Tag: hydrophone

NOAA Teacher at Sea
Marsha Skoczek
Aboard NOAA Ship Pisces
July 6 – 19, 2012

 

Mission: Marine Protected Areas Survey
Geographic area of cruise:  Subtropical North Atlantic, off the east coast of North Carolina
Date:  July 13, 2012

Location:
Latitude:  33.26104N
Longitude:  76.54810W

Weather Data from the Bridge
Air Temperature:  28.1C (82F)
Wind Speed:  4.5 knots (5.2mph)
Wind Direction:  From the SSE
Relative Humidity: 78 %
Barometric Pressure:  1021.1
Surface Water Temperature:  28.1C (82F)

Science and Technology Log

Rather than fishing for multiple samples of each species from every Marine Protected Area (MPA) we stop at, the scientists opted to use a Remotely Operated Vehicle (ROV) to gather their data.  This also allows Stacey Harter and Andy David to get real time footage of the animals that inhabit each dive site as well as a more complete picture of the habitat itself.  Not only are we collecting data on the fish, but John Reed and Stephanie Farrington are taking data on all of the invertebrates we see such as sponges, corals, hydroids, crinoids, sea stars, urchins, and lobster. The ROV we are using for this expedition is called the Phantom S2.  It weighs about 300 pounds when out of the water with the dimensions of 24 inches in height, 55 inches in length and 33 inches in width.  The Phantom S2 uses the tether to power the two ½ horizontal horsepower electric motors and the two vertical 1/4 vertical horsepower motors and has a maximum speed of 2 knots (2.3mph) and because of the length of the tether, is limited to a depth of 1000 feet.  The ROV is equipped with a high resolution video camera with a 12x zoom as well as a digital still camera with strobe to collect high quality color images of anything the scientists need for their research.  On this cruise we are averaging about 450 still images and about seven hours of video daily.  Two lasers mounted at 10 cm wide help the scientists measure specimens without bringing them to the surface.

Setting up the ROV onboard the ship takes about a day.  This requires the ROV team of Lance Horn and Glenn Taylor from the Undersea Vehicles Program out of University of North Carolina Wilmington to arrive at least 24 hours in advance of departure so that they can have the ship’s crew load all of the ROV equipment with the crane.  From there they set up the components in the dry lab and begin running the tether cables from the ROV, which is located on the deck, to the computer, which is located in the dry lab.  We also have to run a line up to our GPS device  and our VHF radio that are both installed on the flying bridge, and yet another cable to transfer the digital images to the computer, and the power line for the ROV engines.  Once the research gets underway, it is not uncommon for Lance and Glenn to spend as many as 12 hours a day working on preparing for the dive, operating the equipment during the dive, and then processing all of the data after the dive.  It is hard work and takes great attention to detail.

In order to communicate with the ROV while it is underwater the operators deploy a Trackpoint hydrophone over the side of the ship which must be taller than the hull of the ship, which on the Pisces is over 28 feet tall.  This hydrophone picks up the X,Y,Z coordinates from the ROV then uses the data from antenna mounted on the fly bridge of the ship to create GPS coordinates for the ROV.

This information is plotted into the Hypack mapping system and is used by both the ROV driver as well as the bridge of the ship.  This helps the officer on deck know what heading the ship needs to be traveling so the ROV driver can maneuver the ROV to where the scientists want to go. Depth is calculated by the delay in time that it takes the hydrophone to get a signal from the ROV.

