Large systems which consist of many subsystems and work in conjunction with a variety of sensors are becoming evermore sophisticated. Modern aircraft and ships literally consist of hundred of systems and sensors. Effective methods for fusing data from sensors to obtain superior performance or achieve greater environmental awareness is vital issue. AIMS engineers are currently involved in a multi-year effort aimed at developing multi-sensor algorithms for tracking and surveillance. Work is underway on a sensor integration test-bed which simulates in software algorithms for sensor fusion in the context of naval ship systems.