Meg Stewart: Data Acquisition on a Small Boat: Tips and Tricks, July 14, 2019

NOAA Teacher at Sea

Meg Stewart

Aboard NOAA Ship Fairweather

July 8 – 19, 2019


Mission: Cape Newenham Hydrographic Survey

Geographic Area of Cruise: Bering Sea and Bristol Bay, Alaska

Date: July 14, 2019

Weather Data from the Bridge
Latitude: 58° 36.7 N
Longitude: 162° 02.5 W
Wind: 9 knots SE
Barometer: 1005.0 mb
Visibility: 10 nautical miles
Temperature: 61° F or 15.5° C
Weather: Overcast with fog, no precipitation

Fairweather in fog
The other day while on a survey launch, we came up on the Ship Fairweather as fog was rolling in.


Science and Technology Log

Launch preparation
A launch getting ready to survey. The setup process takes some time and all of the preparation is necessary for accuracy in the data.
Heave, pitch, roll, and yaw describe the movements of a boat (or a plane). An inertial measurement unit reads those discrete movements. Source: wikipedia

In the last post I talked about hydrographic surveying, the software used and the multibeam echosounder on the survey boats (called launches). The software is setup in the cabin by the hydrographer in charge. It takes a good five minutes to get an accurate read from the GPS (global positioning system) receiver. Then it takes time for the IMU (inertial measurement unit) to respond and start to read the boat’s heave, pitch, roll, yaw, and heading values. 

hydrograpers
The hydrographer in charge (standing) is showing the hydrographer in training (seated) how to setup the day’s survey project using the echosounder software.
launch data storage
The four Fairweather launches have the same, high-end technology in their cabins used to collect data from the multibeam echosounder, CTD sensor, a sound speed system, and a positioning and altitude system.

Often, the launch drives in a circle eight in order for the positioning receivers to be “seen” by the satellites, as a  stationary object is more difficult to detect than one that is moving. Setting up the day’s project using the multibeam echosounder software also takes some time but all the steps need to be done properly and to the correct specifications prior to starting the sounder. If not, the locational data will be wildly off and the depths inaccurate.

Another task that must be done from the launch before starting to transect is to test the salinity and water temperature using a CTD probe, which is called a cast. I mentioned this in a previous post. CTD stands for conductivity, temperature and depth. In the general area where the launch will survey, the CTD drops slowly to the bottom of the seafloor, collecting data that will be fed into the hydrographic program. Salinity and temperature at different depths will slightly change the rate at which sound travels in water. Again, the CTD process makes the location and depths as accurate as possible and must be done.

Meg casts CTD probe
Casting the CTD probe into the survey location to get conductivity, temperature and depth readings.

Usually, the chief hydrographer sets the defined area to be transected for the day and this is usually a polygon. The launch will sweep with the multibeam echosounder the outside lines and then scan at parallel set distances between the lines, either in a roughly north-south direction or a roughly east-west direction. For this particular hydrographic project, coverage of survey lines can be spaced at about 400 meters apart or greater apart depending on the depth. Recall that the nautical chart of Bristol Bay from the last post showed soundings dotting the area. Solid bathymetric coverage is not always needed on these projects. The Cape Newenham area has proven to have gradually varying depths and is mostly quite flat so free from obvious obstructions like large boulders and sunken ships. 

Once the technology setup is complete in the cabin, the hydrographer shares the map window with the coxswain (the person in charge of steering or navigating the boat). The hydrographer sets the points and the lines so that the coxswain knows where to direct the launch. And by direct, I mean the coxswain uses compass direction and boat speed to get from place to place for the survey. And the hydrographer in charge turns the echosounder on and off when the launch is in position or out of position.

Coxswain
The coxswain navigates the survey line set by the hydrographer in charge.

Because the transects run parallel to each other and are equally spaced apart, the hydrographers call this technique “mowing the lawn,” (see video below) for they are essentially mowing the surface of the ocean while the multibeam echosounder is collecting soundings of the surface of the seafloor.

A video of someone mowing a lawn on a riding lawnmower

A day out on a launch will go from about 8:30am to about 4:30pm but sometimes an hour or so later. If the Alaskan weather is cooperating, the hydrographers want to do as much as they can while out on the launch. Once surveying is complete for the day, the hydrographer in charge has to close up and save the project. Then data get transferred to the larger workstations and shared drive on the Fairweather.

Meg on launch
Every day on the launch, at least on this leg, has been great with perfect weather. And today, the added bonus for me was the phenomenal geology as we surveyed right along the shore.


Personal Log

I’ve taken loads of photos and video while at sea. I have tried to post just those pictures that help explain what I’ve been trying to say in the text. I haven’t posted any video on here as the internet on the ship is very weak. These next photos are a tour of different parts of the NOAA Ship Fairweather.

