1. A method of detecting a target in a room using a radar system having a transmitter for irradiating the object, a sensor for receiving reflected radiation, and circuitry for analyzing the reflected radiation to determine at least one characteristic thereof, the method comprising: determining at least one parameter for each wall of a plurality of walls of a room containing the target; determining possible signal paths between the target and the sensor for paths comprising up to N reflections based on the at least one parameter of the walls and the location of the sensor, comprising: determining a first set of possible signal paths from the target to the sensor; determining a second set of time-reversed possible signal paths from the sensor to the target; and determining the possible two-way signal paths based on a union of the first set and the second set; and calculating sensor image locations based on the possible signal paths; and processing the received radiation to determine a target location based on the sensor image locations.