Study on Ice Layer Thickness Inversion and Sound Velocity Measurement Techniques

The thickness of polar ice layers and acoustic velocity have significant applications in climate prediction, geological exploration, and polar engineering safety. Typically, in situ ice layers parameter measurements require drilling ice samples and measuring the speed of sound by directly measuring the thickness of the ice samples and utilizing the acoustic penetration method, which is highly inefficient for large-area observations. This paper proposes a method to invert ice thickness, Young's modulus, and Poisson's ratio using low-frequency guided wave dispersion curves, based on prior research and the actual characteristics of ice layer structures. Furthermore, by utilizing reflected waves from the bottom of the ice layers and applying an α-filter to extract the arrival times of primary reflected longitudinal and transverse wave signals, we calculate the acoustic velocity of the ice layers. The acoustic velocity shows minimal deviation compared to the inversion results. This study provides a theoretical foundation and methodological guidance for in situ measurements of polar ice layer parameters.