NOAA researches autonomous survey system in the Arctic

By Rob Downs, Office of Coast Survey unmanned systems projects lead

A team composed of research engineers and a graduate student from the University of New Hampshire Center for Coastal and Ocean Mapping/Joint Hydrographic Center (UNH CCOM/JHC) and personnel from NOAA’s Office of Coast Survey are aboard the NOAA Ship Fairweather to test UNH’s BEN (Bathymetric Explorer and Navigator) unmanned surface vehicle (USV). On Saturday, July 28, the Fairweather made the first successful launch of a USV for an operational hydrographic survey from a NOAA vessel in the Arctic. The team conducted four additional deployments, including an extended overnight survey made in coordination with the ship.

The unmanned surface vehicle BEN launched from NOAA Ship Fairweather. Photo by Christina Belton, NOAA.
The unmanned surface vehicle BEN launched from NOAA Ship Fairweather. Photo by Christina Belton, NOAA.

Coast Survey will use the data BEN collects to contribute to Fairweather’s Point Hope survey project. With the support from the Fairweather’s command and crew, the team is operating USV hydrographic surveys in coordination with the ship and its survey launches to explore and develop new operational models with unmanned systems, identify and possibly solve shortcomings in the technology, and provide experience to the ship’s crew in the operations and support of unmanned systems.

The Arctic is well suited to testing unmanned systems because relatively low traffic minimizes the risk of encounters with other vessels. In addition, the expense of conducting hydrographic surveys in such remote areas makes the potential gains in the data acquisition capacity from USVs particularly attractive for NOAA survey ships.

BEN independently follows programmed lines.
BEN independently follows programmed lines.

BEN is manufactured by ASV Global and is significantly larger (13 feet vs. 3 feet), has a much longer endurance (more than 16 hours vs. 6 hours), and is faster (5 knots vs. 2 knots) than the small USVs operated from other NOAA hydrographic survey vessels. BEN is equipped with a standard suite of hydrographic survey equipment and can independently follow planned survey lines at a distance of approximately 5 miles from the ship. The USV can also be remotely driven when alongside the ship for deployment and recovery.

The capabilities of autonomous survey systems are rapidly advancing, and developing autonomous system technology and procedures is a key piece of Coast Survey’s autonomous systems strategy.

 

NOAA and Coast Guard survey shallow channels in eastern Chesapeake Bay to update aids to navigation

By Lt j.g. Patrick Debroisse

The area of the Chesapeake Bay along the Eastern Shore of Maryland is one of our nation’s treasures. Home to unique underwater grasses, fish, and shellfish, this complex transition from river to sea is also home to millions of tons of sediment delivered annually from eroding land and streams. Recreational boaters, fisherman, and cruising vessels are keenly aware of the shifting sands and sediment deposits in these shallow waters and rely on aids to navigation (ATON) — a system of beacons and buoys — to travel safely to and from the harbors and docks along the shoreline.

U.S. Coast Guard (USCG) Aids to Navigation Team (ANT) from Crisfield, Maryland, recently requested the assistance of NOAA’s Office of Coast Survey to help identify areas where ATON were in need of repair, relocation, or removal due to the shifting sediment of these nearshore areas. Crew from NOAA research vessel Bay Hydro II and from navigation response team (NRT) 1 (homeported in Stennis, Mississippi) operated an Echoboat autonomous surface vehicle (ASV) from a USCG vessel to survey these shallow waters. 

Lt j.g. Patrick Debroisse readies the Echoboat ASV for hydrographic survey
Lt j.g. Patrick Debroisse (NOAA, junior officer in charge, Bay Hydro II) readies the Echoboat ASV for hydrographic survey in the nearshore waters of the Chesapeake Bay.
Alex Ligon (NOAA NRT1) works with USCG Boatswain Mate (BM) 1 Lee Durfee, BM2 Collin Blugis, and Machinery Technician 3 Matt Kemp to load the ASV on the USCG vessel.
Alex Ligon (NOAA, NRT 1) works with USCG Boatswain Mate (BM) 1 Lee Durfee, BM 2 Collin Blugis, and Machinery Technician 3 Matt Kemp to load the ASV on the USCG vessel.

