Eigenspace-Based Motion Compensation for ISAR Target Imaging

Abstract

A novel motion compensation technique is presented for the purpose of forming focused ISAR images which exhibits the robustness of parametric methods but overcomes their convergence difficulties. Like the most commonly used parametric autofocus techniques in ISAR imaging (the image contrast maximization and entropy minimization methods) this is achieved by estimating a target's radial motion in order to correct for target scatterer range cell migration and phase error. Parametric methods generally suffer a major drawback, namely that their optimization algorithms often fail to converge to the optimal solution. This difficulty is overcome in the proposed method by employing a sequential approach to the optimization, estimating the radial motion of the target by means of a range profile cross-correlation, followed by a subspace-based technique involving singular value decomposition (SVD). This two-stage approach greatly simplifies the optimization process by allowing numerical searches to be implemented in solution spaces of reduced dimension.

Joint inference of dominant scatterer locations and motion parameters of an extended target in high range‐resolution radar

“…Since the motion of the target centroid is severely constrained on the time scale which is considered here, a simple almost constant velocity motion model [24] would suffice. Furthermore, motion compensation algorithms exist which could remove the velocity component of an can be found in [5, 25–28]. The method presented in this paper can be extended using the state augmentation approach or any of these motion compensation algorithms, but falls beyond the scope of this paper.…”

Facet Model of Moving Targets for ISAR Imaging and Radar Back-Scattering Simulation

“…Nevertheless, this information can be useless if the target motion produces blurred images. Motion compensation algorithms [4][5][6][7][8] or time-frequency techniques [9][10][11][12][13][14][15] are useful techniques to solve this problem.…”