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| Content Provider | IEEE Xplore Digital Library |
|---|---|
| Author | Jean, F. |
| Copyright Year | 2008 |
| Description | Author affiliation: Ixsea, La Ciotat (Jean, F.) |
| Abstract | SHADOWS is a new sonar system developed by IXSEA SAS. It is a towed fish composed of a synthetic aperture side-scan sonar and a forward-looking sonar. The system produces SAS images with a constant resolution 15 cm from 30 m to 300 m on each side. It also fills the nadir gap from 0 to 30 m with images having 40 cm times 15 cm resolution. The images are provided in real-time and are georeferenced. The synthetic aperture sonar Algorithm uses an accurate and highly synchronized INS combined with the Displaced Phase Center Algorithm (DPC) to calculate the high resolution images. The beam-forming algorithm used is the time-domain fast factorized back projection. This allows to compute a multithreaded algorithm and thus to lower the duration of the calculation. The forward-looking sonar uses a patented "sectorized emission" architecture. Four different signals are transmitted on four sectors of the gap illuminating the sea-bottom from 40 m to 100 m on the front of the fish. The images are side-scan-like, i.e. we see echoes and shadows as on the sides. We have a non-square resolution of 40 cm across track and 15 cm along track. The realtime algorithm can be customized to make some incoherent integration on several pings. A post processing algorithm can also provide an animation on a specific contact on the floor. An additional algorithm on the forward looking sonar signals can be used to increase the precision of the DPC navigation calculated on the sides. |
| Starting Page | 1 |
| Ending Page | 5 |
| File Size | 5685152 |
| Page Count | 5 |
| File Format | |
| ISBN | 9781424421251 |
| DOI | 10.1109/OCEANSKOBE.2008.4530934 |
| Language | English |
| Publisher | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Publisher Date | 2008-04-08 |
| Publisher Place | Japan |
| Access Restriction | Subscribed |
| Rights Holder | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Subject Keyword | Synthetic aperture sonar Transmitters Image resolution Bandwidth Signal resolution Marine animals Sonar navigation Transmitting antennas Frequency Time domain analysis |
| Content Type | Text |
| Resource Type | Article |
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