A Method of Solving Ambiguity Based on Single Baseline Rotating Interferometer

The performance of most previous multi-channel two-dimensional direction of arrival (DOA) estimation array systems is pretty sensitive to various model imperfections, while the static single channel interferometer can only achieve one-dimensional direction estimation, thus the relationship between DOA estimation accuracy and the non-ambiguity scope needs to be weighed. In this paper, we propose a solving ambiguity method based on single baseline rotating interferometer. The baseline length is far greater than half of the target signal wavelength. The rotating interferometer rotates at the angular frequency, therefore the phase difference of a series of sampling points are able to measured. In addition, we deeply analyze the selection basis of sampling points pair and the source of angle measurement errors. In view of the limitation of the traditional algorithm on the maximum phase difference of adjacent pulses, an algorithm based on ambiguity numbers search (ANS) is introduced to obtain the correct ambiguity numbers and estimate the two-dimensional angle by using the cost function in the paper. The simulation results show that the proposed method is feasible and effective.