Aspects of NCTR for Near-Future Radar

This paper considers a number of aspects related to the achievement of non-cooperative target recognition capabilities in current and near-future radar systems. The scope of the paper is restricted to consideration of the use of high range-resolution profiles. Three particular aspects are discussed. Firstly, the problem of achieving a high range-resolution capability on radars which typically have only narrow instantaneous bandwidths is considered; an approach is described in which the usual shortcomings associated with step-frequency waveforms are avoided. Secondly, the consequences of having less than ideal performance from the radar system are considered. The loss in classification performance which occurs when returns are degraded in terms of resolution and signal-to-noise ratio are described. The results given apply to civil aircraft and compare performance from a feature-matching and a profile-correlation algorithm. The third aspect considered relates to the nature of the classifier itself. There are numerous choices to be made; we discuss what data should be used for classification, sources of reference data for classifiers and different types of classification algorithm. A focus is placed on the representation of reference data as a scattering centre model of each aircraft of interest; such a model attempts to give an abstract representation of key features in a form which may incorporate both radar and non-radar data, and which is not particular to any one radar system.