Direction-finding error model of two-dimensional phase interferometer under coherent interference

In order to evaluate the effect of coherent interference on direction-finding error in two-dimensional phase interferometer quantificationally, the expressions of sum signal which is added by source and interference signals were given based on the analyses of direction-finding principle of two-dimensional phase interferometer and formation mechanism of coherent interference. Here, the antenna array for receiving signals has two baselines and three elements. And then, the phase difference between sum signals received by each element was derived and the mathematical model of direction-finding error of two-dimensional phase interferometer with coherent interference was established. Finally, the experimental simulations were performed. The results show that in the two-dimensional phase interferometer direction-finding system, the direction-finding error is relevant to the direction of arrivals, the ratio of two amplitudes, and the phase difference of source signal and interference signal. In addition, the changing trend of this model is consistent with the principle of vector synthesis, so it is effective. Moreover, the direction-finding error decreases with the increase of elevation angles of the two signals, but it is unchanged with the change of azimuth angles. ©, 2015, Central South University of Technology. All right reserved.