Open Access

Synthetic aperture technique applied to a multi-beam echo sounder

Earth, Planets and Space201453:BF03352388

https://doi.org/10.1186/BF03352388

Received: 1 July 1999

Accepted: 21 June 2000

Published: 18 June 2014

Abstract

We are developing a synthetic aperture technique using a Sea Beam 2000 multi-beam echo sounder to observe subsea crustal movements for earthquake studies. Augmented by the Kinematic GPS and a motion sensor, the synthetic aperture technique was successfully applied to the Sea Beam 2000 with a 12 kHz frequency acoustic signal. The 4.3-meter long projector produces a transmission fan beam in alongtrack beamwidth of 2 degrees, but a synthesis of the data achieved about 37 m aperture length, equivalent to a 0.3 degrees alongtrack beamwidth. Bathymetry measurements at the water depth of 900 m obtained through the synthetic aperture processing show considerable improvement of the signal-to-noise ratio and reveal detailed features of the seafloor.