Experimental Localization of a Source of Thermal Acoustic Radiation by the Correlation Method

In the experiment, a source of thermal acoustic radiation was localized using the correlation technique, which employed a receiving array of four sensors for this purpose. A Teflon cylinder 5.5 mm in diameter cooled by 34°C relative to the environment was used as the source; it was located at a distance of 770 mm from the 20 mm sensors. Localization was performed at two positions of the source, the distance between which was 10 mm. The average reception frequency was 1.5 MHz. During localization, spatial correlation functions calculated for three pairs of adjacent sensors and for two pairs of sensors located “every other” were summed. The source images obtained in the experiment were spaced by 8.5 mm, the image size was 6 mm for the source in the center and 6.5 mm for the shifted source. Thus, the spatial resolution obtained with the given geometry corresponds to the calculated data for the sensor array and is significantly higher than the spatial resolution with non-correlation reception.