Evaluating search effectiveness using a combination of modeled and measured data

Since 1992, the Navy has used a performance prediction system that combines measured and modeled active and passive total interference with modeled transmission loss to automatically compute probability of detection (POD) at regular intervals and display the results in a geographic reference frame. A limitation of such a display is the inability of the sensor operator to determine the cumulative sensor performance over time, or to evaluate the combined effect of multiple sensors. A new program, written to overcome these limitations, ingests instantaneous probability of detection versus range and azimuth from sensor performance prediction modules. This probability data is merged into a “probability of survival” matrix. A target probability density matrix is maintained and modified based on changes in the probability of survival matrix. The changing target probability density matrix is used to represent the effectiveness of the sonar search. The output provides the composite time dependence of the sonar search with the added advantage of not requiring constant monitoring. This paper addresses the sensor interfaces used, performance computations and the search effectiveness methodology