Multistatic synthetic aperture radar autofocus for back projection imaging of a moving target

Date published

2025-01

Free to read from

2025-03-28

Supervisor/s

Journal Title

Journal ISSN

Volume Title

Publisher

Institution of Engineering and Technology (IET)

Department

Type

Article

ISSN

0013-5194

Format

Citation

Rattan A, Andre D, Finnis M. (2025) Multistatic synthetic aperture radar autofocus for back projection imaging of a moving target. Electronics Letters, Volume 61, Issue 1, January/December 2025, Article number e70217

Abstract

Synthetic Aperture Radar (SAR) plays a vital role in the surveillance of terrestrial and maritime targets, which are commonly in motion. As such, the ability to perform accurate real‐time focusing and localisation on moving targets, particularly those moving with complex motion, is desired. Many existing autofocus algorithms struggle to achieve this and rely on sub‐aperture processing of SAR data to estimate and compensate for phase errors attributed to unknown target motion. This paper presents a new metric‐based autofocus approach, called Localised Threshold Sharpness (LTS), which employs multistatic SAR data to localise and focus a target moving with up to six degrees of freedom motion on a real‐time, pulse‐by‐pulse basis. The algorithm is verified with experimental data, and its performance is compared against the performance of an existing measure of image sharpness suitable for pulse‐by‐pulse autofocusing, namely the intensity‐squared metric, with varying levels of added noise. Normalised cross‐correlation results demonstrate a resemblance of at least 80% between Multistatic SAR images focused via LTS autofocus and Multistatic SAR images ideally focused using target motion knowledge for signal‐to‐noise ratios above 3 dB.

Description

Software Description

Software Language

Github

Keywords

4013 Geomatic Engineering, 40 Engineering, Electrical & Electronic Engineering, 4006 Communications engineering, 4009 Electronics, sensors and digital hardware, motion compensation, motion estimation, radar imaging, radar target recognition, sonar and navigation, synthetic aperture radar, target tracking

DOI

Rights

Attribution 4.0 International

Relationships

Relationships

Resources

Funder/s

This work was funded by Defence Science and Technology Laboratory.