Directional sources and beamforming.

Beamforming is done with an array of sensors to achieve a directional or spatially-specific response. It relies upon a model of the wave front (source model) arriving at the array to calculate the time delay, or frequency domain phase shift, that must be applied to the signal of each sensor so that they may be summed coherently. Beamforming may be used to improve signal to noise ratio, reduce reverberation, cancel interference, or estimate source location. In this talk the directionality of some real world sources that deviate from an ideal point source is discussed. Performance measures used to evaluate the directivity properties of a beamformer are reviewed. The validity of assuming a point source is examined and challenges for beamforming with non-point sources are discussed.