使用加权稀疏恢复的运动声呐混响抑制与低速目标检测
Reverberation suppression and low-speed target detection using weighted sparse recovery for moving sonar
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摘要: 运动平台有源声呐执行非合作目标探测任务时, 目标常被淹没在混响中, 声呐平台运动产生的空时耦合效应会进一步降低运动目标的检测性能; 复杂多变的水下混响和干扰环境难以获得足够的独立同分布训练样本, 导致传统空时自适应处理(STAP)方法性能急剧下降。为此, 提出了一种使用加权稀疏恢复的运动声呐混响抑制与低速目标检测方法, 在压缩感知框架下恢复目标的高分辨空时谱, 实现强混响和噪声背景下低速目标检测及参数估计。该方法仅利用待检测单元数据, 避免了辅助数据或先验知识缺失对混响抑制带来的影响。通过稀疏STAP方法估计权向量并构建加权稀疏优化问题, 在优化过程中实现混响/噪声的抑制和目标的增强。算法设计了低复杂度的优化求解方法, 大大提高了算法的运算效率和实用性。仿真及湖上试验结果验证了该方法的优越性。Abstract: When the active sonar of the motion platform performs non-cooperative target detection tasks, the target is often submerged in reverberation, and the space-time coupling effect generated by the motion of the sonar platform further reduces the detection performance of moving targets. The complex and ever-changing underwater reverberation and interference environment makes it difficult to obtain sufficient independent and identically distributed training samples, resulting in a sharp decline in the performance of traditional space-time adaptive processing (STAP) methods. This article proposes a reverberation suppression and low-speed target detection algorithm using weighted sparse recovery for moving sonar, which restores the high-resolution space-time spectrum of the target in a compressed sensing framework. The algorithm realizes low-speed target detection and parameter estimation in strong reverberation and noisy backgrounds. The data of the range cell to be detected is only utilized to avoid the impact of insufficient training data or lack of prior knowledge on reverberation suppression. The sparse STAP method is used to estimate weight vectors and construct a sparse weighted optimization problem to realize reverberation/noise suppression and target enhancement in the optimization process. A low complexity optimization solving method is designed, which greatly improves the computational efficiency and practicality of the algorithm. The simulation and lake experiment results have verified the superiority of this algorithm.