三通道SAR-GMTI地面快速目标检测

地面运动目标速度较大时,会产生距离徙动,在图像域出现严重散焦,不易检测;同时存在PRF模糊现象,其多普勒频谱会发生折叠,不易正确定位。针对上述问题,提出了基于机载三通道SAR-GMTI的地面快速目标检测、定位与成像方法。首先,在距离压缩后的数据域进行相位中心偏置天线(displaced phase center anten-na,DPCA)杂波抑制,组合运用Canny算子、Ratio算子和Hough变换提取快速目标运动轨迹。然后,采用基于解PRF后的二阶Keystone变换方法完成目标的成像、检测及运动参数估计。最后,将快速目标融合到标有慢速运动目标的清晰SAR图像中。外场实测结果验证了该方法的有效性和准确性。

Ground fast moving target detection based on tri-channel SAR-GMTI

Usually,the range migration through resolution cells which results in an image badly unfocused makes fast moving target hardly detect.Additionally,PRF ambiguity which results in Doppler spectrum folded strongly impairs accurate position. A method for ground fast-moving target detection,position and imaging based on the tri-channel airborne SAR-GMTI is presented in case of the problems above.Firstly,DPCA is used for clutter suppression when implemented on range compressed and azimuth-uncompressed data.The Canny operator,ratio operator and Hough transform are combined to extract the moving tracks.Then a method based on two-order Keystone transform after resolving PRF ambiguity is used for target imaging,detection and motion parameter estimation.Finally,the slow and fast-moving targets are together labeled on the SAR image.The results on raw data show the efficiency of the proposed method.