The goal of this research program is to provide an "RF emitter map" of the battlefield by assembling properly synchronized direction-finding (DF) reports from multiple sensors. The proposed system applies a new technique that determines the location of an emitter with enhanced accuracy by optimally combining the data from multiple sensors in a synchronized network. The system will enhance conventional DF-based triangulation systems, which compute a line of bearing from each sensor as an intermediate step. The proposed technique utilizes a novel approach to processing multiple channels in parallel and has the added advantage that frequency-hopping emitters are less likely to go undetected. The location data would be viewed on a digital map display locally or over a wireless virtual private network. The proposed signal-combining approach is a logical extension of the approach developed by the proposing firm for geolocation of RF signals. Experiments with known waveforms have already successfully demonstrated improved location accuracy. In Phase I the system performance using airborne sensors will be studied through analysis and simulation. Performance improvements and system cost will be investigated and compared with other techniques of comparable complexity. A prototype design utilizing extensively commercial off-the-shelf components will be developed and outlined for Phase II with a plan for implementation. The primary application is the mapping of potential emitters in military operations. The proposed geolocation technique also has many law enforcement and emergency applications for locating radio transmitters, cellular handsets, or wireless PDAs. In addition, the technology can be used for locating special tags to find children, patients, and pets, as well as for tracking parolees, cargo, and vehicles.
