Three‐dimensional ultrasonic imaging of temperature distributions

Abstract

The investigation of the new opportunity of an acoustothermometer’s space resolution realization is described. The method is based on the correlation processing of signals received by the multi‐element piezotransducer. It is convenient to illustrate the method by the example of a reception of the signals irradiated by a point noise source by means of the two spaced transducers. The mutual correlation function of these signals has a maximum at the delay that is proportional to the path’s difference between the signal’s source and piezotransducers. Space resolution that is determined by the correlation maximum’s width is about a coherence length of the received signals. At the easily achieved frequency band of the received signals (∼1 MHz) it may be of a relatively small value (∼0.1 cm). The analytical solution of the problem of space distribution of noncoherent radiation’s sources by use of correlation processing of signals received by various elements of the transducers is presented. The opportunity of realization of a space resolution less than 1 cm at a distance of about 7 cm is shown by the computer simulation. It is essentially better using a known method based on the frequency’s analysis. Results of preliminary experiments are presented.