基于深度学习的非合作双基地雷达目标检测方法
A Non-cooperative Bistatic Radar Target Detection Method Based on Deep Learning
-
摘要: 非合作双基地雷达由于接收的目标信号能量不强且回波脉冲间相位同步困难,在目标检测时无法进行相参处理从而带来弱小目标检测困难的问题。为解决这一问题,本文把一维雷达数据转换成二维图像数据进行目标检测,通过将脉冲压缩后的雷达回波在慢时间维排列形成二维矩阵,获得雷达回波信号的距离-慢时间图像,输入YOLO(you only look once)v5s网络进行特征学习,实现非合作双基地雷达目标智能化检测。针对距离-慢时间图像中待检测目标的不显著性以及受到背景信息干扰严重的问题,本文对YOLOv5s网络进行改进:首先在Neck部分增加跨连接通路,使训练过程中持续有原始信息的参与;其次通过添加注意力机制SENet模块,加强网络对目标以及周边信息的关注度;最后在骨干网络引入Swin Transformer模块,加强网络对弱目标的发现与表征能力。然后,基于上述工作提出一种基于改进的YOLOv5s距离-慢时间图像处理的非合作双基地雷达目标检测方法。通过大量的对比实验和信噪比灵敏度测试实验,该方法在仿真的雷达回波数据集上获得了99.1%的检测精确度以及98.8%的召回率,比YOLOv5s网络分别提高了4.5%和4.2%,表明该改进方法能有效提高YOLOv5s网络检测性能;对于脉冲压缩后信噪比为7.1 dB的目标,检测率达到98.5%,传统方法的检测概率仅为79.9%,表明本文所提方法能有效提高目标检测的准确率和信噪比灵敏度,具有较强的应用价值。Abstract: Non-cooperative bistatic radar target detection usually encountered the problem of weak target detection caused by the weak energy of the received target signal and the difficulty of phase synchronization between echo pulses. To solve this problem, in this paper, we transformed one-dimensional radar data into two-dimensional image data for object detection. The range-slow time image of the radar target is obtained by arranging the pulse compressed radar echo along slow time dimensions. Then the range-slow time images are employed by the YOLO(you only look once)v5s network for feature learning to achieve intelligent detection of non-cooperative bistatic radar targets. Regarding the non-significance of the target to be detected in distance-slow time images and the serious background interference, this paper improved the YOLOv5s network: firstly, the cross-connection pathway is added to the Neck section to ensure the continuous participation of the original information in the training process; secondly, the attention mechanism SENet module is added for strengthening the network’s attention to the target and peripheral information; finally, the Swin Transformer module is introduced in the backbone network to enhance the discovery and characterization of weak targets. Then on the basis of the above work, we proposes a non-cooperative bistatic radar target detection method based on improved YOLOv5s which uses range-slow time image as input. Through numerous of comparative experiments and SNR sensitivity testing experiments, this method obtained 99.1% detection accuracy and 98.8% recall rate on the simulated radar echo data set, which was 4.5% and 4.2% higher than YOLOv5s network, indicating that the improved method can effectively improve the detection performance of YOLOv5s network; and for the target with a 7.1 dB signal to noise ratio of pulse compressed radar echo, the detection rate reaches 98.5%, and the detection probability of the traditional method is only 79.9%, indicating that the proposed method can effectively improve the accuracy and sensitivity of target detection, and has strong application value.