The team first visited Slaughter Creek, near Taylor’s Island, where the USCG believed sediment in the channel was shifting, requiring potential ATON relocation. The second area was in Pocomoke River, east of Smith Island, where shoaling in the already shallow channel was of concern, as well as the existence of unused ATON anchors. The ASV, equipped with side scan sonar to search for underwater objects, and a multibeam echo sounder to check the contours of the channels, surveyed both areas.

Once the survey data is processed and delivered to the USCG ANT, they can make informed decisions about ATON maintenance. Finding old ATON anchors and recycling them back into service is a potential cost savings for the USCG. NOAA and the USCG plan to operate the Echoboat ASV in this area again, surveying the waters for a possible wreck in Fishing Bay and for old ATON moorings replaced by a day shape.

Echoboat ASV surveys in the Pocomoke River Channel to investigate possible shoaling.
Echoboat ASV surveys in the Pocomoke River channel to investigate possible shoaling.
Alex Ligon (NOAA NRT 1) watches the ASV data in real-time. The ability to watch the data real time allows real-time decision making for survey planning and preliminary products to be provided to the Coast Guard ANT.
Alex Ligon (NOAA, NRT 1) watches the ASV data in real-time, which allows for real-time decision making for survey planning and preliminary products.

Coast Survey recently surveyed the waters of Lake Champlain using the Echoboat ASV.  This portable unit provides flexibility and allows survey teams to further develop procedures and to train more individuals in its use for future operations around the country.

NOAA surveys Lake Champlain for improved flood modeling and mitigation strategies

At the request of the NOAA Great Lakes Environmental Research Lab (GLERL), NOAA’s Office of Coast Survey deployed a survey team and a new autonomous surface vehicle (ASV) to gather hydrographic data in and around the narrow causeway inlets that dot the Lake Champlain basin in Vermont. GLERL will use the data to improve flood forecast models and analyze flood mitigation strategies in the Lake Champlain-Richelieu River system as part of a U.S. and Canada study led by the International Joint Commission.

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Navigation response team (NRT) members watch from the launch vessel as a new autonomous surface vehicle, the Echoboat, surveys shallow waters in Lake Champlain. The Coast Survey team included Mike Annis from headquarters and Alex Ligon and Josh Bergeron from NRT1 (Stennis, Mississippi) to support the ASV operations, as well as Lt. j.g. Dylan Kosten, Eli Smith, and Michael Bloom of NRT5 (New London, Connecticut) to provide additional support.

Lake Champlain drains northward to the St. Lawrence River (via the Richelieu River) and is part of the Great Lakes system. In 2011, the lake reached record water levels due to large amounts of spring precipitation, snowmelt, and runoff. This water caused more than 60 consecutive days of severe flooding that affected thousands of U.S. and Canadian residents.

To gather hydrographic data that will improve lake modeling and forecasting going forward, a Coast Survey navigation response team (NRT) deployed a Seafloor Systems Echoboat to survey areas of the basin that are too shallow for traditional survey vessels to reach. In this way, the ASV acted as a force multiplier to the NRT survey vessel. Coast Survey acquired the Echoboat earlier this year, and it is Coast Survey’s first ASV to be equipped with multibeam sonar—the same type of sonar that larger NOAA survey vessels use to gather high resolution hydrographic data. With the use of this technology, the data gathered by the ASV system may be included on NOAA navigational products.

 

Video: The new autonomous surface vehicle, the Echoboat, surveys shallow waters in Lake Champlain. 

 

This was the inaugural operational use of the Echoboat, and allowed the team to gain experience setting up, running, and maintaining the ASV. Identifying and addressing software and hardware issues now prepares the team for future deployments.

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Survey data of a causeway in Lake Champlain collected by the ASV (in the green polygon) and the NRT survey vessel.

Prior to the survey, much of the hydrographic data for Lake Champlain was well over 100 years old and of sparse density. Developers at GLERL needed more detailed hydrographic information in several shallow water areas in the northern sections of the lake to complete hydrodynamic models. Lake Champlain is a complex system populated with islands spread across multiple basins, many of which are connected by bridges and causeways. Critical to the flow of water between the different basins of the lake are multiple narrow, shallow inlets bisecting these causeways. The survey dataset Coast Survey delivered to GLERL is key to knowing the volume of water that flows through these bottlenecks in order to model circulation, water levels, and the resulting floods in the lake.