Matched field processing for a moving source
John M. Ozard, Gary H. Brooke, Scott Tinis · The Journal of the Acoustical Society of America · 1989
The detection or localization of a sound source in a multipath or multimode environment is improved by taking the multipaths into account through matched field processing (MFP). Frequency domain MFP (FDMFP) is very effective for a stationary source. However, there is an implicit averaging over time in FDMFP through the use of the Fourier transform and a further averaging if the covariance matrix is formed. Consequently, if the sound source is moving, the averaging of the time dependent signal will lead to an increase in ambiguity of the source position and a loss in array gain. When the source is moving, the received signal contains information about both source position and source motion. To take full advantage of the information in the time sequence, MFP in the time domain (TDMFP) was implemented. TDMFP is equivalent to obtaining the narrow-band gain and MFP gain in one step through the use of a Fourier transform modified by the propagation. Simulated results confirm the improved localization and array gain of TDMFP compared to FDMFP for a moving source.