Target track extraction procedure for OLPI antenna data on the basis of Hough transforms

Hough (1962) transformations were developed in order to recognise automatically geometrically describable patterns (especially straight lines) in pictures. This happens by transforming the picture points onto pattern parameters, discretising the parameter space into cells, and registering the number of votes in individual cells. The application of Hough transformations to radar data processing (track extraction) is impeded by the fact that target tracks possess a time-dependent evolution (target velocity). When processing real antenna data, the pure existence of a target track cannot be assumed, and the point of time of its appearance and endurance cannot be predicted. A procedure of recursive radar data processing on the basis of Hough transformations is described. The known partitioned Hough parameter space is, therefore, supplemented by another discretised dimension: the time. Instead of transforming the radar plots themselves, segments of straight lines constructed from two radar plots (eventually belonging to a target track) are transformed onto the extended Hough parameter space. The procedure is able to recognise straight line target tracks. It is applied to real antenna data of the omnidirectional low probability of intercept (OLPI) experimental radar system