Detection of Growlers in Sea Clutter Using an X-band Pulse-Doppler Radar

Abstract

<p>Safe navigation of vessels though ice-infested waters in the Canadian Arctic and along the East and West Coasts of Canada is of vital importance to the exploration and development of natural resources. Current marine radar technology performs poorly in distinguishing first year ice from multiyear ice and in detecting small ice fragments (called growlers) in open water. Previous studies by the Communications Research Laboratory, McMaster University have been successful in developing improved classification techniques for first year and multiyear ice using an X-band radar. This thesis aims to provide improved detection techniques of small ice targets in open water. With the recent go ahead of the Hibernia Project (a large oil-drilling project off of the coast of Newfoundland), the problem of reliable detection of growlers with a ship-based radar has become even more critical. In this thesis, improved growler detection capabilities are presented. These results are based upon a detailed study of sea clutter and growler data obtained with the use of a dual-polarized, pulse-Doppler, X-band radar known as IPIX. Several contributions have resulted from the collection and analysis of real radar returns from growlers and the sea. We show that the amplitude statistics of sea clutter are K-distributed, and we quantify the poor performance that results in this non-Rayleigh clutter. Furthermore, we show that significant performance improvements can be obtained by exploiting the time-varying Doppler signatures of growlers in sea clutter. Several medium dwell-time coherent detectors are designed and their performances evaluated and presented in the form of receiver operating characteristics (ROC). Finally, the comparative advantages and tradeoffs of these detectors are considered in detail.</p>