Radon变换的雷达低慢小目标检测方法

Radar Detection Method for Low-Altitude Slow and Small Target Based on Radon Transform

近年来,由于军民领域应用需求的爆发增长,以无人机和轻型直升机等为代表的低空慢速小目标得到了迅猛发展。与此同时,由于此类目标具有"飞行高度低、飞行速度慢以及散射截面积小"等特点,目标回波常常淹没于强地/海杂波中且在频域与慢速杂波混叠严重,致使基于频域滤波的传统检测技术难以对其有效探测,这为防空预警雷达带来了新的严峻挑战。首先在综合考虑了多路径干涉、大气衰减以及系统损耗等因素的情况下,构建了雷达"低慢小"目标回波模型,然后在通过Kalmus滤波器进行强杂波抑制的基础上,对长时间观测下的多帧雷达回波数据所合成的距离-慢时间像进行慢时间域降维平滑处理,最后结合Radon变换,在变换后的参数域通过设置门限完成目标检测,实验仿真结果表明了该方法的有效性。

In recent years,due to the emergence of military and civilian applications of the outbreak of growth,the unmanned aerial vehicles and light helicopters as the representative of the low-altitude slow small target has been rapid developed. Because such targets have the characteristics of ＂low flying altitude,slow flight speed and small RCS ＂,the target echo is often submerged in the strong ground/sea clutter. The traditional detection technology based on the frequency domain filtering is difficult to detect,which brings new serious challenge for the air defense early warning radar. To solve the problem,the multi path interference,atmospheric attenuation,system loss and other factors,the construction of the target echo model are considered; based on the strong clutter suppression by Kalmus filter,the distance and slow time image of the multi-frame radar echo data under long term observation is simulated by the slow time domain. After combining with the Radon transform,the target detection is completed through the threshold setting of the transformed parameter field. The experimental results show the effectiveness of the proposed method.