Prediction and Evaluation of Active Sonar-System Detection Preformance

Abstract

The concept of signal excess—that is, the excess of signal received over that required for detection—as commonly used in both prediction and evaluation of active sonar-system detection performance is presented. Some of the results of independent measurements of the nominal value and the variability of the various parameters in the signal excess equation are discussed in terms of the deviation of a prediction from the actual evaluation of over-all system performance. Examples are used to demonstrate that the predicted performance will equal the over-all performance as measured for a total system only after recognition and adjustment for parameter interrelationships are made. Acoustic models that have been developed, validated in system tests, and used for active sonar-system performance prediction are shown. Criteria that have been imposed in the measurement of such parameters as source level, receiving sensitivity, propagation loss, interferring noise, and others, are presented together with illustrations of the effectiveness when used. Uncertainties in predicted system performance resulting from parameters and measurements that cannot be controlled or accurately estimated are cited and discussed.