Optimized algorithm for solving phase interferometer ambiguity

Direction finding (DF) system using phase interferometer of long baselines gives high accuracy of angle of arrival (AOA), however, it also involves phase ambiguity and phase error. The paper presents a measurement of phase interferometer system, which was configured with three and four antenna elements, providing information of phase error. Moreover, a method including rotation of measured phase differences, labeling the phase lines and rounding value of phase difference was applied for determination of unambiguous AOA. The algorithm of AOA calculation was fast and optimized. The method was verified by experimental measurement combining with signal processing in MATLAB environment. The RMS error of phase measurement was 5.4° and RMS error of AOA determination was around 0.09°.