Simulated annealing CFAR threshold selection for South African ship detection in ASAR imagery

Abstract

Synthetic Aperture Radar images are able to detect ships that would be hidden to tradition ship tracking methods due to their transponders being turned off. Using a SAR image as input, the CFAR method can highlight these ships given a correctly chosen threshold value. Typically, the threshold value is chosen as a single floating value for all positions creating a flat threshold plane. This study introduces a novel method of creating a threshold plane which is adapted using Simulated Annealing. This non-flat threshold allows different areas of the image to have different threshold values thereby improving the overall performance of the ship detection system. It was found in our experiments that the proposed method improves upon the false alarm rate of the flat threshold plane CFAR method whilst keeping a similar level of detection accuracy.