A Bistatic ISAR Imaging Method of Rectilinear Maneuvering Target

A bistatic inverse synthetic aperture radar (B-ISAR) imaging method is proposed for the rectilinear maneuvering target. According to the idea of the motion decomposition, a B-ISAR echo model is established. By introducing the concept of the equivalent average rotation velocity (EARV), the original sparse imaging algorithm with geometric distortion correction and calibration is extended to the rectilinear maneuvering target. Firstly, both the relationship between the calibration factors and the parameters of B-ISAR system, and the relationship between the geometric distortion and the B-ISAR system and the target motion parameters are deduced. Based on the relationships, the problems of the distortion correction and calibration are transformed into the parameters estimation problem. Then, using the sparsity of scattering points and the maximum a posteriori (MAP) criterion, the parameters are estimated by iterative optimization. After that, the clear ISAR images of the target with geometric distortion correction and calibration is derived. The simulation results show that compared with Range-Doppler (RD) imaging method, the proposed method has better resolution and is more clear with distortion correction and calibration.