基于时频分布的海杂波环境下目标检测

对海杂波存在目标和没有目标两种情况进行时频分析,其时频分布图表现出明显的特征差异,在没有目标时,时频分布图比较发散,存在目标时,时频分布图中有较集中且与目标多普勒频移对应的最优曲线。利用这种差异,文章提出了基于时频分布的目标检测方法。时频分布检测方法通过查找算法得到该最优曲线,并取该最优曲线所有点的和值作为判断目标存在与否的依据。通过实测数据仿真表明该方法能够提高海杂波环境下目标检测性能。

Targets Detection in Sea Clutter Based on Time Frequency Distribution

This paper presents a small targets detection method based on the difference of time-frequency distribution between sea clutter with or without a target.The key point of this method is searching the optimum curve in time-frequency distribution,i.e.the most possible curve corresponding to the Doppler frequency-shift of a target.First select a start-point,find out the maximum value at a certain frequency range from right or left of this point.Then take the new point as the start-point,find out the next point,until all the point finished,and all points form a curve.After all curves finished,summate all points of every curve and the maximum one is the best curve.Last compare the maximum value against the threshold,if the result is larger,it is a target,otherwise it is clutter.Some numerical tests of real data sets prove that this method can improve the detection performance of a small target in sea clutter obviously.