Information content of reflection-coefficient data versus angle and frequency for geoacoustic inversion

Abstract

This paper considers the information content of seabed reflection-coefficientdata (as a function of angle and frequency) to resolve fine seabed structure through geoacoustic inversion. During the 2017 Seabed Characterization Experiment conducted on the New England Mud Patch, two types of measurement systems were employed to collect reflection data. One is a bistatic system with bottom-moored hydrophones and an omni-directional towed source, and the other is a towed system that uses the same source and a 15.4 m acoustic array on the same cable (source separation to the closest sensor is ∼ 27 m). Limited by the source–receiver geometry and data quality, the angular coverages of the reflection data for the bistatic and towed systems are ∼25–58° and ∼43–55°, respectively. This study aims to assess the capabilities of these systems to infer sediment structure using simulations over a frequency band of 1–6 kHz. Inversions show that the data simulated for the bistatic system better resolve fine structure of the seabed even with fewer frequency components, while the data for the towed system must include reflections at higher frequencies to get acceptable results. [Work supported by the Office of Naval Research.]