Deep Sea Survey Equipment

 

GEOFORCE 4K DEEP-SEA DROP CAMERA SYSTEM 

Geoforce Group Limited introduces the ultimate digital stills drop/drift camera system optimized for cost-effective seafloor ground-truthing during deep-sea surveys.  Geoforce acquired a licence to commercialize the system from the Geological Survey of Canada – Atlantic (GSCA) at the Bedford Institute of Oceanography in Dartmouth, Nova Scotia.

 

FEATURES AND CAPABILITIES:

• Engineered for reliability and to achieve best data capture under challenging operating conditions, the camera system consists of high-quality commercial-off-the-shelf components that are packaged in sturdy pressure cases and a compact deployment frame.  

• The camera and dual flash units are powered by a high-capacity lead-acid battery, permitting continuous data collection for 12 hours and longer.  

• The image capture device is a Canon DSLR that can be exchanged with newer models as they become available.  

• A high-quality Canon wide-angle lens, a dome port for in-water correction and dual flashes for even illumination yield thousands of seafloor images on one battery charge.

• The versatile DSLR with exceptional sensor resolution, large range of light sensitivity and the lens’ optical properties form an outstanding workhorse tool for environmental baseline studies, geomorphological seafloor documentation and  much more.  

 
 

 

GEOFORCE DEEP-TOW HIGH RESOLUTION SUB-BOTTOM PROFILING SYSTEM

The evolution of the Geoforce DTS boomer/sparker sub-bottom profiler over more than four decades is an important case study in successful Canadian Government/Private Sector collaboration (McKeown et al, 2014). It demonstrates how a survey tool can retain its competitiveness in global seafloor mapping through continuous improvements building on a solid core technology. This presentation illustrates examples of sub-bottom profiles obtained with the TM Geoforce boomer/sparker, often under harsh conditions, building on the close collaboration between the originators Huntec ’70 Limited (Hutchins et al, 1976) and two government agencies at the Bedford Institute of Oceanography in Dartmouth, Nova Scotia. 

 

A COMPARISON: Geoforce DTS sparker data with airgun data

During the 2008 survey season off Labrador Canada, Natural Resources Canada collected data utilizing Geoforce DTS and Sercel GI Guns simultaneously. The figures below depict the resolution of the Geoforce/Huntec Data compared with the Sercel GI Guns used in conjunction with Teledyne 48 element 28420 Streamer

 

FEATURES AND CAPABILITIES:

• Tow speeds up to 10 knots maximum.
• Maximum DTS towing depth 500 metres.
• Results in water depths from 20 metres to 4500 metres.
• Penetration of up to 100 metres in soft sediments, 40 meters in sand when in boomer mode. 
• Penetration up to 80 metres in sand when in sparker mode.
• Layer resolution at the seafloor of 10 cm.
• Horizontal resolution equal to elevation of Tow Fish above bottom.
• Adjustable firing rates and source energy to meet a wide range of survey requirements and geological situations.
• Energy Storage Unit contained in Tow Fish, thus eliminating cable transmission losses.
• Boomer pulse shape and intensity independent of depth due to automatic depth compensation.
• Unique Body Motion Compensator allows operation in up to Beaufort Sea State 7-8.
• 540 joule/1000 joule sparker option allows greater survey flexibility.
• Can be run with one channel dedicated to resolution data, the other to penetration data.
 
 

TOP DOG DEEP SEA TOW SURVEY

The Geoforce DTS™ Deep Tow Survey boomer/sparker system is a high resolution sub-bottom profiler, incorporating boomer and sparker systems deployed in a single towfish. This system has been designed for use in the world’s toughest offshore environments, where reliability, ease of operation, and accuracy are of paramount importance.

Continuous improvements have led to the following features

• The Dynamic Depth and Body Motion Control System continuously monitors tow fish attitude and corrects the signal; data acquisition and visualization with Geo-Digs digitizer and proprietary software with programmable sampling on 3 channels plus trigger, up to 512 kHz.

• 24-hour operation; selectable energy source of 540 and 1000 Joules; typical tow speed of 4 knots to maximum of 8 knots; operation in water depth of 20m to 4500m. Thanks to the unique body motion compensator acquisition of quality data at up to Beaufort Sea State 7.

• Firing rate and source energy are adjustable to a wide range of survey and geological requirements.

BOOMER MODE

The heart of the DTS system is the patented depth-compensated 540/1000 Joule boomer sound source. In boomer mode, the Geoforce sub-bottom profiler drives a pressure equalized, electro-dynamic boomer plate as a directional seismic source that provides a highly repeatable impulsive signature over a frequency spectrum from 800 Hz to 10 kHz. Typical penetration is in the order of 100m in soft sediment and 40m in tertiary bedrock at high-resolution with discrimination of up to 10cm at the near sub surface. The boomer pulse shape and intensity are independent of tow fish deployment depth due to pressure compensation.

 

SPARKER FOR DEEP WATER

The sparker built into the Geoforce DTS™ produces high-resolution results in waters as deep as 4500 m.The Geoforce DTS™ boomer/sparker sub-bottom profiler offers great survey flexibility thanks to a number of factors, including operational capability in relatively high sea states, selection of source outputs and choice of boomer or sparker sources. In both options, the return is a heave-compensated, full-waveform signal with amplitude preservation.