Geoacoustic inversion using very-low-frequency modal interference characteristics

Abstract

This paper presents a modal-based geoacoustic inversion method adapted for a very-low-frequency leaky waveguide. It is applied to air gun data collected by a seismic streamer during the multi-channel seismic exploration experiment in the South Yellow Sea. The inversion is carried out by filtering the waterborne and bottom-trapped mode pairs from the received signal and comparing the modal interference features (waveguide invariant) to replica fields. The effective seabed models are inferred at two positions, and the two-way-travel time of basement interface reflected waves calculated using these models exhibit good agreement with geological exploration results.