Archive for the ‘Hydrographic surveys’ Category
How tall is that rock, really? Is that islet charted correctly? Mariners will have greater confidence in the location and height of charted features as NOAA’s hydrographic ships increase their use of newly adopted laser technology to measure and locate topographical features like rocks, islets, and small islands.
Recently, Lt. j.g. Patrick Debroisse, junior officer on NOAA Ship Fairweather, trained his NOAA Ship Rainier colleagues on how to use the topographic laser that they will soon be receiving.
“Fairweather used this laser throughout this past season for feature attribution, and I was tasked with creating the procedures and training other ships,” Debroisse reports. “Rainier will be the next ship to receive the lasers, followed by the East Coast ships [Thomas Jefferson and Ferdinand R. Hassler].”
NOAA charts features such as rocks, piles, islets, kelp beds, and buoys, to give the mariner a clear picture of the dangers that could be in the area. Along Alaska’s and Maine’s rocky shores, for instance, features can be especially important because the tide ranges can be large. It’s especially important to accurately measure a rock at low tide, so a mariner will know its depth when they can’t see it at high tide.
This area on chart 16604 illustrates features that could use the precision of topographic laser scanning.
Charted features are also used for visual points of reference during navigation.
Until recently, hydrographic ships’ launches were used to locate the features. To get a reasonable location, the launch would carefully approach the rock or other feature, and “kiss” it with their bow. They would then add the five feet from the boat’s GPS unit to the feature, and mark it on their field hydrographic sheets for use by the cartographers. If the seas are too heavy, or the area too rock-strewn, the surveyors stand on the ship or shore, and use a hand-held laser range finderto measure the height and distance of the feature, and then note the time so it can be corrected for the tide.
One of Rainier‘s four launches at work in Uganik Bay.
This laser technology will be safer than using a launch, and more precise than is possible with the human eye. The laser uses focused light to find and place objects accurately, similar to the way sonar is used to find the seafloor. The laser head produces sixteen laser beams, which reflect off the target object and are received back by the laser head. The computer then uses that data, along with precise positioning and attitude (roll, pitch, and yaw — or orientation) data, to determine the height and location of the object.
These infrared lasers are invisible and completely safe to the eyes of humans and any animals in the area. Also, unlike airborne lidar units that obtain shallow water bathymetry, the ships’ laser cannot penetrate the water.
“Fairweather worked with the Coast Survey Development Lab to test this laser scanner, to determine its feasibility as a topographical tool in the Alaskan environment,” Debroisse says. “We found that this laser method increased the speed and accuracy of data acquisition, and increased the safety of the boat crews completing these surveys.”
And safety, after all, is important for everyone from the NOAA charting teams to the millions of chart users.
History is never completely written. There are always new discoveries, new understanding.
NOAA historian John Cloud recently sent Coast Survey an intriguing report:
Yesterday I was looking for some historic Chesapeake Bay T sheets [topography drafts]… Anyway, down in the bottom of a folder, there was a zipped file, dated 2009, never unzipped. I thought: well, since I have noticed this now, why don’t I unzip it? It turned out to be two overly rescaled jpgs, but using my Keith Bridge tricks [a technique developed by a former Coast Survey historical chart expert] I found the two full-scale originals. It was one chart, with a small part cut off to make two separate files: the original 1838 hydrography for New Haven Harbour!
This is the basis for the 1838 engraved chart for Congress, the second published Coast Survey chart. (The first was based on Lt. Gedney’s partial survey of Newark Bay, NJ and the mouth of the Hackensack River, 1837.) The New Haven work was 1838. In 1839, the same Lt. Gedney and company captured the slave ship Amistad and brought the ship and captives to New Haven, claiming the escaped slaves as property. [UPDATE, 10/27/2016: Delving deeper into Gedney’s actions, it turns out he docked the ship in New London, while the captive Africans were brought to New Haven.] Then later, John Quincy Adams persuaded a judge they had freed themselves on the boat and were no longer slaves.
Unzipping the files happened within an hour or so of getting an email from Michelle Zacks, a scholar of marine environmental history who has explored historic Coast Survey field survey notebooks as sources for her ongoing project on the antebellum oyster industry and the lives of enslaved and free African Americans in the Chesapeake region. That research helped lead to her new job, as the associate director of the Gilder Lehrman Center for the Study of Slavery, Resistance, and Abolition, at Yale, which is in: New Haven!
It all happened just like that! Like the chart “wanted” to emerge back into the Amistad story.
We weren’t able to trace the origination of that zip file, but it was obviously created by someone who didn’t realize the value of the historical images. And this, ladies and gentlemen, is why we value historians.
By Ensign Michelle Levano
NOAA Ship Rainier recently arrived in Uganik Bay, off of northwest Kodiak Island, to complete hydrographic survey operations in Uganik Passage and Uganik Bay, including the Northeast Arm, North Arm, and South Arm. Rainier has spent 2013 through 2016 surveying areas around North Kodiak Island, including Kizhuyak Bay, Whale and Afognak Passes, Kupreanof Strait, and Viekoda and Terror Bays. The ship will remain in Uganik Bay until the end of October.
