任意沿轨基线长度双孔径SAR-ATI动目标检测方法

MTI method with the along-track baseline of any length based on dual-aperture SAR-ATI

提出了一种适用于沿轨迹排列、任意间距的双孔径天线ATI动目标检测方法,应用于地形高度有起伏的地杂波环境,给出了相应的测速、定位公式。针对在图像域中难以直接实现非整数像素配准的问题,分别在时域和多普勒域中给出了两种解决方法,实现了图像的高精度配准,并在整个观测带内动目标检测的条件下结合聚焦深度的概念给出了具体的实现过程。最后比较了不同波段对该方法的影响,得出了波长越长,测速与定位精度越高,最大可检测不模糊速度提升的结论。仿真结果表明,在不考虑系统噪声的前提下该方法可以实现精确的测速与定位。

An ATI-MTI method is proposed for dual-aperture antenna with arbitrary space interval, which is applied in the condition of uneven terrains with different altitudes, and the velocity measurement and location formula are also proposed. Aimed at overcoming the difficulties brought by the achievement of the sub-pixel coregistration, two solutions in time domain and Doppler domain are proposed respectively, which bring about the high precision of image co-registration. And the realization process is also presented, which combines the condition of MTI in the whole observed terrain and the concept of focus depth. In the end, by comparing the influence of different wave bands on the proposed method, the conclusion is drawn that the velocity measurement and location can achieve a higher precision, and the maximum detectable unambiguous velocity increases with longer wave length. Simulation results demonstrate that this method can realize precise velocity measurement and location regardless of the system noise.