海杂波下小目标检测的修正莫利特分布方法

针对雷达在海杂波环境下小目标检测困难的问题,提出了基于修正莫利特( Morlet)分布的检测方法.对海杂波存在目标和没有目标两种情况下进行时频分析,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,时频分布图为较集中且与目标多普勒频移对应的最优曲线.修正Morlet分布检测方法通过邻域最大值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.通过实测数据对固定目标、匀速运动目标和机动目标的仿真表明:与经典CFAR检测方法相比,该方法能够提高海杂波环境下固定目标和机动目标检测性能2～3 dB.

Targets Detection of Sea Clutter Background Based on Modified Morlet Distribution

To improve the radar target detecting performance under sea clutter background,a method based on modified Morlet distribution was presented in this paper.The time-frequency distribution of sea clutter without a target was different to that with a target.The time-frequency distribution without a target was emanative,the time-frequency distribution with a target contained a centralized curve which corresponded to the Doppler frequency shift of target was named optimum curve.The time-frequency distribution method required the optimum curve and took the all points of the optimum curve to judge whether there was a target or not in the sea clutter.Some numerical tests of real data set to the fixed target,moving target on even speed and mobile target proved that this method could promote 2~3 dB of the fixed target and mobile target detection performance under the background of sea clutter compared with CFAR method.