  • view of the bridge 1
  • view of the bridge 2
  • view of the bridge 3
  • barometer

The above slide show gives an idea of what the bridge is like. The ship is steered from the bridge. All the navigational instruments and weather devices, among other tools, are found on the bridge.

emergency billet
These emergency billets are for me, TAS Stewart, Meg, and it’s posted on my door. For each emergency situation, Fire, Abandon Ship, or Man Overboard, there is a bell sound and the location on the ship where I am to muster. Life at sea is all about being ready for anything.
mess
This is the mess (where we eat. And eat. And eat!) The food is fantastic but I’ve gained some pounds for sure.
Ice cream spot
Maybe this is why. Sometimes the Ice Cream Spot looks like this. Ha!
The galley
The galley
Laundry
Laundry machines available and detergent is supplied. No need to bring all your clothes. Also, sheets and towels are supplied.
Stairs
Stairs are called ladders on a ship. Makes sense to me – they’re often pretty steep. You must always hold a rail.
The Lounge
The Lounge
DVD collection
DVD collection of over 500 films
Lounge full of people
Yes, so this is the lounge and there can be meetings in here, training, movies, games, puzzles, quiet space, etc.
DVD in stateroom
Or, you can pop a DVD into a player in the Lounge, go back to your stateroom and watch. Or fall asleep. This is the original Blade Runner (which I never saw) and which I didn’t care for.
Finer things
The good folks of Ship Fairweather like to have a nice time every now and again, so they set up evenings, about once a leg, to have Finer Things. People come by, bring fine cheeses, fine chocolates, fine almonds, fine fig jelly, and fine maple sugar candy from Rhinebeck, NY, and have a fine time. And a disco ball.


Did You Know?

Inertial Measurement Units (IMU) technology that is so important for accurate hydrographic survey mapping was developed by the U.S. military. IMUs were used in the development of guided missiles, unmanned aerial vehicles (and now drones), battlefield reconnaissance, and target practice.

Quote of the Day

“A ship in port is safe, but that’s not what ships are built for.” – Grace Hopper

Lona Hall: Meeting, Greeting, and Settling In, June 3, 2019

NOAA Teacher at Sea

Lona Hall

Aboard NOAA Ship Rainier

June 3 – 14, 2019

 

Mission: Kodiak Island Hydrographic Survey

Geographic Area of Cruise: Kodiak Island, Alaska

Date: June 3, 2019

Local Time: 1100 hours

Location: Alongside, JAG Shipyard, Seward, AK

Weather from the Bridge:

Latitude: 60°05.1022’ N
Longitude: 149°21.2954’ W
Wind Speed: 5 knots
Wind Direction: E/SE (114 degrees)
Air Temperature: 12.12° Celsius

Lona Hall on NOAA Ship Rainier

Enjoying the fresh air

Science and Technology Log

While at port in Seward, it has already been my pleasure to meet some of the people that make up the team of NOAA Ship Rainier.  My mission so far has been to learn about the different capacities in which individuals serve on board the ship and how each person’s distinct responsibilities combine together to create a single, well-oiled machine.  

The five main departments represented are the NOAA Commissioned Officers Corps, the Hydrographic Survey Technician team, the Engineering team, the Deck department, and the Stewards.  There are also a few visitors (like me) who are here to observe, ask questions, and participate in daily operations, as possible.

Career Focus – Hydrographic Survey Technician

Today I spent some time with Survey Technician, Amanda Finn.  Amanda is one of nine Survey Techs aboard NOAA Ship Rainier.

Amanda Finn, Hydrographic Survey Technician

Amanda Finn, Hydrographic Survey Technician

What is hydrography?

According to the NOAA website, hydrography is the “science that measures and describes the physical features of the navigable portion of the Earth’s surface and adjoining coastal areas.” Essentially, hydrographers create and improve maps of the ocean floor, both deep at sea and along the shoreline.  The maps, or charts, allow for safer navigation and travel at sea and are therefore very important.

(Click here to see the chart for Resurrection Bay, where the ship is currently docked.)

 

What does a Hydrographic Survey Technician do?

Technicians like Amanda are in charge of preparing systems for collecting hydrographic data, actually collecting and processing the data, monitoring it for quality, and then writing reports about their findings.  They work part of the time on the ship as well as on the smaller launch boats.

 

What kind of data do Survey Techs use?

Both the main ship and the small launches are equipped with multibeam sonar systems.  SONAR is an acronym for Sound Navigation and Ranging. This fascinating technology uses sound waves to “see” whatever exists below the water.  Instead of sending out one sound wave at a time, the multibeam sonar sends out a fan-shaped collection, or swath, of sound waves below and to the sides of the boat’s hull. When the sound waves hit something solid, like a rock, a sunken ship, or simply the sea floor, they bounce back.  The speed and strength at which the sound waves return tell the technicians the depth and hardness of what lies beneath the ocean surface at a given location.

small vessel in the water

Small launch for near shore survey

Personal Log

It is possible to be overwhelmed in a good way.  That has been my experience so far traveling from my home in Georgia to Alaska.  The ship is currently docked at the Seward shipyard in Resurrection Bay. When you hear the word “shipyard”, you might not expect much in the way of scenery, but in this case you would be absolutely wrong!  All around us we can see the bright white peaks of the Kenai Mountains. Yesterday I stood in one place for a while watching a sea otter to my left and a bald eagle to my right. Local fishermen were not as enchanted as I was, but rather were focused on the task at hand: pulling in their bounties of enormous fish!

View near Seward shipyard

Out for a walk near the shipyard

I am similarly impressed with the order and organization aboard the ship. With over fifty people who need to sleep, eat, and get things done each and every day, it might seem like an impossible task to organize it all.  By regular coordination between the departments, as well as the oversight and planning of the ship’s Commanding Officer and Executive Officer, everything flows smoothly.

I think that it is worth noting here how the level of organization that it takes to run a ship like NOAA Ship Rainier should not be taken for granted.  Every individual must do their part in order to ensure the productivity, efficiency, and safety of everyone else.  As a teacher, we often discuss how teamwork is one of life’s most important skills. What a terrific real-world example this has turned out to be!

NOAA Ship Rainier

NOAA Ship Rainier

Did you know?

Seward is located on the Kenai Peninsula in southern Alaska.  The name Kenai (key-nye) comes from the English word (Kenaitze) for the Kahtnuht’ana Dena’ina tribe.  The name of this tribe translates to “people along the Kahtnu river.” Click here for more information about the Kenaitze Indian Tribe.

