Direction of Arrival Error for Localization Procedure of Sources with Directional Antenna

Most methods of radio emission source localization are based on an estimation of received signal parameters. Evaluation of signal reception direction is used in a method called a direction of arrival (DOA). The DOA is one of the most commonly used location methods in wireless systems. Its important advantage is independence from knowledge of a time-frequency structure of the received signal. Therefore, this method is used primarily in military radio reconnaissance systems and electronic warfare. In this paper, we evaluate errors in determining the DOA resulting from propagation phenomena occurring in an urbanized environment. A maximum power received from a given direction is the basis for the estimation of the DOA in most radio direction-finders. Thus, the direction of maximum radiation of the localized object is important because it causes a change of the extremum in a power azimuth spectrum (PAS). Simulation studies are the basis for assessing the DOA error for the transmitters with the directional antennas. To model the impact of propagation phenomena, a multi-elliptical model is used. This model considers the majority of propagation phenomena occurring in the urbanized environment. The possibility of considering patterns of the transmitting and receiving antenna is its important advantage. In this case, the Gaussian is used to model the pattern of the directional antennas. The assessment of the DOA error is carried out for non-line-of-sight conditions between the receiver and transmitter, i.e., the radio direction-finder and localized object, respectively. In simulation studies, the influence of the transmitting antenna parameters, i.e., its beamwidth and direction of maximum radiation, on a shape of the received PASs and their extremums is considered.