  In this paper, we present a novel auto-calibration scheme for the joint
estimation of the two-dimensional (2-D) direction-of-arrival (DOA) and the
mutual coupling matrix (MCM) for a signal measured using uniform circular
arrays. The method employs an integrated wideband dictionary to mitigate the
detrimental effects of the discretization of the continuous parameter space
over the considered azimuth and elevation angles. This leads to a reduction of
the computational complexity and obtaining of more accurate DOA estimates.
Given the more reliable DOA estimates, the method also allows for the
estimation of more accurate mutual coupling coefficients. The method utilizes
an integrated dictionary in order to iteratively refine the active parameter
space, thereby reducing the required computational complexity without reducing
the overall performance. The complexity is further reduced by employing only
the dominant subspace of the measured signal. Furthermore, the proposed method
does not require a constraint on the prior knowledge of the number of nonzero
coupling coefficients nor suffer from ambiguity problems. Moreover, a simple
formulation for 2-D non-numerical integration is presented. Simulation results
show the effectiveness of the proposed method.
