Array self-calibration with large initial errors

A self-calibration algorithm is presented for direction finding in the presence of unknown complex sensor gains. The method jointly estimates the directions of arrival of all the sources as well as the unknown gains. Existing self-calibration techniques are iterative and require sufficiently good initial estimates in order to converge to a correct solution. These techniques are ineffective in the presence of large calibration errors which make it difficult to reliably initialize the algorithm. The method presented here is non-iterative, does not require initialization, and is able to handle large sensor gain errors. The Cramer-Rao bound for the joint estimation problem is derived.