EM dual maximum likelihood estimation for wideband source location

Approximate maximum likelihood estimates and approximate dual maximum likelihood estimates for locating wideband sources in the presence of partly unknown noise fields are investigated. An extended model of the spectral density matrix of the sensor array output for coherent sources (multipath propagation) is introduced. The authors derive an expectation maximization (EM) iteration scheme for distributions belonging to the exponential family and investigate the so-called dual maximum likelihood estimate. The EM procedure is used to compute approximate maximum likelihood and approximate dual maximum likelihood estimates for source locations, signal, and noise spectral parameters.<>