结合稀疏贝叶斯学习的快速运动目标方位估计方法
Azimuth estimation of fast-moving targets based on sparse Bayesian learning
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摘要: 采用长时多快拍数据对快速运动目标(指方位快速变化)进行方位估计时, 传统的方位估计方法通常假设目标方位在多个快拍时间内保持不变, 但这会导致目标方位偏差, 或产生伪峰, 从而将虚假目标当成潜在目标, 做出错误判断。为解决这一问题, 并获得多快拍下的时间增益, 提出了一种基于稀疏贝叶斯学习的快速运动目标多快拍方位估计方法。与传统方法不同, 所提方法的信号模型不再假定目标方位在多个快拍时间内保持恒定, 而是引入了方位变化率这一未知参数, 通过构建目标运动情况下的多快拍阵列导向向量来更准确地描述目标的运动状态。随后采用稀疏贝叶斯学习方法对每个目标的初始方位角和方位变化率进行联合估计。数值仿真结果显示, 对于有多目标运动的场景, 该方法相较传统的稀疏贝叶斯学习算法具有更高的方位估计精度。海试数据处理结果也表明, 在长时多快拍处理情况下, 该方法能更准确估计目标方位轨迹, 具有更好的方位分辨能力。Abstract: When estimating the azimuth of fast-moving targets using long-term multiple snapshot data, traditional methods assume a constant azimuth for the target throughout the processing of multiple snapshots, which may lead to azimuth deviations or the emergence of false peaks, resulting in the misidentification of non-existent targets. To address this issue, this paper proposes an azimuth estimation method for fast-moving targets based on sparse Bayesian learning. Unlike conventional methods, the proposed approach does not assume a constant azimuth across multiple snapshots. Instead, it incorporates an unknown parameter to characterize the azimuth change rate. This is achieved by constructing multi-snapshot array steering vectors that more accurately model the dynamic motion state of the target. Sparse Bayesian learning is then employed to jointly estimate both the initial azimuth and the azimuth change rate for each target. Numerical simulations show that, the proposed method significantly improves the accuracy of azimuth estimation in scenarios with multiple moving targets compared to traditional sparse Bayesian learning algorithms. In addition, results derived from the processing of experimental sea data indicate that this method effectively estimates target azimuth trajectories in long-term multi-snapshot scenarios and exhibits excellent azimuth resolution capabilities.