Word of the Day

fathom: a unit of length equal to 6 feet, commonly used to measure the depth of water

Brandy Hill: Chat with Chief Engineer and My First Tuna Catch, June 28, 2018

 

NOAA Teacher at Sea

Brandy Hill

Aboard NOAA ship Thomas Jefferson

June 25, 2018 – July 6, 2018

 

Mission: Hydrographic Survey- Approaches to Houston

Geographic Area of Cruise: Gulf of Mexico

Date: June 28, 2018

 

Weather Data from the Bridge

Latitude: 28° 50.7’ N

Longitude: 093° 34.4’ W

Visibility: 10+ nm

Sky Condition: 4/8

Wind: 12 kts

Temperature:

Sea Water: 29.6° C

Air: 29.3° C

 

 

Science and Technology Log

This afternoon I spent an hour with Chief Marine Engineer, Thom Cleary. As promised, he gave me a tour of the Engine Room. Thom arrived on the Thomas Jefferson in 2011 and has worked not only on maintaining operations, but greatly improving them. When asked about his favorite ship mechanism, he responded with one that is not his favorite but of which he is most proud. The Thomas Jefferson, along with most other ships, typically used to rid greywater and sewage by offloading into the ocean. The EPA states that ships must be at least one nautical mile from land or people in the water and three nautical miles from aquaculture (2018). With hydrographic survey operations taking place in “no discharge” areas (close to shore), this could complicate and/or slow down the Thomas Jefferson’s progress.

Realizing the inefficiency and in an effort to improve, Thom investigated other options. It was decided that a fuel storage tank would be converted to hold more wastewater. After a long wait period, the new method was installed. Within the first season 38,000 gallons of sewage was stored and discharged to a shore treatment facility. Today, the tanks have gone almost two months without release into the Gulf of Mexico. This improvement has allowed hydrographic operations to continue without interruption, conserves fuel, and increases efficiency.

Renovations to the Thomas Jefferson did not stop there. Originally constructed in 1991, the ship has room for many other improvements. Thom and team advocated for all natural lubricants (rather than petroleum), switched all light fixtures to LEDs, and adjusted the ballast system. In 2016 the roughly 122,000 gallon ballast system changed from using sea to municipal water. This now allows the ship to move from multiple coastal waters without concern for carrying invasive species in the ballast tanks. In addition, the new waste water tank was strategically placed in the center of the ship to help with stability.

Ballast diagram

Ballast diagram showing invasive species risk. (CC)

Thom is an innovator and self-described incorrigible tinkerer. Many of these changes would not have been made without his (and team’s) desire and advocacy to make things better. When I asked if these upgrades were standard on ships, he mentioned that the Thomas Jefferson is a trailblazer.

Chief Engineer Thom Cleary

Chief Engineer Thom Cleary and the desalination/ reverse osmosis system. The RO typically operates at 650 psi (with 900psi maximum potential) and pushes sea water through a membrane creating potable water for the ship.

 

Personal Log

CO (Commanding Officer) authorized a launch on one of the boats. After some mishaps with a fuse, the crew performed multiple safety checks and we were cleared to go. Mission: collect survey data near a stationary platform. CO’s comfort level to obstructions with the main ship is a half-mile, so having the smaller launch boats is helpful when surveying areas like this.

Launch Boat Approach

The launch boat crew from left to right: Lt. Klemm, Kevin Brown, Pat Osborn, and Brandy Hill (below deck).

 

SurveyNearPlatform

Survey area near the stationary platform. The ship to the left is a supply vessel.

While cruising out to the survey area, I spoke with Pat Osborn, part of the Thomas Jefferson’s deck crew and our survey line driver for the day. Pat has two years of training and was explaining that he is still learning parts of his job. (Everyone on the ship wears multiple hats.) He spoke highly of his job and appreciated the multi-dimensional relationship between CO and the crew. Pat explained that CO is not expected to be an expert in all areas of the ship- there are safety checks (such as preparing for the launch) where the CO asks lead crew members to evaluate and sign-off prior to action. Every mission I’ve observed and attended has proceeded in this manner. It is a highly respectful and safe environment.

AllisonLaunchApproach

Chief Survey Technician, Allison Stone, awaiting launch boat arrival.

Launch Return to Ship

Patrick Osborn approaching ship Thomas Jefferson with the launch boat.

KevinDeployingCTD

Kevin Brown lowers the CTD while the boat is stationary. A CTD captures the salinity, temperature, depth, and concentration of particles in the water column. This information is used for analyzing the survey data. On the ship, this information is collected using an MVP which allows the ship to stay in motion.

As soon as we had the survey equipment set up and running, survey technician Kevin Brown brought out a fishing pole. I hadn’t realized that we could fish while out on the boat! We proceeded to catch and release about 10 tuna (likely False Albacore and Bonito). Kevin reeled in two, then passed the pole to me. I couldn’t believe how hard it was to real in a fish. I was reading that they can stay on the line and swim up to 40 mph!

Brandy reeling

Brandy Hill’s active line power stance.

False Albacore

Brandy Hill and her first fishing boat catch, False Albacore.

Peaks

 + Witnessed hard work and precision paying off- the launch boat survey data had an error of 0.0006 meters. The data is highly accurate!

+ Drove “the survey line” on the launch boat. (More of an explanation coming soon.)

+ Reeled in a beautiful, tough fish.

Note: After the seasickness subsided, I’ve decided to leave out the “Valleys” category. I’m having a great time.

