1. A method for locating a transmitter, the method comprising: generating, at a receiver, a plurality of candidate locations for the transmitter based on signal ray characteristics of a plurality of signal rays, the candidate locations being points along an estimated path traversed by the plurality of signal rays from the transmitter to the receiver; calculating, for each candidate location, at least one weighted metric by summing a plurality of location metrics associated with each respective candidate location; locating the transmitter based on the at least one weighted metric associated with each candidate location; launching a simulated virtual ray toward a first point of incidence on the reverse path of a received signal ray, the first point being a last point traversed by a received signal ray, a point of incidence being a point at which a signal ray impinges with a structure or wall of a building; and simulating a reverse path of the received signal ray until a stopping condition is met; and calculating a predicted power for the simulated virtual ray at the first point of incidence, wherein the stopping condition is met if the predicted power is greater than or equal to a transmission power of the received signal ray, wherein a location metric for a first candidate location among the plurality of candidate locations is calculated, at least in part, based on a comparison between a prediction metric for a signal ray at the first candidate location and a prediction metric for the signal ray at a second of the plurality of candidate locations.