Driving the ROV takes great skill and concentration.  Not only do you have to watch the ROV display footage to make sure you don’t run into anything, but you also have to constantly be aware of your heading so you don’t get the ROV too far off course.  The tether keeping the ROV in communication with the ship also has to be monitored.  Getting the tether wrapped around a rock overhang or part of a mast on a shipwreck is of great concern.  If the tether is severed or becomes too entwined, the ROV could be lost.  The ROV driver is in constant contact with the crew on the back deck who are watching the tether line as well as the bridge so that any necessary course corrections can be made quickly and efficiently.  Having too much tether in the water can also lead to tangling, so the tether is marked in 50 foot increments, which allows the deck crew to know how much of the tether line to feed into the water.  On our cruise, the longest the ROV has been below the surface has been 3.5 hours. Because of the intense concentration it takes to drive the ROV, four consecutive hours is the limit that a driver can do in one sitting.  If the dive needs to be longer than four hours, Lance and Glenn would trade duties, so if Lance was driving, he would rotate out onto the deck to monitor the tether while Glenn takes over at the controls.

The ROV requires three consoles of components to operate.  The first is the ROV control console.  This is where the driver controls the ROV itself.  On this panel are the two joysticks that control the movement of the ROV through the water.  The joystick on the left controls the up, down and side to side motion.  The joystick on the right controls the forward, reverse, as well as left and right.  There are also control switches to tilt the camera so that it is hanging vertically within the cage to take pictures of the ocean floor.

The scientists on this cruise want a “bottom” shot every two minutes.  This is their way of “collecting” random samples of the habitat while we are making our way along the transect line.  There are also controls switches to turn on and off the lights, turn on and off the laser, and to switch over from the video camera to the still camera so digital still pictures can be taken.  Directly above the control panel is a flat screen monitor showing the live footage from the ROV so the pilot can see where the ROV is below the surface.

The middle console has all of the navigation components.  There is a GPS unit displaying the coordinates of the ship at all times.   It also contains a Trackpoint acoustic tracking system that provides position data for the ROV.  This is not only helpful to the driver, but the scientists take waypoints throughout the operation to help them match up the data they recorded while watching the live video feed from the ROV with the still images, and the temperature and depth data taken by a small CTD attached to the ROV cage.

Also on this cabinet is a rackmount computer using Hypack software.  The scientists can load the multibeam sonar information and the transect coordinates into the navigation computer.  This software gathers and logs information from the ROV as well as other navigational electronics so the driver sees a real time image of where the ROV is in relation to the ship and features of interest on the sea floor.  This also gives both the driver and the scientists an idea of where we are in relation to the transect line.  If multibeam images were available and downloaded into the navigation computer, the chief scientist can use those to adjust our heading off the transect line if she feels the structures they need to study are on a different heading than originally plotted.

The third console contains the controls for the digital still camera as well as the digital recording devices.  Steve Matthews, part of the science team, has been manning the still photography on this cruise.  When the scientists see something they want a close up picture of, they ask the driver to stop the ROV and position it so the still camera can be zoomed in for a close up shot.  This will help the scientists to make the proper identification of all of the different species we photographed while on this cruise.

For this research trip, video and still images are all the scientists need to assess the efficacy of the MPAs.  The Phantom S2 has other tools that can be used depending on how the scientist needs to collect their data.  The ROV can be fitted with a sonar device which can be used to located objects, such as ship wrecks or other lost items, at ranges farther away than the video can see.  Scientists can also elect to use the claw for sample collection, a plankton net to gather plankton, and a fish collection suction device.

Personal Log

The bottom of the ocean has such incredible diversity!  Before being invited to be a part of this research expedition, I had only read about all of the amazing things we have seen in text books.  The ROV has allowed us to travel to depths that are inaccessible to recreational scuba divers and to visit sites that not too many other people have been to.  Every day we see different species and habitats.  It is interesting to compare areas that are inside the MPAs with those that are outside of the MPAs.  Even though each day might seem like we are doing the same thing over and over again, I am anxiously awaiting a glimpse of something that I have never seen before.  For each depth we dive to, there is a new set of species and habitat to learn about.  The deepest dive we have been on so far this cruise was at the Snowy Wreck MPA at about 25 m (833 ft) below the surface.  This location was really cool because there is an old ship wreck here that is full of corals and anemones and all sorts of fish species.  We also had a little fun while at the depth and shrunk some styrofoam cups.  Stephanie Farrington is an amazing artist and designed these fabulous cups for us each to send down to shrink.

