The theory and analysis of the measured reflection coefficient
Reporter : Lin Chih-Wei
Abstract
The surface and bottom of the ocean are highly complex boundaries. They are usually rough, and underwater ground is an essentially inhomogeneous medium .The theory of reflection coefficient is completely applicable to the air-water interface and approximately to the water-ground boundary. The measured reflection coefficient can be used to identify the type of material (i.e. sand , clay , mud etc.) on the bottom . A swept FM , digital subbottom profiler , the chirp sonar , utilizes modern digital signal processing algorithms to generate high resolution images of ocean sediments . Matched-filter processing improves the inband SNR of subbottom returns by at least 20 dB . High SNR allows quantitative analyses such as reflectivity and acoustic attenuation measurements providing surficial and subbottom sediment classification .
Reference
•S.G. Schock, L.R. LeBlanc, Some applications of the chirp sonar, IEEE , OCEANS '90. 'Engineering in the Ocean Environment'. 69-75
• H.K. Ha , J.P.-Y. Maa , C.W. Holland, Acoustic density measurements of consolidating cohesive sediment beds by means of a non-intrusive “Micro-Chirp” acoustic system, Geo-Mar Lett , DOI 10.1007/s00367-010-0206-y