# Wavenumber-Domain Joint Estimation of Rotation Parameters and Scene Center Offset for Large-Angle ISAR Cross-Range Scaling

## TL;DR

This paper presents a new method for improving ISAR cross-range scaling by jointly estimating rotation and scene center offset in the wavenumber domain.

## Contribution

A novel joint estimation method combining PSO and image entropy for accurate ISAR cross-range scaling.

## Key findings

- A non-uniform rotational wavenumber-domain signal model with SCO was developed.
- The proposed method achieves higher accuracy in ISAR cross-range scaling than traditional methods.
- Validation through simulations shows the method's effectiveness and robustness under various conditions.

## Abstract

While the wavenumber-domain approach enables large-angle inverse synthetic aperture radar (ISAR) cross-range scaling, its practical application remains constrained by the target’s non-uniform rotation and scene center offset (SCO). In response to this issue, this paper introduces a novel large-angle ISAR cross-range scaling method through a joint estimation method based on the wavenumber domain. A non-uniform rotational wavenumber-domain signal model with SCO is developed. Utilizing this model and the sensitivity of wavenumber-domain imaging to SCO, a joint estimation algorithm that combines particle swarm optimization (PSO) and image entropy evaluation is proposed, achieving accurate parameter estimation. Leveraging the estimated parameters, the range and cross-range scaling factors in the wavenumber-domain imaging are derived, facilitating ISAR cross-range scaling with higher accuracy than the traditional method. The effectiveness and robustness of the proposed method are validated under various conditions, through scattering point and electromagnetic computing simulation.