Degradation of angular resolution for eigenvector-eigenvalue (EVEV) high-resolution processors with inadequate estimation of noise coherence

High-resolution, high-gain, and conventional processors were studied using simulation techniques. The sensors were in a uniformly-spaced linear array. The noise was either incoherent or isotropic. The high-resolution MUSIC processor was always configured as if the noise were incoherent. With incoherent noise present, the EVEV processor has extremely narrow angular resolution, much better than the other two processors. However, if the noise is not incoherent but really isotropic, there is an angular bias present with the high-resolution output when the signal arrives from near-endfire directions. The EVEV processor has negligible bias for most arrival angles with very favorable performance compared to conventional and optimal-gain processors.