Tools for seafloor imaging

HOMESIDE (Deep-towed Multibeam Echo Sounder System)

HOMESIDE (Deep-towed Multibeam Echo Sounder System) Source: BGR

HOMESIDE (German abbr. for “HOchauflösendes Multibeam-Echolot, SIDEscan-Depressor”) is a deep-towed (down to 6000 m, towed 5 m to 250 m above the seafloor), high-resolution multibeam echo-sounder system, based on a Kongsberg model EM 2040 0.7° x 0.7° single RX echo sounder, which can be used for high/very high resolution (< 1 m) deep seafloor mapping. It is relatively small and easy to handle, even from smaller research vessels. The acquired data are transmitted ‘online’ through an electrical and single-mode optical fiber tow wire.
HOMESIDE is equipped with a Conductivity/Temperature/Depth (CTD) and sound velocity sensor as well as an inertial navigation system (INS), which is aided by a Doppler velocity log (DVL) and/or an ultra-short baseline (USBL) positioning system. Online SD/HD-video and obstacle avoidance sonar are possible options to allow operation a few meters above the seafloor for very high resolution mapping.

Video sledge STROMER

Source: BGR

The multi-functional video sledge STROMER (German abbr. for „Simpler TauchROboter, Multifunktional ERweiterbar“) is a remotely operated, deep-towed vehicle for deep seafloor exploration (down to 6000 m depth) using e.g. online SD/HD-videos, a remotely operated still camera with flash, sonar, and several sensors for the collection of physical and chemical parameter data of bottom waters. STROMER offers basic sampling capabilities using a 5-function manipulator arm, with which rock samples can be retrieved from the seafloor. STROMER is equipped with a propulsion system which allows movement within a limited radius (approx. 45 kg thrust). Water samples can be retrieved using small attached Niskin bottles

Side-scan Sonar

Source: BGR

The C3D sidescan sonar from the Teledyne Benthos Company is used to detect objects on the seafloor and for to map and classify the texture type of the seabed with a frequency of 100 kHz. The device is connected to the computer unit onboard the vessel via an electro-optical cable and is towed approximately 100 meters above the seafloor with a speed of 1 to 3 knots.