Sub-bottom profilers of the deep-sea research vessels
The sub-bottom profiler (SBP) installed on Ifremer deep-sea research vessels has been developed by Triton-Elics, in collaboration with Ifremer, Eramer and Enertest in 1998-1999. This SBP has first been integrated on the RV Le Suroît in 1999. Two other identical SBP have been integrated on the RV Pourquoi pas? during the ship building in 2004-2005 and on the RV Atalante in 2009. Today, the different parts of the acquisition chain are produced by IXSEA (acoustic array, electronics), Enertest (power amplifier) and HTDS (reception electronics). IXSEA sells this SBP, which is called ECHOES 3500.
On Ifremer vessels, data acquisition is performed with the acquisition system SUBOP, developed by Ifremer.
The acoustic array is integrated on the hull. It is made up of 7 Tonpilz transducers used for transmission and reception (the diameter of each transducer is about 30 cm). The array shape varies according to the vessel. Photographs of the SBP arrays of the RV Pourquoi pas? and L'Atalante are given below (left: array of the RV Le Suroît and Pourquoi pas?, right: array of the RV L'Atalante).
The frequency band of these SBP extends from 1.8 to 5.3 kHz. These SBP can be operated from shallow area (10 m) to deep-water area (about 4000 m). The penetration depth can reach about 100 m in soft sediments and the vertical resolution is lower than 30 cm.
SBP data example
The following SBP profile has been recorded on the RV L'Atalante during sea trials in the Bay of Bisquay in June 2009 (profile length ~9 km, vertical axis: two-way propagation time in ms, water depth ~4380 m).