Extended Target Three-Dimensional Reconstruction From Inverse Synthetic Aperture Ladar Image Sequence

Abstract

Inverse Synthetic Aperture Ladar (ISAL) can continuously capture images of the target in complex motion, which provides an opportunity for the 3-D reconstruction. However, the existing 3-D imaging methods need to meet some specific conditions, including multiple isolated prominent scattering points in the image, known or parametric motion of the target, and 360° observation of the target. To relax these restrictions, a novel 3-D reconstruction method is proposed. In this method, the corner of the target is first detected and used as a reference point. Then, the positioning accuracy of these fiducial points is greatly improved by the relationship between the radial range and velocity. Finally, the 3-D reconstruction is realized by the singular value decomposition of the measurement matrix. The data obtained from the outdoor experiment are used to test the proposed method. By this process, a series of images of a satellite model which is 2 km away are acquired. The size and shape errors of the reconstruction are less than 10%. The result demonstrates the effectiveness of the 3-D reconstruction method.