Design of a real-time multisensor search and track system

Low flying missiles present severe difficulties to shipboard radar systems, which must detect and track them in order to support defensive weapons systems. Propagation conditions at these altitudes create an impossible task for a radar only search and track system. To this end, the Naval Surface Warfare Center, Dahlgren Division (NSWCDD) has been investigating the use of a horizon search infrared (IR) sensor for assisting the radar in the target detection and tracking task. Ongoing scientific experiments have determined the characteristics of both the radar and IR sensor systems necessary to support this task. The definition of these sensors, along with knowledge of the propagation conditions have been drivers for the design of the algorithms and techniques for effectively integrating multisensor data. In the system described in this paper, active and passive sensor data is integrated to achieve improved firm track range. Detections from a horizon search infrared (IR) sensor and a horizon search radar are provided to a central sensor integration processor where both track initiation and radar dwell scheduling are performed. Significant increases in the detection range of the radar are achieved by using a high energy waveform along cued bearings generated by high confidence detections from the IR sensor. Previous results and recent real-time field test data are presented which support the system concept.