Evaluation of noise and clutter induced relocation errors in SAR MTI

Abstract

A synthetic aperture radar (SAR) is a side looking airborne radar designed to produce two dimensional high resolution radar images. Moving targets are displaced in azimuth on a SAR map. A separate SAR-MTI process is therefore used for the detection and relocation of moving targets. Errors in estimating the angular positions of the detected moving targets are referred to as relocation errors. A two port interferometer antenna whose baseline lies along the flight direction allows the detection of slow moving targets that are otherwise masked by main lobe clutter. A model for evaluating relocation errors in a two port interferometer SAR-MTI scheme is developed. The effects of various parameters such as aircraft speed, antenna beamwidth, squint angle, radar PRF and the target to noise and clutter ratios are evaluated.