3D underwater imaging using vector acoustic sensors

Abstract

Marine surveys that use vector acoustic sensors may allow for 3D imaging of underwater environments with a much smaller amount of data than current 3D hydrophone surveys. Newly developed sensors make vector-acoustic-based surveys practical. This concept is demonstrated with data from a three-axis accelerometer and a collocated hydrophone in an acoustic water tank using a short-pulse source and passive scattering targets. One algorithm rectifies the vector data with scalar pressure data and another maps the vector data into a 3D volume, showing several slices of the volume images. The imaging algorithm maps the scattered energy using the direction and traveltime independently for each source-receiver pair rather than using the phase coherence methods common in exploration seismology. Imaging a more complex and realistic marine environment requires vector wavefield decomposition techniques and other theoretical developments but may allow for 3D vector-acoustic seismic surveys using logistics similar to 2D surveys that use conventional hydrophones.