陆地的刚体表面在机载雷达的任意相对运动下具有几何不变性,基于此约束可利用雷达距离像中提取出的地面多个强散射点的一维距离数据,重建出地表的三维信息以及载机未知的运动轨迹。鉴于现有基于雷达远场假设的重建方法无法适用于具有较大近场误差的地面目标重建的问题,提出一种基于雷达近场几何模型的优化重建方法,采用非线性优化方法实现了对重建参数的捆绑调整。仿真结果表明,此算法可使近场目标的重建精度得到显著的提升,由此实现了机载单天线雷达任意未知三维运动下对地表三维信息的高精度几何重构。
Under the arbitrary relative motion of airborne radar, the rigid ground surface holds the geometry invariance. Based on this restriction, the 3D terrain information and the unknown motion path of the carrier-aircraft can be reconstructed using the 1D range data of some strong scatterers extracted from the radar range image. Considering the problem that current reconstruction algorithms based on far-field assumption are incompetent for reconstructing the ground target which involves larger near-field range errors, an optimal reconstruction algorithm based on near-field model of the radar range measurement is proposed and it achieves the bundle adjustment for the reconstructed parameters by utilizing the nonlinear optimization. The simulations verify that, the reconstructed precision of this algorithm is of remarkable improvement for near-field target and, hence, the high precision geometric reconstruction for the terrain’s 3D information under the arbitrary unknown 3D motion of the airborne single-antenna radar is realized.
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