Direct position determination of narrowband radio transmitters

The most common methods for location of communications or radar transmitters are based on measuring a specified parameter such as signal angle-of-arrival or time-of-arrival. The measured parameters are then used to estimate the transmitter location. These methods are sub-optimal since they are indirect and involve two separate estimation steps. We propose a technique that uses exactly the same data as the common methods but the estimation of location is based on maximum-likelihood and the location determination is direct. Although there are many stray parameters, including the attenuation coefficients and the signal waveform, the method requires only a two-dimensional search. Monte-Carlo simulations indicate that the accuracy is superior to angle-of-arrival, time-of arrival and their combination.