Abstract:Research on marine observation equipment is crucial for marine infrastructure, particularly the environmental parameter measurement systems that effectively capture physical properties of shallow seas. This paper presents a method to characterize the relationship between dynamic medium parameters, acoustic excitation conditions, and acoustic field evolution based on the theory of acoustic scattering by shallow sea bubble groups. It details how the distribution of bubble groups relates to the medium′s acoustic parameters and leverages their unique scattering features to measure environmental parameters. The system employs narrow frequency-swept pulses to measure the incident sound pressure as well as the forward and backscattered sound pressure amplitudes of the target medium. From these measurements, the scattering and attenuation coefficients are obtained in real time and interpreted using bubble scattering and nonlinear parameter theories to derive shallow sea environmental parameters. Field tests conducted in a lake environment validate the measured scattering coefficients. Notably, while the nonlinear parameter of pure water is known to be about 3.5, measurements indicate values up to 90 in shallow seas, confirming that bubbles significantly increase medium nonlinearity and that pure water parameters cannot approximate shallow sea conditions. These results highlight the critical role of nonlinear parameter measurement. Compared with conventional systems, the proposed measurement system is simpler, highly adaptable to complex environments, and capable of rapidly measuring shallow sea environmental parameters. Importantly, it addresses the challenge of swiftly measuring nonlinear parameters in shallow sea settings, underscoring its practical significance.