Characterizing the impact of turbulence on an acoustic camera

This presentation investigates the impact of atmospheric turbulence on sound propagation using a beamforming array. Experimental measurements were conducted at the North Hartland Dam in Hartland, VT with a Nor848B acoustic camera and a dual-diaphragm compression driver serving as the sound source playing simultaneous frequencies at 225, 450, 900, 1800, and 3600 Hz. The source and acoustic camera were positioned approximately 100 m apart, with the source approximately elevated 55 m and the camera 1.5 m above ground level. A weather station, situated 2 m above the ground, was placed along the propagation path to monitor atmospheric conditions. Measurements were carried out at various times of the day to capture variability in different weather conditions. Observations using the acoustic camera revealed significant acoustic image wander and scintillation. This paper presents a statistical analysis of the acoustic image wander over time, and correlations between these variations and weather conditions.