基于InISAR技术的三维成像

3D image reconstruction using the InISAR technique

建立了在目标与天线电轴间存在较大斜角情况下的干涉式逆合成孔径雷达(InISAR)三维成像模型.研究了目标运动补偿误差对干涉测量的影响,并给出运动补偿的详细步骤.由于相位差以2π为周期,所以运动补偿误差对测量结果的影响也是周期性的,这可能造成目标像的横向折叠,本方法首先估计出目标像重心相位,然后将目标像重心作为目标的基准点对相位差进行补偿以校正目标的偏移.测量得到的目标三维坐标并不是在直角坐标系下得到的,给出了坐标转换的公式.最后用仿真结果验证了此方法的有效性.

The model of the interferometric inverse synthetic aperture radar （InISAR） three-dimensional imaging is proposed when the angle between the target and the antenna axis is relatively large. The measurement error induced by the motion compensation error is discussed in detail and the motion compensation scheme is presented. Because the phase difference is 2n-periodic, the influence of the motion compensation error on the mearsurement result is also periodic, which may cause the ambiguity of the image in the cross-range. In this method, the phase of the image＇s barycentre is estimated, and then the barycentre is used as a reference for compensating the phase diferrence for the correction of the target＇s cross-range shift. The scatterers＇ height and width measured are not the correct coordinates of the target because they are not obtained in rectangular coordinates. The formula for transforming the measured coordinates into rectangular coordinates and generating a correct 3D image is given. Finally, the simulation results are given.