Ocean Careers Interview

In this section, I will be interviewing scientists and crew members to give my students ideas for careers they may find interesting and might want to pursue someday.  Today I interviewed Lance Horn and Glenn Taylor, ROV operators from University of North Carolina Wilmington (UNCW).

Mr. Horn, what is your job title?  I am the operations director of the Undersea Vehicles Program at University of North Carolina Wilmington.  I started at UNCW in 1985 as part of NOAA’s Underwater Research Center (NURC)  as a hard hat diver.  In 1987, I joined UNCW’s scuba and ROV program which has now become the Undersea Vehicles Program.

What type of responsibilities do you have with this job?  As director, I am in charge of lining up jobs for us, maintaining the budget, and finalizing the contracts from each project.  I also pilot and maintain the ROV itself.

What type of education did you need to get this job?  I graduated from the Florida Institute of Technology with an Associate’s Degree in Underwater Technologies.  In this program, we studied compressors, hydraulics, welding, scuba and underwater photography.

What types of experiences have you had with this job?  This job has allowed me to travel all over the world and to see some really cool things under the ocean’s surface.  My favorite ROV dive so far was when I went to Antarctica to map the trash dumped at the bottom of Winter Quarters Bay.  Before people realized what kind of impact indiscriminately dumping their trash overboard was doing to the habitats on the ocean floor, ships used to come into port at Winter Quarters Bay and dispose of their trash in the ocean.  This includes very large items such as 55 gallon drums, fire hoses, conex boxes, and even a bulldozer that fell through the ice!  My job was to use the ROV to create a map showing the location of the large objects so that it could be determined if it would be possible to recover these items for proper disposal.  As part of this project, we also had to take the ROV outside of the bay to have an undamaged habitat to use as a control variable for comparison with the bay.  Outside of the bay was amazing.  We were diving under six feet of ice and got to see an environment that not many others have seen, including purple worms, white sponges, and anemone.  It was beautiful.

What advice do you have for students wanting a career with ROVs?  Not every job requires a four year degree.  You can still find a good job doing something you love. I have been successful doing what I do with a two year Associate’s Degree.  Florida Institute of Technology was not an easy school.  I worked hard to earn my degree.

Mr. Taylor, what is your job title?  I am an ROV pilot and technician with the Undersea Vehicles Program and UNCW.

What type of responsibilities do you have with this job?  In addition to piloting the ROV, my primary responsibilities are to maintain the three console units that house all of the digital equipment we need to control the ROV.  This includes any rewiring that needs to be done or the replacement of equipment either for repairing broken parts or upgrading to newer electronics.

What type of education did you need to get this job?  I earned my Bachelors Degree from Clarkson College of Technology.  I went to work for General Electric in New York.  I was transferred to GE in Florida after which I decided to retire from GE and become a scuba dive master.  I went to work for NURC in St. Croix but was transferred to UNCW when the St. Croix office was closed.  This is where I hooked up with Lance in 1993 and learned to operate the ROV.

What types of experiences have you had with this job?  I have also been fortunate enough to travel the world with the ROV.  Diving at the Edisto MPA this week is probably the highlight of my career in ROV operation.  The reef features were fantastic, the water was clear, we had hardly any current, the ship was able to remain on course.  It was perfect conditions.

What advice do you have for students wanting a career with ROVs?  First and foremost, follow your passion.  What do you get excited about?  I have been driving ROVs for almost ten years and I still love coming to work each day.  To be successful in this field, you need a strong background in computers and technology.  You can be trained to drive the ROV, but strong technology skills are essential.  Another good skill to have is problem solving and trouble shooting.  Things might go wrong in the middle of a dive, you have to be able to figure out a solution right there on the spot to keep the dive going.