An algorithm of solving phase ambiguity of multi-baseline direction finding system based on sparse uniform circular array is proposed in this paper. This sparse uniform circular array whose inter-element spacing is larger than half-wavelength distance suffers from cyclic phase ambiguities, which may cause estimation errors. In order to solve the above phase ambiguities, the corresponding virtual short baselines are acquired by transforming the array element phases that meet with the contraction relationship. The obtained short baselines are used to solve the phase ambiguities according to the virtual baseline and stagger baseline theory. Highly accurate estimates of direction of arrival are herein acquired. Furthermore, the direction of arrival and polarization parameter estimates are automatically matched with no additional processing. The array arrangement problem in high frequency scenario is solved. The estimation accuracy of angle of arrival is improved by means of the phase ambiguity resolution. Simulation results verify the effectiveness of this algorithm.
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