J. Riley
Defence Sci. & Technol. Organisation, P. O. Box 1750, Salisbury, Australia
R. C. Trider
S. Stergiopoulos
A. T. Ashley
Defence Res. Establishment Atlantic, Dartmouth, NS B2Y 3Z7, Canada
B. G. Ferguson
Defence Sci. & Technol. Organisation, Salisbury, Australia
This experimental paper is concerned with the implementation of the minimum variance distortionless response (MVDR) method [IEEE Trans. 57(8), 1408--1418 (1969)] in a towed array sonar system. The paper discusses the issues associated with the implementation of the MVDR in a real time processing system and examines the robustness of the algorithm using a variety of sea trial data. The performance of an algorithm that pre-processes the data before the MVDR algorithm is applied is also discussed and compared with the standard approach. The experimental results obtained suggest that, as expected, the robustness of the MVDR algorithm is the key to its successful implementation in a real time system. When this condition is met, the MVDR has demonstrated the capability to enhance the conventional beamformer by providing improvements in both angular resolution and detection performance. The implementation of the MVDR algorithm in a real time towed array processing system has necessitated the development of suitable computing architectures that provide the required processing power. A discussion of these developments is also included in the presentation.
Standards Committee S12 on Noise. Working group chairs will report on their progress for the production of noise standards. The interaction with ISO/TC 43/SC1 and ISO/TC 94/SC12 activities will also be discussed, with reference to the international standards under preparation. The Chairs of the respective U.S. Technical Advisory Groups (H. E. von Gierke and E. H. Berger) will report on current activities of these International Technical Subcommittees under ISO and plans for the next meeting of ISO/TC 43/SC1. SCOPE OF S12: Standards, specifications, and terminology in the field of acoustical noise pertaining to methods of measurement, evaluation and control; including biological safety, tolerance and comfort, and physical acoustics as related to environmental and occupational noise.