Abstract: A system for tracking objects. Objects such as aircraft, ground vehicles, or vessels may be sensed with various sensors, including an Integrated Broadcast Service (IBS) (220), an Advanced Field Artillery Tactical Data System (AFATDS) (225), a network (230) of airborne radar sensors, a network (235) of aircraft each reporting its own position, a Blue Force Tracker (BFT) (240), and a network (245) of ground-based mobile radar sensors. Data from each sensor or network of sensors may also be fed, via a display interface layer (250), to a display. A tracker which may be referred to as a coherent aggregator (120) receives input from sensors or other trackers and also from an operator. The operator monitors the display and provides input to the coherent aggregator (120) to assist the coherent aggregator (120) in inferring tracks from measurement reports. Multiple coherent aggregators, in communication with each other and loosely coupled, may be operated simultaneously.