Improving target detection in a radar surveillance arrangement

A method of detecting a target in a scene is disclosed. The method involves obtaining a first set of data elements corresponding to returns from different parts of the scene; determining a detection threshold for a part of the scene based on data elements corresponding to returns from neighbouring parts of the scene; obtaining a second set of data elements corresponding only to clutter returns from different parts of the scene and identifying clutter returns in the first data set by comparing the first and second data sets whereby data elements corresponding to clutter are discounted when determining the detection threshold. The data sets may be obtained by processing returns from a radar or lidar system for use in the method. Alternatively the data sets may be written to a storage means for subsequent use in the method. The method may be used in security and surveillance radar applications such that targets close to building, trees and fences may be more reliably detected.