Atmospheric sound transmission loss at the coast: A summary of observations

This work presents advances in an ongoing effort to amass a catalog of atmospheric acoustic transmission loss measurements that are made with coordinating high resolution meteorological observations in a near-shore environment. The measurement layout places the acoustic source at ranges from 250 to 2000 m from shore with a seven-channel vertical linear acoustic receiver array at the shoreline. Pure tone bursts are used with frequencies up to 2 kHz. The concurrent meteorological observations include high resolution temperature profiling, scanning Doppler LIDAR wind profiling measurements in the source-to-receiver direction, and water surface profiling. Observation generalizations are presented for cases of upward and downward refraction at different ranges, normalized to the prevailing wind direction. [Work supported by Office of Naval Research Awards N00014-22-1-2492 and N00014-24-1-2437.]