Lisa Battig: Nome, Alaska & Launch 2808, August 30, 2017

NOAA Teacher at Sea

Lisa Battig

Aboard NOAA Ship Fairweather

August 28 – September 8, 2017

 

Mission: Hydrographic Survey leg IV

Geographic Area of Cruise: Alaska

Date: Wednesday, August 30, 2017
Location: Port Clarence: 65o14.034N 166o43.072W

Weather on the bridge:
30+ knot winds, 42o F, 4ft seas, heavy stratocumulus clouds (9/10 coverage)

Science & Technology Log

Over the past two days I have been introduced to tremendous amounts of the science of hydrography. In this blog post I will focus on the hardware used and the process of surveying. There are two types of sonar that are being employed. The first is side scan sonar and the second is multibeam sonar.

Side Scan

Side scan array sonar housed underneath one of the small launch vessels

 

Side scan is shorter range and performs better in shallower water. Side scan is used in conjunction with multibeam, however, as side scan does not give true depth values. The function of side scan is to show features evident on the ocean floor. For this reason, multibeam is run in conjunction with side scan in order to keep an accurate record of depths.

Multibeam

Multibeam sonar housed underneath another of the small launch vessels

Multibeam shows an exact depth. Due to the fact that it is an angular spreading band from the center of the underside of the launch, at shallow depths it will only show a very narrow strip of ocean floor.


Stop and imagine…a lit flashlight shining on a wall from only a few centimeters away. What happens to the image on the wall as you pull the flashlight back? The area of coverage of the image will become larger. The concept is similar for the multibeam in shallow versus deeper water.


Using multibeam in shallow water then would create a need for more passes closer together in order to cover an area. There are instances where using this technology even in shallow water would make sense, but for a full coverage survey, this would not be the case.

CTD Image 2

A CTD; it contains sensors for conductivity, temperature and density of the water column

The third piece of hardware used for the standard small boat launch hydrographic surveys is the CTD device. The CTD will measure conductivity of the water and also give both a temperature and density profile. The CTD is deployed multiple times during a survey as a tool to calibrate the data that is coming in via the sonar. Conductivity of the water gives an estimate of the total dissolved solids in the water. This information, along with the temperature and density will give an estimate of sound speed through the water column.


Stop and try this one for better understanding… knock on a door normally with your head roughly arm’s distance from the point where you are knocking. Now repeat the process of knocking, but with your ear pressed against the door approximately an arm’s length away from the knock. What is different? You should have noticed that a more precise (and typically louder) sound reached your ear. If you pay close attention, you will also notice that the sound reaches your ear more quickly. This is roughly analogous to how changes in the water column will affect sound speed.


The final piece of equipment used regularly for surveys is a HorCon (horizontal control) station. This is a land-based station that will help to define accurate position in the water. It allows for greater precision with global positioning data. The signals of satellites responsible for global position are affected daily by changing atmospheric conditions. Moreover, the precise positions of the satellites themselves are actually not well known in advance. This may result in a GPS location moving a few centimeters in one direction or another. While this is not going to heavily impact your ability to find a Starbucks in a strip mall, it can have a definite impact on the accuracy of charts for navigation. The HorCon station always remains in the same place on land, and can therefore be used to calibrate the measurements being read in the survey waters nearby and that information can be used along with corrected satellite positions since it is coming after the fact.

Port Clarence chart

A nautical chart of the Port Clarence and Grantley Harbor area where we were surveying

Today we worked in Port Clarence, Alaska, both outside and inside of Grantley Harbor. Most of the depths being surveyed are in the 4-6 meter range. The particular area being surveyed had been previously surveyed in the 1950s by the US Coast and Geodetic Survey, likely using a single beam sonar system. The current survey is intended to note changes that have occurred since that prior survey and to accurately update all of the charts. The area of western Alaska is expected to increase in boat traffic over the coming years due to the opening of the Northwest Passage from the Pacific to the Atlantic via the Arctic. This route is significantly shorter for most shipping traffic than the route through the Panama Canal. Because of this expected increase in traffic, there is a need to identify areas for sheltering during heavy seas. Port Clarence is a natural inlet that offers some protection and holds potential for this purpose.

The process of surveying:
Two launches were deployed. I was on launch 2808, the second described here. The first was equipped with only multibeam sonar and the second had both multibeam and side scan. The plans for the two launches were different. The launch with only multibeam was working in an area of Grantley Harbor and covering an area that had previously been mapped to insure that the values were acceptably accurate. This focus existed primarily because of extra time available up in this area. The launch running the side scan was completing some unfinished work in Port Clarence and then did further work inside of Grantley Harbor. These areas, or “sheets” are described below. As a side note, small boat deployment is a fascinating and involved activity that I will discuss in a later blog.

Survey areas are broken up into sections known as “sheets” – each sheet has a manager. This person will be from either the NOAA Corps or a civilian member of the scientific survey team. The sheet manager will be responsible for setting up the plan for survey and doing all of the final checks after data has been gathered, cleaned and examined to determine if there are areas that should be rechecked or run again before it is completed and undergoes final processing.

A sheet manager will need to consider several questions prior to setting up the initial parameters for the survey. What is the depth being surveyed? What type of bottom is it? What type of coverage is needed? All of these factors will come into play when determining how the lines will be run – how long, how far apart, which sonar type, etc.
Once the plan is determined, it will be the job of the Operations Officer, LT Damian Manda, to parse out the duties and create a daily work plan to cover all of the areas. Each day, multiple launches will be sent out to gather data as described above. As the fieldwork finishes for the day, data will be transferred to a drive and then brought into the ship’s mapping room where night processers will begin the lengthy work of checking and cleaning the data so that it can all be ready for the final processing step prior to being sent to the client.

