Direction of arrival estimation in the presence of correlated signals and array imperfections with uniform circular arrays

The Davies transformation is a method to transform the steering vector of a uniform circular array (UCA) to a vector with Vandermonde form. As this form is similar to that of the steering vector of a uniform linear array (ULA), we can apply to UCAs the many tools that have been developed for ULAs. However, the Davies transformation can be highly sensitive to perturbations of the underlying ideal array model. In this paper, we present a method for deriving a more robust transformation using novel optimization techniques. In particular, we consider its application to direction of arrival estimation in the presence of correlated signals. The effectiveness of the method is illustrated through a numerical example.