An integrated acoustic and electromagnetic wave-based technique to estimate subbottom sediment properties in a freshwater environment

摘要

An integrated acoustic and electromagnetic (EM) wave-based technique was developed to estimate sediment porosity and top-layer thickness in shallow freshwater environments. The integrated methodology reduces the limitation of each of the individual techniques and combines the data for a more robust inversion solution. The acoustic and EM-wave reflection coefficients are determined based on the ratios of reflected signal strengths from sediments and a reference aluminium plate. An iterative algorithm that uses reflection coefficients to optimize the sediment porosity was developed. Once the optimal sediment porosity is obtained, the acoustic and EM wave speeds and then the top-layer thickness were evaluated. In comparison with ground truth data, the measured and estimated sediment porosity and top-layer thickness show differences less than 8.6%. The new integrated method provides an efficient and accurate methodology to obtain sediment properties under different sediment conditions.