HMarshburn at computer

Senior surveyor Hannah Marshburn at the computer terminal in launch 2808

How good are those data?
There are several checks built into the data collection process. First, the survey team members on the launches are watching in real time. With three screens to work from, they are able to see what the sonars are seeing and can also set certain limits for the data that will alarm when something appears to be contrary to what’s expected. Night processors look for anomalies in the data like sudden inexplicable drops in depth in an otherwise flat surface or an extremely “noisy” area with little good data. Any area with a former survey will also be compared to the previous values with large differences signaling possible issues. Many trained eyes look at the data before it is accepted for charting and there will commonly be at least one return to an area to check and recheck prior to completion. One area in the current survey has continued to show odd results, so trained NOAA divers will dive the area to find out what is really going on.

Personal Log

So far this has been an amazing experience. I fully enjoy being among the crew of the Fairweather and living on the ship. It’s hard to say what my favorite part has been so far because I have honestly enjoyed all of it! Since we didn’t get underway until Monday, I had the opportunity on Sunday to roam around Nome with a couple of the other folks that are just here for two weeks, LT Joe Phillips and LCDR Ryan Toliver. I learned a lot more about both the NOAA Corps and the Public Health Service of which they are respectively a part. (These are two of the seven uniformed services – can you name the other five?) NOAA Corps officers are in command on all of the active NOAA commissioned ships and aircraft and you will learn a lot more about them in future posts. The PHS is an organization made up primarily of medical professionals. These folks serve in various medical and medical research positions around the nation. There are many who will work for the National Institutes of Health in research, or the Bureau of Prisons or commissioned vessels like Fairweather as practitioners. Unlike NOAA Corps, PHS is not on a billet cycle where every two to three years you will be moved to a new position in a different office or location. Similar to all of the other uniformed services, though, promotion through the ranks is both encouraged and desired.

Traditional Boat - Nome

As we walked all around Nome, this was one of the sights – the frame of a traditional fishing boat.

We also saw the marker for the end of the Iditarod race. I was able to see the historic beginning in Seward, Alaska back in 2010, so seeing the end in Nome was an unexpected treat. Nome also has Cold War-era missile early warning system arrays at the top of a mountain nearby. We had a chance to hike around them and see some of the interesting geologic features of the area. There’s so much more to talk about, but I think I’ll stop here and save shipboard life for my next post.

Did You Know…

… that the Iditarod has its historic beginnings with the Public Health Service? There were many children in interior and western Alaska dying of diphtheria in the early 1920s. When it reached epidemic proportions, the only doctor in Nome reached out to the PHS in the lower 48 to ask for help. Vials of serum were found and sent north to Seward, but then because of heavy ice and storming, dog sled teams were used to get the vials to the interior towns and to Nome. The original race along the Iditarod Trail was run as a memorial to the “Serum Run” and eventually evolved into the highly competitive race it is today.

Helen Haskell: Data Acquisition Through Small Boat Surveying, June 12, 2017

 

NOAA Teacher at Sea

Helen Haskell

Aboard NOAA Ship Fairweather

June 5 – 22, 2017

Mission: Hydrographic Survey

Geographic Area of Cruise: Southeast Alaska – West of Prince of Wales Island

Date: June 12, 2017

Weather Data:

Temperature: 13°C

Wind 12 knots, 230° true

10 miles visibility

Barometer: 1016 hPa

90% cloud cover at 2000 feet

Location:  Dall Island, AK  54° 54.5’N  132°52.1W

 

Science and Technology Log:

The role of the Fairweather is to conduct hydrographic surveys in order to acquire data to be used in navigational charts. While the Fairweather has sonar equipment and collects lots of data in transit, much of the data collected on a daily basis is by using smaller boats, with a rotating crew of 3-4 people per boat. The Fairweather will sail to the research area and drop anchor, and for multiple days crews will use these smaller vessels to collect the raw data in an area.

 

“Sonar” was originally an acronym for Sound Navigation and Ranging, but it has become a word in modern terminology. The boats contain active sonar devices used by the NOAA scientists to calculate water depth, document the rocks, wrecks and kelp forests, and in general, determine hazards to boats. Ultimately their data will be converted in to navigational charts – but there is a significant amount of work and stages to be undertaken to make this a reality.

Attached to the small boats are Kongsberg Multi Beam Echo Sounders (MBES). These devices emit sound waves in to the water. The waves fan out and reflect off the bottom of the sea floor and return to the MBES. Based on the time it takes for the MBES to send and receive the sound waves, the depth of the sea floor can be calculated. As the boat moves through the water, thousands of pieces of data are collected, and collectively a picture of the sea floor can be built.

IMG_0356

The pink line is the sea floor

It sounds simple, right? But I am beginning to understand more about the complexities that go in to a project of this scope. It would seem simple perhaps, to drive a boat around, operate the MBES and collect data. As I have quickly come to understand, there is a lot more to it.

As mentioned before, due to the weather conditions in the geographic area of study and routine maintenance, the Fairweather has a field season, and a dry dock season. During the non-field season time, data is analyzed from the previous seasons, and priorities and plans are made for the upcoming seasons. Areas are analyzed and decisions made as to which regions the Fairweather will go to and sheets are determined. A sheet is a region within the project area. Each sheet is broken up in to polygons. On any given day, one small boat will cover 1-3 polygons, depending on the weather, the complexity of the area, and the distance of travel from the Fairweather.

