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Marine Electronics


February 2013 Issue

Alfred Wegener Intitute Maps Arctic Seafloor in Permafrost
The Alfred Wegener Institute for Polar and Marine Research is using a Kongsberg Geoacoustics (Great Yarmouth, England) GeoSwath Plus Compact shallow-water multibeam system to map Arctic seafloor as part of the Coastal Permafrost Erosion Research Project (COPER).

COPER looks to describe and quantify Arctic coastal erosion, which is greatly sped during summer ice melt when less or no ice protects the coastline, and related carbon release by using air- and spaceborne methods together with field research.

Herschel Island, off the coast of Yukon Territory, Canada, in the Beaufort Sea, was selected for the long-term field study. In the 2012 field season, 3.1 square kilometers have been surveyed, mapping Pauline Cove with water depths of 1 to 17 meters in five days. This data set represents a baseline to which future surveys can be compared.

The remote location made it necessary to airlift all equipment and personnel. The survey was carried with an inflatable craft on which the splash-protected (IP54-rated) system was installed in a portable installation and powered by a 24-volt battery.

Falcon ROV Films Deep-Sea Species for Oceana
Conservation organization Oceana has explored undersea mountains in the Atlantic and Mediterranean using the Saab Seaeye Ltd. (Fareham, England) Falcon DR ROV. The 1,000-meter-rated ROV was used to record many species and habitats, including carnivorous sponges, lobsters and sharks.

The project began 240 kilometers off the Portuguese coast in the Gorringe Bank marine mountain range. Scientists filmed algae forests and hundreds of species, and noted the ecological value that seamounts offer to many species, including whales, dolphins and swordfish.

They have found species whose existence on the Gorringe Bank was previously unknown. When they later explored the Chella Bank, offshore Almería, Spain, they found protected species such as a carnivorous sponge and an angular rough shark at risk from damage to their seamount habitat by recreational and commercial fishing.

The high-definition cameras were manufactured and supplied by Marine Vision (Málaga, Spain), which also supplied the ROVs.

The Falcon DR came over from the Gulf of Mexico, where Oceana had used it to assess the long-term impact of the Deepwater Horizon oil spill.

Phoenix Recovers F-16 Aircraft
Phoenix International Holdings Inc. (Largo, Maryland) has successfully completed the underwater search and recovery of a U.S. Air Force F-16 aircraft from more than 16,400 feet of seawater (fsw).

Last summer, at the direction of the U.S. Naval Sea Systems Command’s Director of Ocean Engineering, Supervisor of Salvage and Diving (SUPSALV), Phoenix mobilized the Navy’s ORION deepwater side scan sonar system, the CURV 21 ROV, and the motion-compensated, 30,000-pound Fly-Away Deep Ocean Salvage System (FADOSS).

All equipment was transported over land from Phoenix’s facility in Largo to Dover Air Force Base in Delaware. From there, military transport aircraft moved the equipment to Hawaii, where the gear was loaded aboard USNS Navajo (T-ATF 169).

After a 10-day transit to the crash site, underwater search operations commenced using the Navy’s 20,000-fsw-depth search system, ORION. After searching the initial planned 2-by-4-nautical-mile area, search operations shifted to another high-probability area and the suspected F-16 debris field was identified.

Next, Phoenix personnel deployed the CURV 21 ROV and conducted a video survey of the area in which the flight data recorder and engine were identified. Over the next 10 days, the Phoenix team piloted the CURV 21 ROV through 12 dives and recovered all critical items desired by the embarked accident investigating board.

During operations, the team faced extreme water depths and adverse weather conditions, including erratic high winds, large waves and strong currents.

Remote Hydrographic Survey Boat Caught on Google Earth
Surveyors from Select Energy Services (Houston, Texas) were surprised to see one of their ROV’s hydrographic activities photographed and incorporated into Google Earth.

The team was preparing to do a hydrographic survey of a water holding pond for a natural gas fracturing operation using the Oceanscience (Oceanside, California) Z-Boat 1800 remote hydrographic survey boat. The Z-Boat incorporates a single-beam echosounder, GPS and telemetry system.

Prior to leaving for the survey site, the Select Energy Services process calls for the Google Earth map of the pit to be uploaded to the acquisition software to provide a background image for the survey plan and to offer clients a familiar perspective when viewing the final survey product. The Google Earth image showed a small yellow dot in the middle of the frac pit that seemed to have a wake behind it. When the image was zoomed in, the Z-Boat was clear in the satellite picture.

The photograph in Google Earth was taken exactly when the boat was at the pit during the previous time it was surveyed a few months earlier. Using a three-year average age for Google Earth imagery, the odds of this coincidence are about 1 in 25,000.

4.4-Terabyte-Per-Second Rate Achieved on Submarine Cables
TE SubCom (Morristown, New Jersey) has demonstrated 100 gigabyte-per-second-per-wavelength coherent transmission over transatlantic distances in field experiments, the company announced in January.

Capacity on a single fiber was determined to reach 4.4 terabytes per second with SubCom’s C100 transceiver, which is designed to optimize DP-QPSK coherent transmission in submarine cable systems with reaches up to 11,000 kilometers. The C100 technology applies to new systems based on +D fibers, as well as upgrades to existing systems with dispersion managed fiber.

The C100 transceiver has demonstrated capabilities of up to 15 terabytes per second on beta hardware prototypes.


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