Localization of Land-Mobile Communication Transmitters

The objective of this project is to develop a software tool to localize transmitters at unknown locations broadcasting with unknown power based on the intercepted transmissions aggregated from a network of receivers over time. The only information available for the localization is the signal power at the locations of the receivers and the corresponding frequency bands used. The goal is to use such information to triangulate the locations of the transmitters. Many factors complicate the triangulation problem. First of all, for such land-based transmissions, attenuation of the signal strength depends on many environmental conditions and is often unpredictable. Furthermore, for higher frequency transmissions, small changes of the transmitter and receiver separation or even movement of nearby objects can also significantly change the strength of the received signal. In Phase 1, we focused on developing the propagation models of electromagnetic waves in realistic environments and the associated computational schemes to localize the transmitters. The localization results are displayed in the form of confidence maps, which can be overlapped on top of DTED maps to facilitate user decisions. This will lay the foundation for the Phase 2 development where the transmitters can be mobile and the locations of the transmitters are to be determined from the transmissions collected over an extended period of time.