Fault Tolerance Analysis of Surveillance Sensor Systems

A surveillance sensor system is a network of sensors that provides surveillance coverage to designated geographical areas. If all sensors are working properly, a well-designed surveillance system can supposedly provide the desirable level of detection capability for the locations and regions it covers. In reality, sensors may fail, falling out-of-service. Motivated by the need to determine the ability of a surveillance sensor system to tolerate the failure of sensors, we propose a fault tolerance capability measure to quantify the robustness of surveillance systems. The proposed measure is a conditional probability, characterizing the likelihood that a surveillance system is still working in the presence of sensor failures. Case studies of the surveillance sensor system in a major US port demonstrate that this new measure differentiates different surveillance systems better than using the sensor redundancy measure, or the reliability measure.