In eigenstructure methods for direction of arrival estimation of signal wavefronts, the additive noise term is assumed to be spatially white or known to within a multiplicative scaler. When the noise is nonwhite but has a known cross spectral, the problem can still be handled through pre-whitening. However, there are no techniques presently available to deal with completely unknown noise fields. In this paper, the localization of the wideband sources is studied when the noise cross-spectral matrix is an unknown banded matrix. The focusing operator developed in the literature, which is used to estimate the coherent signal subspace, is studied in the presence of spatially correlated noise. Some computer simulations are provided to illustrate the results.