Discrete volumetric sonar method and apparatus for sub-seabed surveying

摘要

A method for imaging formations below the bottom of a body of water includes imparting acoustic energy into the formations along a predetermined length swath at a selected geodetic position. Acoustic energy reflected from the formations is detected along a line parallel to the length of the swath. The selected geodetic position is moved a selected distance transverse to the length of the swath. The imparting acoustic energy, detecting acoustic energy and moving the geodetic position are repeated until a selected distance transverse to the length of the swath is traversed. The detected acoustic energy from all the selected geodetic positions is coherently stacked. The detected acoustic energy is beam steered to each of a plurality of depths and positions along the length of the swath to generate an image for each such depth and position.

主权项

1. A sub-bottom sonar imaging apparatus, comprising:
a carriage assembly having mounted thereon at least one acoustic transmitter, at least one acoustic receiver mounted proximate the transmitter; a line array of acoustic receivers mounted on the carriage assembly in a direction transverse to a direction of motion of the carriage assembly; a position determining transponder mounted on the carriage assembly; a plurality of position determining transponders disposed at spaced apart positions and configured to communicate with the transponder mounted on the carriage assembly; at least two line arrays of acoustic receivers disposable substantially orthogonally on the bottom of a body of water; means for moving the carriage assembly to selected positions above the water bottom; and a signal detection and processing unit configured to coherently stack and beam steer signals detected by the line array of acoustic receivers mounted on the carriage assembly, the signal detection and processing unit configured to record signals detected by the line arrays of acoustic sensors deployable on the water bottom and signals detected by the at least one acoustic receiver mounted on the carriage assembly.