Effective simplified decentralized target detection in multisensor systems

Decentralized target detection optimisation in multisensor systems, particularly in multisite radar systems, is usually reduced to the optimum choice of detection thresholds at all sensors and of a decision rule at the information fusion centre. For each decision rule, optimum peripheral thresholds are calculated by solving a system of m+1 complicated nonlinear equations in m+1 unknowns where m is the number of sensors. Since optimum thresholds depend on signal-to-noise ratios, those equations are to be solved practically in real time. Such a procedure is very cumbersome and requires large computational resources. In this paper, an alternative simple and effective approach to the problem is described. The key idea is a "uniform distribution" of any given output false alarm probability between all sensors. Thus solving the above mentioned equations and "tuning" local false alarm probabilities in real time are avoided. The performance analysis has shown that energy losses are small (with respect to the optimum procedure) for both fixed threshold and CFAR peripheral detection. Therefore, the suggested approach may be recommended for practical use.