Geoacoustic inversion of 3.5-kHz towed receiver data from the KOREX-17

Abstract

The Korea Reverberation Experiment 2017 (KOREX-17) was conducted in a shallow water located in the south of the Geoje island, Korea. During the experiment, sound propagation measurements were made using a 3.5-kHz CW signal along different 2 tracks to a distance of ~10 km from a bottom-mounted source, ARMS (Autonomous Reverberation Measurement System). The signals were received by a SRH (Self Recording Hydrophone), which was towed at a depth of ~20 m during the measurements. The sound speed profile was almost iso-velocity, and the sediment at the site was mainly composed of silt having a mean grain size of 6 phi. Since the sound propagation in shallow water is greatly influenced by sound interaction with the sediment, geoacoustic inversion was tried using a genetic algorithm based matched field processing in which the measured acoustic pressure field was compared to the simulated field predicted by a parabolic-equation based propagation model (RAM). The results are compared to the geoacoustic parameters obtained by the empirical relationship to mean grain size and a sediment layering information obtained by a chirp sonar survey. [Work supported by Agency for Defense Development, Korea (UD170014DD).]The Korea Reverberation Experiment 2017 (KOREX-17) was conducted in a shallow water located in the south of the Geoje island, Korea. During the experiment, sound propagation measurements were made using a 3.5-kHz CW signal along different 2 tracks to a distance of ~10 km from a bottom-mounted source, ARMS (Autonomous Reverberation Measurement System). The signals were received by a SRH (Self Recording Hydrophone), which was towed at a depth of ~20 m during the measurements. The sound speed profile was almost iso-velocity, and the sediment at the site was mainly composed of silt having a mean grain size of 6 phi. Since the sound propagation in shallow water is greatly influenced by sound interaction with the sediment, geoacoustic inversion was tried using a genetic algorithm based matched field processing in which the measured acoustic pressure field was compared to the simulated field predicted by a parabolic-equation based propagation model (RAM). The results are compared to the geoacoustic parameters ob...