A 3D Geometry Reconstruction Method for Space Targets Utilizing Improved ISAR Image Sequence Energy Accumulation

As for space targets with unknown motion, the accurate projection matrix cannot be obtained in advance, which makes the three-dimensional (3D) geometry reconstruction method based on inverse synthetic aperture radar (ISAR) image sequence energy accumulation (ISEA) inapplicable. To tackle this problem, a joint factorization and ISEA-based method is proposed. Firstly, the range-Doppler measurement matrix can be formed through the steadily tracking of a small number of feature points in the ISAR image sequence. Then the factorization method is utilized to estimate the projection matrix, which reflects the projection relationship between the 3D geometry and corresponding ISAR image sequence. Next, when projected to ISAR image sequence, feature points with larger ISEA values can be regarded as the true scattering points on the geometry of the target. Therefore, all the scattering points can be reconstructed by searching the feature points with maximum ISEA values. Experimental results based on simulated point model verify the effectiveness of the proposed method.