3D Acoustic Camera for Underwater Imaging

Underwater 3D Reconstruction for Underwater Construction Robot Based on 2D Multibeam Imaging Sonar

“…Moreover, the 3D data provided are not real-time because these need a certain amount of time to scan the surroundings. A 3D imaging sonar captures a 3D point cloud in real-time without any additional device (Hansen and Andersen, 1993;Hansen and Andersen, 1996). However, its relatively low resolution and high cost are the primary drawbacks.…”

A voting-based approach for fast object recognition in underwater acoustic images

“…Acoustic cameras that are able to form a 3D map of a scene and to project it on a plane thus to obtain a 2D image [1][2][3], have recently been put on the market. Among all the possible projections, the orthoscopic image (that is, the projection on a plane parallel to the array) is something of common interest for its similarity to the optical images.…”

“…Modern acoustic cameras, only recently commercially available, have a planar array of sensors and provide for real-time three-dimensional (3D) maps [1][2][3] of scenes that are some meters far from the array. These 3D maps are frequently displayed in a projective 2D version, like orthoscopic images or section images.…”

The application of real time 3D acoustical imaging

“…in a defined time slot, uses the two-dimensional extension of the back propagation algorithm described in [4] which is applied to a linear array of receiving hydrophones ' , 0-7803-5045-6/98/$10.00 0 1 998 IEEE Where b is the image vector containing the image points represented by their "real" and "imaginary" parts which just means that both phase and amplitude are generated. A' is the pseudoinverse of the acoustic propagation matrix A.…”

“…Since acoustic type sensors offer many advantages compared to video systems -such as the detection of -lots of efforts have been spent on the development of a 3D acoustic system capable of generating 3D acoustic images of the environment [ 1,2]. I Supported by a Norwegian oil company, Statoil, and the Norwegian Research foundation, OmniTech in Bergen has developed the first commercially available real time acoustical 3D camera -the Echoscope 1600 [3,4]. The development has targeted applications important to the offshore oil industry and to fisheries, but being a general type imaging sensors, the development will find its applications in a wide range of underwater activities like underwater construction work, research, environmental studies, seabottom surveys, survey of shipwrecks, dredging, military applications etc.…”