Rainier completed project areas H12916, H12919, and H12848 in the spring. They are now surveying H12693 south through H12849 and H12918.
Rainier is using multibeam sonar technology to acquire high-resolution seafloor mapping data to provide modern chart updates that support Kodiak’s large fishing fleet and higher volumes of passenger vessel traffic. Some of the data appearing on NOAA’s charts in this area are from surveys conducted between 1900 and 1939. (See the source diagram in the bottom left corner of NOAA chart 16597.) However, this is not Rainier’s first visit to Uganik Bay. In the early 1970s, Rainier was in the same vicinity performing survey operations and installing survey stations at Broken Point, Uganik Bay, and Shelikhof Strait.
Rainier crew at Broken Point, Uganik Bay, in the 1970s
Commissioned in 1968, NOAA Ship Rainier has a 48-year history in NOAA’s fleet of research ships and aircraft. Homeported at NOAA’s Marine Operations Center-Pacific in Newport, Oregon, she is operated and managed by NOAA’s Office of Marine and Aviation Operations. The 231-foot Rainier is one of four hydrographic survey ships in the NOAA fleet that support the nautical charting mission of NOAA’s Office of Coast Survey to keep mariners safe and maritime commerce flowing. The ship, her four aluminum survey launches, and other small boats collect data that is used to update nautical charts and inform decisions on coastal science and management.
NOAA Ship Rainier at anchor, in Uganik. Photo by Ensign Dylan Kosten
One of Rainier‘s four launches at work in Uganik Bay.
Each of Rainier’s small boat launches has modern sonar systems that gather data nearshore as well as offshore. Additionally, the ship itself has a sonar system mounted to her hull for offshore operations. This information can provide bottom seafloor habitat characterization for sustainable fisheries initiatives, and provide data for ocean tourism and recreational fishing.
If you happen to be in the area, and see a white hull with S-221 painted on her bow, please do not hesitate to contact the ship to acquire more information regarding the ship and her mission. Rainier monitors VHF channels 13 and 16. Or, email Rainier’s public affairs officer at firstname.lastname@example.org.
In a unique deployment of resources, last week NOAA Ship Fairweather split its scientific team and vessels to tackle two distinct projects in Alaska. Coast Survey physical scientist Katrina Wyllie and Lt.j.g. Bart Buesseler report on the multi-mission projects.
On August 9, NOAA Ship Fairweather departed Dutch Harbor, Alaska, for a FISHPAC project, led by Dr. Bob McConnaughey from NOAA’s Alaska Fisheries Science Center. This project’s primary mission is to statistically associate acoustic backscatter returns with the abundances of fish and crabs that frequent the Bering Sea seafloor. The science team accomplishes this with acoustic data from multibeam, single beam, and side scan sonars. Understanding the value of acoustic backscatter as a habitat-defining character will help scientists understand where fish live and the importance of different habitats. The acoustic data will also be used to correct for differences in the performance of research bottom trawls on different seafloor types, so that stock assessments and fishery management can be improved. To make sure the scientists understand what the acoustic data are showing, each day the ship will stop and collect physical bottom samples of the seafloor to see, touch, and interpret their findings. Further increasing the effectiveness of this mission, all of the multibeam bathymetry data acquired will directly support NOAA’s Office of Coast Survey as the data will be used to update soundings on the nautical charts for the eastern Bering Sea where the ship will be operating.
NOAA Ship Fairweather will survey the red tracklines for the FISHPAC project this year. The green lines will be surveyed at a later date.
FISHPAC mission equipment on deck of NOAA Ship Fairweather
With Fairweather actively conducting 24-hour ship survey operations in Bristol Bay, there wouldn’t be any chance to deploy her four survey launches for additional acquisition. Sensing an opportunity, the Office of Coast Survey, the command of the Fairweather, and Marine Operations Center-Pacific collaboratively came up with a multi-mission plan to maximize the capabilities of Fairweather during the FISHPAC project. Before departing Dutch Harbor, Fairweather deployed a shore team with the four survey launches to stay in Dutch Harbor and address some critical navigation needs identified by the port.
Two of the NOAA Ship Fairweather launches depart for a day of hydrographic surveying.
Although its location is remote, the port of Dutch Harbor is a vibrant and bustling port serving full-size container ships. It is the country’s top fishing port in terms of landings for the past 18 years. Deep draft and ice-free year-round, Dutch Harbor provides a critical link in America’s transportation infrastructure. Trivia buffs may also know that Dutch Harbor is the only other American soil, in addition to Pearl Harbor, to be bombed during World War II. (For more on Alaska in World War II, see USC&GS Ship Hydrographer contributes to significant Allied victory.)
With the increase in commerce flowing into and out of the harbor, local maritime pilots asked Coast Survey navigation manager Lt. Timothy Smith for updated nautical charts to improve the safety of maritime traffic. This need was underscored in July 2015, when a polar ice class vessel ran aground in an area of the chart which hadn’t been surveyed since before World War II. Shortly after this grounding, Fairweather was able to alter their schedule to conduct a response survey in the area of the grounding (green area in project sheet layout, below). Additionally, Fairweather had previously surveyed small high priority areas in 2011 (orange areas).
