Estimating directions of arrival with generalized MUSIC using a linear-interpolated array manifold

Interpolation problems involving the estimation of the directions of arrival (DOAs) of emitters using the generalized MUSIC direction finding (DF) technique are considered. In practical applications of DF, the spatial generalized MUSIC spectrum can only be computed exactly at a finite number of specified DOAs where the antenna array responses are calibrated. The methods of interpolating the spatial spectrum are developed to provide finer DOA estimates. The DOA estimates can be obtained via an iterative method involving generalized eigendecomposition to estimate multipath coefficients and quadratic programming to estimate DOAs. Conditions for the well-posed solutions and the convergence are discussed. Some numerical examples from both simulations and experimental data are presented to complement the mathematical results