Detection criteria and spatial-frequential smoothings

Three criteria used to detect how many uncorrelated excitations reach a passive array are examined in two cases: narrowband signals and wideband signals. Two of the criteria are the AIC-MDL (Akaike information-theoretic criterion/minimum description length) criteria and the third uses an adapted statistic of the logarithm of the generalized likelihood ratio. These criteria are compared using analytical simulations, and their performances in real situations are pointed out. The spatial smoothing procedure is also presented. It is shown that, by using both the diagonal elements of the spectral covariance matrix and the spectral smoothed covariance matrix, it is possible to compute the source correlation coefficients. Results on narrow- and wide-band source data recorded during an underwater acoustic experiment are presented