Direction-of-arrival estimation in the presence of unknown nonuniform noise fields

A new method for estimating directions-of-arrival (DOA) of multiple spatial narrowband signals in the presence of spatially nonuniform independent sensor noise with unknown covariance is presented. An estimate of the colored noise-covariance matrix is given first. The received data for parameter estimation is then prewhitened using the estimated noise covariance, hence, overcoming the highly biased estimates. Furthermore, the performance improvement of standard MUSIC method is confirmed by computer simulations. © 2006 IEEE.