 

There are many parameters that the scientists need to consider and reconfigure to acquire and maintain accurate data collection. A minimum density of soundings (or ‘pings’) is required to make sure that the data is sufficient. For example, in shallow waters, the data density needs to be a minimum of five soundings per one square meter. At a greater depth, the area covered by the five soundings can be 4 square meters. This is due to the fact that the waves will spread out more the further they travel.

A coxswain will drive the boat in lines, called track lines, through the polygon. As the data is collected the ‘white chart’ they are working with begins to get colored in. Purple indicates deepest water. Green and yellow mean it’s getting less deep. Red indicates shallow areas, and black needs to be avoided. In the pictures below you can begin to see the data being logged visually on the map as the boat travels.

 

Make an analogy to mowing a lawn. There are areas of most lawns where it is easy to push the lawnmower in straight lines, more or less. The same can be said for here, to some extent. In the deeper waters, not close to shore, the boats can ‘color in’ their polygon using relatively wide swaths that allow the sonar data to overlap just slightly. Every time the boat turns to go back in the opposite direction, the MBES is paused, and then started again once the boat is in position, making a new track line. Close to the shore, referred to as near shore, there are usually more hazards. In these areas, speed is slowed. Due to the increased potential of rocks and kelp beds in an unknown area, the boats do something called half-stepping, in-effect overlapping the ‘rows’ – think about re-mowing part of that section of lawn, or mowing around tree trunks and flower beds. As a visual image comes up on the screen, the coxswain and the hydrographers can determine more where their next line will be and whether they should continue surveying that area, or if there are too many hazards.

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Data aquisition

Full coverage needs to be achieved as much as possible. At times this does not happen. This can be as the result of several factors. Kelp increases the complexity of data collection. Kelp often attaches to rocks, and there are large ‘forests’ of kelp in the areas being surveyed. As the sonar also ‘reads’ the kelp, it’s not possible to know the true location, size and depth of the rock the kelp is attached to, and in some instances, to determine if the kelp is free floating.

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Kelp

Steep slopes, rocks and kelp can also create ‘shadows’ for the MBES. This means that there are areas that no sounding reached. If possible the survey team will re-run a section or approach it from another angle to cover this shadow. At times, the rocky areas close to shoreline do not allow for this to be done safely.  A holiday is a term used by the survey crew to describe an area where data did not register or was missed within a polygon or sheet. During data collection, a day may be dedicated for boats to return to these specific areas and see if the data can be collected. On occasion, weather conditions may have prevented the original crew from collecting the data in the first place. Equipment malfunction could have played a role, as could kelp beds or hazardous rock conditions.

Survey crews are given several tools to help them navigate the area. Previous nautical charts are also superimposed on to the electronic chart that the surveyors are using. While many of these contain data that is out of date, it gives the crew a sense of what hazards in the area there may be. Symbols representing rocks and kelp for example are shown. The Navigable Area Limit Lines (NALL) are represented by a red line that can be superimposed on the map. Any area closer to shore than the NALL is not required to be surveyed.

 

 

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The red line is the Navigable Area Limit Line. Areas inland of this line do not need to be surveyed, as they are known to be entirely non-navigable.

On occasion, surveying will discover a Danger to Navigation (DTON). This might include a rock close to the surface in a deeper water area that is not shown on any map and which may pose imminent danger to mariners. In these instances these dangers are reported upon return to the Fairweather, and information is quickly sent to the Marine Chart Division’s Nautical Data Branch.

During the course of the day, the scientists are constantly checking the data against a series of parameters than can affect its accuracy. Some of these parameters include temperature, salinity of the water and the tide levels. More about these parameters will be discussed in later blog postings.

Personal log

The first part of the day involves the stewards getting coolers of food ready for the survey crew who will be gone all day. The engineers have fixed any boat issues from the previous day and re-fueled the boats and the deck crew have them ready to re-launch. A GAR score is calculated by the coxswain and the crew, to determine the level of risk for the days launch. The GAR score examines the resources, environment, the team selection, their fitness, the weather and the mission complexity. Each factor is given a score out of 10. Added up, if the total is 23 or less, the mission is determined ‘low risk’, 24-44 is ‘use extra caution’, and greater than 45 is high risk. On the first day I went on a boat, as a first timer, the GAR score was a couple of points higher in the ‘team selection’ section as I was new.

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Operational Risk Assessment Form

Another fascinating aspect of this research is the equipment on the ship needed to launch these small boats. Huge winches are needed to hoist the boats in and out of the water. Deck crew, with support from the survey crew are responsible for the boat hauling multiple times a day, and the engineers are on hand to fix and monitor the equipment.

After my first day out on the small boats, the data acquisition began not only to make more sense, but also my understanding of the complex factors that make the data collection feasible began to broaden. I had naively assumed that all the work was done from the Fairweather and that the Fairweather would be constantly on the move, rather than being anchored in one location or so for a few days. As we journeyed around small islands covered in Sitka spruce, I watched constant communication between the survey crew and the coxswain on the small boats. The survey crew are constantly monitoring the chart and zooming in and out so that the coxswain can get a better and safer picture of where to take the boat.   As well as watching the monitors and driving the boat, the coxswain is also looking ahead and around for hazards. There is a significant number of large floating logs ready to damage boats, and on occasion, whales that the boat needs to stay away from. It is a long day for all the crew.

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Bekah and Sam monitor the incoming data to communicate quickly with Nick, the coxswain.

Aside from learning about the data acquisition being on the small boat, one of the joys was to be closer to some of the wildlife. While I will go in to more detail in later entries, highlights included catching glimpses of humpback whales, families of sea otters, and harbor seal pups.

