抄録
A method to measure the acoustic holography by using a sub-array and a reference sensor has been used widely to reduce the cost of sensors and AD converters in the case that the sounds can be assumed to be stationary. However, it is difficult to find the best position of the reference sensor, since this method does not work well if the reference sensor picks up useless noise and reflections from the walls, floors or ceilings. Therefore, we propose a new method to measure acoustic holography by using a beamforming technique without the reference sensor. In the proposed method, the position of the original source which radiates the large sound power, is estimated by beamforming technique. By calculating the correlation function between the outputs of the beamforming, the, time lag due to the movement of the sub-array is compensated, and the compensated outputs of the beamforming are treated as a reference signal. It is found by computer simulations and an experiment that the estimation error due to the effect of other sound sources and reflections will reduce at most by about 10 dB by the proposed method using a sub-array with 15 sensors.
