A novel method to improve the performance of Capon´s minimum variance estimator

An improved version of Capon´s (1969) minimum variance estimator (MVE) direction finding algorithm, titled “loaded Capon”, is proposed. In the new method, the diagonal elements of the covariance matrix are loaded with a fraction of the total power contained within the covariance matrix. A similar form of covariance loading has been proposed, by Carlson (1988), for adaptive beamforming when using sampled matrix inversion. Data from HF and VHF transmissions received with a multichannel direction finding system are used to verify the superior performance of the modified algorithm over the original MVE method. The performance of the loaded Capon is also compared with MUSIC, where it is found to have comparable performance, with the advantage of a greatly reduced computational burden