This paper proposes a displaced sensor array (DSA) configuration for estimating the angles of arrival of narrowband sources arriving at grazing incidence directions. Unlike the conventional uniform linear array (ULA) where all the array elements are aligned along one axis, the proposed DSA configuration comprises two displaced ULAs aligned on two parallel axes in the vertical plane. The steering vectors of the two parallel arrays differ from each other by only two multiplicative phase terms that represent the space factors due to the vertical separation and horizontal displacement of the two arrays. This makes the computational load of using MUSIC algorithm with the proposed DSA configuration identical to that of ULA yet the accuracy is much higher especially for cases involving narrowband sources arriving at grazing incidence angles. Simulation results obtained show that the proposed DSA configuration outperforms the conventional ULA in terms numerical accuracy and angular resolution.
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