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Yes, I got to drive…in the purple area.

Fact of the day: 

While animals, such as bats, have been using sonar for thousands or millions of years, it wasn’t until the sinking of the Titanic that sonar devices were invented and used for the locating of icebergs.  During World War I, a French physicist, Paul Langévin, developed a tool to be able to listen for submarines. Further developments lead to sonar being able to send and receive signals. Since then, major developments in sonar technology have led to many different applications in different science fields.

Word of the day: Nadir

On small boat surveys, nadir is the term used to describe the ocean floor directly below the boat. It is the low point below the boat.   

What is this?

What do you think this is a picture of? (The answer will be in the next blog installment).

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(Answer from previous blog: part of a section of a dumbbell from the Fairweather workout room)

 

Acronym of the Day

HIC: Hydrographer In Charge

 

 

 

 

 

 

 

 

 

 

 

Jeanne Muzi: Problem Solving on the Thomas Jefferson! August 5, 2015

NOAA Teacher at Sea
Jeanne Muzi
Aboard NOAA Ship Thomas Jefferson|
August 2 – 13, 2015

Mission: Hydrographic Survey
Geographical area of cruise
: North Atlantic
Date: August 5, 2015

Weather Data From the Bridge:
Temperature: 71° F (22° C)
Humidity: 84%
Wind Speed: S 5 mph
Barometer: 29.89 in (1012.1 mb)
Dewpoint: 66° F (19° C)
Visibility: 10.00 mi

Hello again!

Science and Technology Log:

One important thing that every single person has to face, no matter how old they are or what kind of job they have, is what to do when things go wrong. We are always happy when things are going smoothly—but what do you do when they don’t?

I found out about how important it is to be a thinker and problem solver on the Thomas Jefferson because we are experiencing engine problems. First the launches were not running. Then the TJ’s engines were having difficulties and it was discovered that we had water in our fuel. The engineers and officers all started to ask questions: Where is the water coming from? Is there a problem with the tanks? How are we going to fix this situation? What is the best solution right now? It was determined that we should sail into the Naval Base in Newport, Rhode Island so the fuel could be pumped out and the fuel tanks examined. This is a big job!

Heading to Newport

Lighthouse

Jamestown Bridge

Jamestown Bridge

We sailed into Newport on a beautiful sunny afternoon. I got to spend some time on the bridge and watched as Ensign Seberger and GVA (General Vessel Assistant) Holler steered our large ship around obstacles like lobster pots and small sailboats. AB (Ablebodied Seaman) Grains acted as the look out, peering through binoculars and calling out directions in degrees (instead of feet or yards), and port and starboard (instead of left and right). LTJG Forrest explained how to chart the route to Newport using a compass, slide rule and mathematical calculations. His computations were right on as he plotted the course of the Thomas Jefferson. 

Charting TJ's course to Newport

Charting TJ’s course to Newport

When we arrived at Newport, the tugboat, Jaguar, needed to help us dock and then the gangway was lifted into place using a crane.

The tugboat arrives to assist the TJ.

The tugboat arrives to assist the TJ.

The tugboat Jaguar helping the TJ dock at Newport

The tugboat Jaguar helping the TJ dock at Newport

The walkway is lowered from ship to shore.

The gangway is lowered from ship to shore.

Now we are waiting in Newport to see how the ship will be repaired, and how that will impact the surveying mission and the work of all the scientists on board. The fuel is currently being pumped out of the tanks so the engineering department can figure out what is going on.

Personal Log:

Some of my students have emailed to ask where am I sleeping. When you are aboard a ship, you sleep in a stateroom. I have the bottom bunk and my roommate has the top. We have storage lockers and shelves to hold our stuff. The bathroom (called the head) connects our stateroom with another room.

Bunks in our stateroom

Bunks in our stateroom

Everyone eats in the Mess. You pick up your hot food on a plate in front of the galley and then sit down to eat at a table. Some of our meals so far have been omelets and cereal for breakfast, shrimp, rice and vegetables for lunch, and fish and potatoes for dinner. There is always a salad bar. Yogurt and ice cream are available, along with lots of different drinks.

Everyone eats meals together in the mess.

Everyone eats meals together in the mess.

The passageways are pretty narrow around the ship and the stairs going from one deck to another are steep whether you are inside or outside.

Lots of ups and downs outside...

Lots of ups and downs outside…

Lots of ups and downs inside

Lots of ups and downs inside…

 

Everything on a ship must be well-organized so equipment can be found quickly and easily.

Equipment must be organized so everyone can get what they need.

Equipment must be organized so everyone can get what they need.

The view from the outside deck has been beautiful…

There is always something to see on the TJ

There is always something to see on the TJ

The last Question of the Day was: What do the letters XO mean on the hardhat of the person in the center of this picture?

XO Stands for Executive Officer

XO Stands for Executive Officer

XO stands for Executive Officer. Our Executive Officer is Lieutenant Commander Olivia Hauser. She is the second in command on board.

The last Picture of the Day showed this image:

Whale caught with sonar

Whale caught with sonar

This image was captured with sonar and shows a whale swimming in the ocean. Amazing!

Today’s Question of the Day is:

Why is surveying the ocean floor so important?

Today’s Picture of the Day is:

What is this and what is it used for?

What is this and what is it used for?

What is this?

Thanks for reading this entry.

Windy day on the deck of the TJ

Windy day on the deck of the TJ

Yaara Crane: My Morning on a Survey Launch, June 26, 2013

NOAA Teacher at Sea
Yaara Crane
Aboard NOAA Ship Thomas Jefferson
June 22, 2013 – July 3, 2013

survey boat on TJ

The survey boat is moving from its cradle on the deck of the TJ.

