Disclosed are systems for determining the true angular position of a target with respect to a reference location. One such system employs a novel array of antenna units at the reference location. The units are uniquely excited by a pulse type signal in two opposite predetermined sequences to produce a pair of radiated pulse trains. A target located in the field of this array is illuminated by these radiated pulse trains each of which has a phase distribution proportional to the angular position of the target with respect to the array and opposite in sense to that of the other. Furthermore, the frequency of each pulse train undergoes a doppler shift due to the radial velocity, if any, of the target with respect to the array and therefore the ambiguity due to such shifts can be compensated for by detecting the phase distribution of each pulse train and processing the information obtained. In this manner an indication of the target''s true angular position, free from doppler ambiguities, can be provided either at the reference location alone, the target alone, or at both the reference location and the target.