基于改进时频分析方法的天波雷达机动目标检测算法研究

摘要

在天波超视距雷达(OTHR)中，基于时频分析技术的机动目标检测算法具有信噪比要求低和参数估计精度高等优点。但是传统的时频分析方法计算量大，难以满足实际工程应用需要。针对该问题，该文提出一种新的时频分析方法，该方法构造时间-频率变化率的联合域并沿时间轴进行积分实现机动目标的检测和参数估计。由于该算法积分路径的特殊性，可以避免使用Hough变换，进而减小算法计算量，使其满足实际工程需要。仿真结果表明，该算法在低信噪比(SNR)下检测效果好，运算量低，且具有更高的参数估计精度；此外，该算法对不同时刻的频率变化率成分进行了积累，有效抑制了多机动目标引起的交叉项，避免了虚假目标的出现。%In Over-The-Horizon Radar (OTHR), the maneuvering target detection algorithms based on time- frequency analysis methods have the advantage of low signal to noise ratio requirement and high parameter estimation precision. However, the calculation amount of traditional time-frequency analysis methods is large and it is difficult to meet the requirement of engineering application. To solve this problem, this paper proposes a new time-frequency analysis method by constructing the joint time-frequency rate domain and calculating the integral value along the time axis to achieve maneuvering target detection and parameter estimation. Due to the special integral path, the proposed algorithm avoids the use of Hough transform. It can reduce the computation amount and make it meet the practical requirement. Simulation results show that the algorithm achieves better detection effect in low SNR, lower computation complexity and higher estimation accuracy. In addition, the frequency rate is accumulated according to different time, so it can suppress cross terms caused by multiple maneuvering targets and reduce false alarm rate.