Mission: Hydrographic Survey
Geographical area of cruise: Mid-Atlantic
Date: Wednesday, June 26, 2013 

Latitude: 38.84°N
Longitude: 75.04°W

Weather Data from Bridge:
Wind Speed: 8.35 knots
Surface Water Temperature: 21.29°C
Air Temperature:  22.80°C
Relative Humidity: 82.00%
Barometric Pressure: 1011.36mb

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The survey launch on its way

Todd and Yaara

I am talking with the HIC about the notations on the nautical chart for our survey grounds.

Science and Technology Log

As promised, today’s post is going to be about the Hydrographic Survey Launches. The Thomas Jefferson has two of these boats that are generally launched by 8:00am and return to the ship at 5:30pm. On Tuesday, my official role was Hydrographer in Training. I joined HIC Todd and Coxn Junior for a day of surveying on boat 3102. After a morning of seasickness, they returned me to the TJ around 11:30 to recuperate. However, I was still able to experience a little of what they do every day and the hilarious camaraderie between the two!

In general, the survey launches do the same work as the Thomas Jefferson, just on a smaller scale. The TJ can only drive on lines with a minimum depth of 30 feet, but the survey launches can go to a minimum depth of 12 feet which allows them to get much closer to shoals and the coast. Every morning, the launch survey teams have a meeting with the FOO and XO in the survey room to discuss logistics and safety. My boat was headed out to survey grounds on a new sheet near Cape May, New Jersey. Specifically, we were driving lines in the Prissy Wicks Shoal. This particular region has highly variable depths and created quite a challenge for the HIC and Coxn for two reasons: you cannot navigate in straight lines over shoals, and the shoals constantly change so you must drive slowly in case an area is shallower than charted.

HIC Todd

Todd is at his workstation in the cabin.

Todd has been a HIC for both the Rainier and the Thomas Jefferson. In this position, he was worked with many Teachers at Sea, and gave me lots of great resources to bring back to school. The HIC sits inside the cabin and makes sure that all of the equipment is working together and logging the correct data. Just like on the ship, he has an MBES, HYPACK, and POS-MV to help him do his job. However, unlike the ship, he does not have an MVP, and must launch a CTD every four hours to measure the sound velocity profile in the water column. Measuring the sound velocity profile is an important part of correcting the MBES data for improved accuracy. Remember, the equipment is very sensitive to changes in the water because the farther the sound waves travel, the more they are affected by changes in the density of the medium through which they travel.

Coxn

Junior is doing his best to keep us on the line

Junior’s job as Coxn is to work with the HIC to safely navigate the boat on the survey lines. The Coxn has a monitor controlled by the HIC to help him see the current chart and line. Junior gave me the opportunity to try driving, and I barely lasted 15 seconds before I was off the line! Tuesday was particularly complex because we were in a highly trafficked waterway, shoals appeared out of nowhere, and there was a very strong current around the cape. When another boat appears in the line, the Coxn must bring his boat to a standstill while staying on the line so that data collection does not have to stop. If the survey line goes over an area that is particularly shallow, a decision needs to be made about how to get around the shoal without hitting the bottom. A lot of good-natured yelling happens between the Coxn and HIC so that they can hear each other and be in constant communication.

Once the survey launch has returned to the main ship, the data is downloaded onto a server from which the hydrographers can move the data into CARIS. Eventually all of that data will be turned into a new nautical chart to help marine vessels maneuver through the waters.

survey lines

What looks like highlighting is the multi-beam data from the survey launches. The colors get warmer (red) as the depth gets shallower

Today’s Acronyms and Abbreviations (some old, some new)

HIC – Hydrographer in Charge

Coxn – Coxswain

FOO – Field Operations Officer

XO – Executive Officer

MBES – Multi-Beam Echo Sounder

MVP – Moving Vessel Profiler

HYPACK – Surprise, not an acronym! This is just the name of the software.

POSMV – Positioning Orientation System Marine Vessel

SSS – Side Scan Sonar

CTD – Conductivity, Temperature, and Depth

CARIS – Computer-Aided Resource Information System. This software allows scientists to process the data that comes from HYPACK. Hypack collects data one line at a time, while CARIS allows you to combine the lines into a new nautical chart.

Prissy Wicks

The chart of Prissy Wicks Shoal shows the extreme changes in depths in a very small area.

Personal Log

Well, my bout of seasickness started about half an hour into my time on the survey launch. I started off in the cabin with the HIC, and the swells in the water got to me immediately. I spent the rest of the time on the deck with the Coxn trying to keep my eyes on the horizon. Through it all, I still managed to get a glimpse of some dolphins playing in the swells and saw many different types of boats and ships sailing around. When I was returned to the ship, I immediately felt better. However, the medical officer took precautionary measures and measured my blood pressure (totally normal, as usual for me) and prescribed 1.5 Liters of water before bed for the night. I took a nice long nap, and woke up in time for a delicious vegetable casserole for dinner. I am feeling back to 100% today, and hope to stay awake tonight. The TJ runs 24 hour operations, so I will pop by the bridge and survey rooms to see what it looks like after dark.

emergency signal

This sign is placed in each room as a reminder of what to do in case of emergencies.

Did You Know?

While at sea, it is required to perform at least one safety drill a week. Today, we had a fire drill and an abandon ship drill.

abandon ship suit
As part of my safety orientation, I had to put on the survival suit. I think I need a smaller size…

muster

My assigned muster locations for emergencies.