estimate the main clutter frequency,an adaptive mainlobe clutter estimation method based on low-pass filtering is proposed.First,the received pulse signals are processed with pulse compression along the range bin dimension.Then,a fast Fourier transform(FFT)is performed on the pulse-compressed signals along the pulse dimension;the filtered signals are segmented along the range bin dimension,and the minimum mean value of the segment selected in each channel is taken as the FFT filter estimation value for the current channel.Subsequently,the estimated values are subjected to low-pass filtering,retaining only the low-frequency components of the data according to a certain ratio.Finally,the data with retained low-frequency components and high-frequency zeroed are used to reconstruct the Doppler distribution curve without isolated strong points.The Doppler frequency corresponding to the maximum value of the reconstructed data is identified as the Doppler frequency of the main clutter.The result of actual measurement demonstrates that,compared with traditional methods,the proposed method achieves a smaller estimation error in the main clutter Doppler frequency,thus enabling more accurate acquisition of the system’s main clutter frequency.

关 键 词：机载雷达 孤立强点 主杂波 低通滤波 

分 类 号：TN958[电子电信—信号与信息处理]