Projects:2018s2-226 Software Library for Inverse Synthetic Aperture Radar

Abstract here

Introduction

Radar monitoring system is now widely used in signal processing and data analysis. With the development of military and civilian fields, detecting targets of a radar are no longer confined to be static, such as flights or ships. Under this situation, a new technique – ISAR – was engendered that uses a static antenna to detect moving targets, whose software library will be developed in this project.

Project team

Project students

• Alfred Lu
• Ting Jiang
• Nan Yang

Supervisors

• Dr Brian Ng
• Dr Hong Gunn Chew

Objectives

The purpose of Project 226: Software Library for Inverse Synthetic Aperture Radar is to write a signal processing software library to form images and implement a variety of algorithms, including converting analogue information into digital data, time and frequency domain analysis, and radar image generation. In addition, all evaluations will be performed in Matlab using both simulated and real data [1].

Background

Radar

Radar works like eyes and ears, however, it is no longer a masterpiece of nature, and its carrier of information is radio waves. In fact, both visible and radio waves, essentially the same thing, are electromagnetic waves, which travels at the speed of light C in a vacuum, differing in their respective frequencies and wavelengths. The principle is that the transmitter of the radar equipment transmits the electromagnetic wave energy to a certain direction in the space through the antenna, and the object in this direction reflects the electromagnetic wave which it meets; the radar antenna receives the reflected wave, then sends it to the receiving equipment for processing, and extracts some information about the object.

SAR

Developed in 1950s, synthetic Aperture Radar (SAR), based on the principle of synthetic aperture, realises high-resolution microwave imaging. It has the characteristics of all-weather, high-resolution and wide-range etc. It was firstly mainly used in airborne and spaceborne platform. With the development of technology, missile-borne, ground-based SAR, UAV SAR, near-space platform SAR and hand-held SAR etc. have appeared. SAR equipped with various forms of platforms is widely used in military and civilian fields.

SAR transmits electromagnetic waves in turn. Radar antenna collects, digitalises and stores reflected echoes for later processing. As sending and receiving occur at different times, they are mapped to different locations. A good combination of received signals has constructed a virtual aperture which is much longer than the physical antenna length. This is why it is called “synthetic aperture”, giving it the attribute of imaging radar. The target direction is parallel to the flight path and perpendicular to the azimuth direction, also known as the orbit direction because it is in line with the position of the object in the antenna’s field of view.

ISAR

Inverse synthetic aperture radar (ISAR) is a radar technique using radar imaging to generate two-dimensional high resolution image pf a target, which is an important branch in the development of SAR. ISAR is capable of imaging long-range targets with high resolution, so it has great potential for long- range targets. To achieve ISAR imaging, motion compensation must be carried out [2].

References

[1] “Project Proposals”, the University of Adelaide, Adelaide, 2018. Available at: https://myuni.adelaide.edu.au/courses/35933/files/3348540/download?wrap=

[2] “Inverse synthetic-aperture radar”, Wikipedia. Available at: https://en.wikipedia.org/wiki/Inverse_synthetic-aperture_radar.