一种机载前视SAR动目标检测方法

A Ground Moving Target Detection Method for Airborne Forward-Looking SAR

当机载雷达接收天线阵面处于前视时,由于接收天线之间没有沿航迹基线,致使已有的基于沿航向基线的合成孔径雷达(SAR)动目标检测方法如DPCA,ATI方法无法应用。此外,由于在前视条件下地杂波的多普勒频率与空间角频率呈现非线性关系,从而给地面运动目标的检测带来困难。针对该问题提出了一种机载前视阵雷达SAR地面运动目标检测定位方法,该方法在短脉冲条件下利用降维空时自适应处理(STAP)技术对杂波进行抑制,然后采用最优波束形成方法对动目标进行径向速度搜索。该方法能够实现在前视SAR条件下的地面动目标检测。仿真实验结果验证了该方法的有效性。

The along-track baseline won＇t exist between the received channels for airborne forward-looking radar. As a result, the methods based on the along-track baseline, such as displaced phase center antenna （DPCA） and along-track interferometry （ATI）, cannot achieve excellent clutter suppression perform- ance. Moreover, because the Doppler frequency and the spatial angle frequency of the clutter present nonlinear relation, the clutter cannot be suppressed. A short-pulse SAR based three-channel ground moving target detection method is proposed for forward-looking airborne radar. The receiving antenna is dispersed larger than the wave length. EFA STAP is introduced to suppress the clutter, and then the radial velocity is searched by CAPON beamforming. Simulation results show the validity of the proposed method.