Project area of the north coast of Unalaska Island hydrographic survey project being conducted by NOAA Ship Fairweather launches.
This month’s collaborative project, performed in conjunction with FISHPAC, provided the perfect opportunity to address these navigational needs. With the survey launches remaining in Dutch Harbor, with a team of scientists, coxswains, and engineers to support them, Fairweather’s shore team will acquire complete coverage multibeam data in the entire project area, totaling approximately 38 square nautical miles, as outlined by the blue shapes in the project sheet layout.
The City of Unalaska has graciously facilitated this unique mission by providing pier space for all four launches for the project’s duration. The team itself has established a base of operations at the Grand Aleutian Hotel, where they have converted a conference room into a command center to process the day’s freshly collected data, while preparing the mission for the subsequent day.
The shore team has plenty of work to keep them busy until August 27, when Fairweather returns to Dutch Harbor after completing the more than 4,000 line-mile FISHPAC mission and recovers the survey team and launches. Fairweather then transits back to Kodiak, Alaska, for a scheduled inport and well deserved break before hydrographic survey operations resume in the vicinity of Sitkalidak Strait.
Lt.j.g. Bart Buesseler review multibeam bathymetry data in the shore team base of operations room.
Launch crews hold morning safety meeting at the pier.
The four launches tie up alongside at the Robert Storrs International Small Boat Harbor facility.
Additional resource:Combining expertise makes for better nautical charts and better understanding of fish habitats in Alaska, Oct. 9, 2012
From a NOAA National Ocean Service podcast…
Boaters rely on NOAA’s nautical charts for depth measurements so they don’t accidentally ground on sandbars or other underwater obstructions. See how NOAA updates nautical charts with high tech tools —including new experimental ocean “robots” that are small enough to survey the nation’s shallowest coastal areas.
Coastal planners, fishery managers, and oceanographic researchers will soon reap important seafloor and water column data from the coast of Washington, when NOAA Ship Rainier undertakes a special project in the waters within and near the Olympic Coast National Marine Sanctuary in May.
The blue lines indicate NOAA Ship Rainier’s survey project areas. From north to south, the project encompasses Juan De Fuca Canyon (65 square nautical miles), Quinault Canyon (378 square nautical miles), and Willapa Canyon (189 square nautical miles). The teal dots in Quinault and Willapa canyons are the locations of deep underwater natural methane gas seeps being investigated in a University of Washington research project. The green shaded area is the extent of the Olympic Coast National Marine Sanctuary.
The project, which is being managed by NOAA’s Integrated Ocean and Coast Mapping program, grew from NOAA’s National Centers for Coastal Ocean Science seafloor mapping prioritization exercise among coastal stakeholders from federal and state (Oregon and Washington) agencies, tribes, and academia. The group determined that one of the biggest needs by most of the organizations was a better understanding of canyon depths, seafloor, and habitat.
A scientific team of experts from the College of Charleston, University of Washington, and Oregon State University will contribute to the NOAA-led multi-disciplinary survey project, gathering data for a host of research projects and ocean management activities. In general, the data will collect swath bathymetry, acoustic backscatter, and water column data to:
- inform regulatory decisions on coastal development;
- provide benthic habitat mapping and seafloor characterization for sustainable fisheries initiatives, and to help assess fishery stocks and critical spawning aggregation locations;
- better understand and manage shelf and canyon resources;
- aid in resolving multiple-use conflicts;
- advance research in determining chemical and biological contamination levels; and
- provide a data repository for the development of ocean tourism and recreational fishing.
Some specific research projects are also planned.
- A University of Washington scientist will analyze the water column plumes over natural methane gas seeps in the planned survey areas. The university is a leader in the study of methane hydrates.
- Because Rainier heads to Alaska after the survey in the sanctuary, the ship will also conduct an exploratory survey to obtain seafloor imagery and data over a newly discovered mud volcano in the upper continental slope offshore of Dixon Entrance, just off the Inside Passage near Ketchikan, Alaska. California State researchers will use the data from this 40 square nautical mile survey to analyze the seafloor shape, assess the area for effects on potential tsunamis, and identify unique biological communities.
As part of her regular mission, Rainier will acquire depth measurements and other hydrographic data throughout the entire project to update NOAA nautical charts 18480 and 18500 off the coast of Washington, and chart 17400 in Alaskan waters. The corresponding electronic navigational charts (NOAA ENC®) are US3WA03M, US3AK40M, and US3AK40M.
Chris Stubbs, from the College of Charleston, will serve as the project’s chief scientist. Cmdr. Edward J. Van Den Ameele is Rainier’s commanding officer.
NOAA ship Rainier, a 48-year-old survey vessel, is part of the NOAA fleet of ships operated, managed and maintained by NOAA’s Office of Marine and Aviation Operations, which includes commissioned officers of the NOAA Corps, one of the seven uniformed services of the United States, and civilian wage mariners.