후방산란 자료 활용을 위한 음압강도 추출기술 연구

Abstract

Since 40 years ago, multibeam echo-sounders (MBES) have been utilized as a method to accurately measure the depth of the seabed and has been collected vast amounts of data.

The MBES is an efficient and rapid remote sensing technique that allows for a comprehensive evaluation of the entire seafloor with minimal gaps.

The MBES system provides not only bathymetric information of the seafloor, but also offers acoustic characteristics, and qualitative and quantitative analysis methods of sediment deposition, making it an important tool for seafloor sediment analysis research.

The backscatter acoustic intensity obtained from the MBES is influenced by both the equipment characteristics of the employed system and the environmental factors of the marine environment, such as water temperature and salinity.

Typically, the post-processing of backscatter acoustic data involves commercial software provided by the manufacturers, which follows a standard procedure.

This study aims to quantitatively analyze the backscatter data obtained from the MBES by performing analyses specific to the characteristics of the different manufacturers' equipment, as well as removing compensation values applied to raw data, including TVG (time-varying gain), source level, beam pattern, and transmission loss, to extract the acoustic intensity.

For this purpose, a study area was selected, and data acquisition was conducted. The processed bathymetric data were utilized for the study. A self-implemented program in Python was used for calibration and intensity extraction, and during this process, the changes in acoustic intensity due to variations in the source level were correctly adjusted.

Additionally, the results obtained from sediment particle size analysis of surface deposits collected from the study area, combined with the results from this study, provided meaningful achievements in securing independent techniques for analyzing backscatter acoustic data.

In the future, for the standardization of backscatter acoustic data analysis, it is deemed necessary to conduct research and validation on compensating for transmission loss considering field marine environmental variables, compensating for incidence area based on seafloor slope, and correcting for angular response dependencies.

These efforts will be essential for further advancements in the analysis techniques of backscatter acoustic data.