Effects of the fast perturbations on the performance of direction finder

The paper addresses the problem of predicting the DOA estimation performance of adaptive/optimum beamformer with fast in comparison with time adaptation of the algorithm sensor gain and phase perturbations. Modelling these errors as zero-mean Gaussian random variables that are identical but independent from element to element we derived the analytical expression for the loss of the resolving power of the two equal-energy uncorrelated sources. Analysis shows that it depends on the intensities of gain and phase errors and the power of the signals. Our resolution analysis is based on the assumption that the covariance matrix of the received signal will be determined exactly by averaging over an infinite period of time (the errors due to finite data are not included). To obtain more insight into effects of gain and phase errors, the analysis is simplified for two-source case assuming a uniform linear array with isotropic sensors of unity nominal gain