A novel RF emitter localization method through phase information

Localization of unknown radio frequency (RF) transmitters is useful for a variety of applications such as clutter cancelation, cognitive radio, cognitive radar, bistatic and multistatic radar. Current methods for localization include triangulation through phase difference, amplitude and time of arrival measurements. However, all these methods have their drawbacks. The received signal strength (RSS) based RF localization can have a degraded performance if a directional transmit antenna is employed or due to the effects of multipath on the received signal power. Time of arrival (TOA) and time difference of arrival (TDOA) based RF localization algorithms require the presence of features in the signal as a time reference. When such a feature is not captured by the receivers TOA and TDOA based algorithms produce ambiguous or imprecise results. In this paper, we propose a new method for RF localization which uses phase estimation and antenna patterns when traditional methods do not work well. Specifically, by exploiting the phase information captured at multiple receivers and the received antenna beam pattern, we can find the ellipses where the antenna beam patterns intersect and search the RF location within the intersect area. A Probabilistic Data Association (PDA) model is then employed to find a composite localization among all possible location candidates. Simulation results over multi-path environment confirms the effectiveness of the proposed scheme. A short treatment of moving transmitters is also provided.