Estimation of the directionality pattern of a moving acoustic source

In many acoustic measurement situations the sound source is in motion relative to the observer. Source motion can have a considerable effect on the radiated sound field and the proximity of the source to a boundary can also significantly alter the sound field. This paper is concerned with the problem of estimation of the source directionality pattern from sound measurements which are both amplitude and frequency modulated in form due to the range, source directionality and the Doppler effect. The aspects addressed in the paper include (i) the modelling of the sound field; (ii) a description (analytical) of the methods of estimation of the directionality (which includes the Wigner-Ville and evolutionary spectral methods); and (iii) computational results showing the accuracy of estimation of a simple directionality pattern.