Bearing estimation with a linear array

This paper deals with the problem of bearing estimation of a monochromatic plane wave impinging on a linear array of M elements. Maximum likelihood (ML), amplitude monopulse and phase monopulse estimates are considered. Their accuracy are compared on the basis of a first-order expansion of their variance with respect to the inverse of the signal-to-noise ratio. Monopulse estimates have a smaller measure range, and unless signal bearing is near measure range middle, they cannot achieve a so good accuracy than ML estimate. Moreover accuracy depends on the squinted angle of both amplitude monopulse beams and on the distance between the phase centers of both phase monopulse beams.