Wavefield boundary interactions in a multi-domain environment—Experimental results

Abstract

Acoustic and seismic signals may be generated and received in land, air, and water domains within a multi-domain environment such as a littoral (nearshore) zone. As the energy moves between domains, the waves undergo complex transformations at the media boundaries. Separate consideration of each physical domain (land, air, water) leads to an incomplete understanding of the full cross-domain wavefield, leading to significant challenges in interpreting signals and creation of accurate models that realistically couple multiple domains. To address this knowledge gap, a team at the US Army Engineer Research and Development Center constructed a simplified, uniform levee to enable the measurement of signals that had passed through undisturbed boundaries. Sensor types were medium-specific, with microphones in the air, hydrophones in the water, and accelerometers in the soil. Using electric bridge wire detonators (EBW’s), impulsive signals were generated in each medium type and measured on sensors in all three media. This presentation begins with an overview of the experimental design, discusses the medium-specific measurement results, and concludes with a discussion of joint multi-domain data analysis results. Approved for public release: distribution is unlimited.