Exploring the seas, via IP
Okeanos Explorer uses a satellite link to provide scientists with ocean-going data
- By William Jackson
- Sep 28, 2008
THE OKEANOS EXPLORER is something of a throwback to the Age of Discovery, when ships sailed the seas on missions of exploration rather than dedicated research. But it has a twist: The Okeanos will use the latest communications technology to explore the oceans and confer with scientists onshore in near-real time.
The National Oceanic and Atmospheric Administration commissioned the Okeanos, which is the Greek word for ocean and pronounced with a hard 'k,' in August. It is a converted Navy surveillance vessel and the first U.S. ship dedicated to ocean exploration.
'IP plays a very important part,' said Webb Pinner, a systems engineer at NOAA's Office of Ocean Exploration and Research. 'That's the medium through which telepresence works.'
Telepresence refers to the ship's system for live, near-real-time audio, video and data transmission via satellite and Internet2 to five Exploration Command Centers that will give onshore scientists the ability to participate in the ship's mission.
'With telepresence, we're no longer crowding the ship with scientists,' said Fred Gorell, a spokesman at the Office of Ocean Exploration and Research. 'There will be scientists on the ship, but they will be more technicians running the equipment.'
Telepresence will enable shore-side scientists to be available as needed at the following command centers:
- The Inner Space Center at the University of Rhode Island.
- The Center for Coastal and Ocean Mapping/ Joint Hydrographic Center at the University of New Hampshire.
- The Mystic Aquarium and Institute for Exploration in Connecticut.
- NOAA's Pacific Marine Environmental Laboratory in Seattle.
- NOAA's Science Center in Silver Spring, Md.
NOAA's Office of Marine and Aviation Operations has a sea and air fleet that includes a number of research vessels. But exploration missions are distinct from research, which is conducted with a specific goal, tests hypotheses and builds on data already discovered. Grants typically fund research missions.
Exploration is more open-ended and encompasses searches for anomalies and new information that researchers can follow up on later. Okeanos will gather a representative sampling of data from interesting discoveries and leave the exhaustive studies to researchers.
Because of the nonspecific nature of the mission ' there is no way of knowing what the ship will encounter ' it is crucial to have scientists on call rather than onboard. When NOAA discovered tube worms in hydrothermal vents, a new form of marine life, off the Galapagos Islands in 1977, no marine biologists were aboard the vessel. Today, biologists will be able to examine new discoveries remotely via a video feed and advise personnel aboard the ship on their significance.
'You have the best scientists at the right time in the right place,' Gorell said.
Another difference between exploration and research is that grant-funded research data typically belongs to the scientists who create it. By contrast, the Okeanos' discoveries will be public information.
Okeanos was launched in 1988 as USNS Capable; it performed submarine and air surveillance and drug interdiction. Its designation as a U.S. naval ship meant that civilians, rather than military personnel, largely staffed and ran it. The vessel was transferred to NOAA in 2004, and during the next four years, the agency refitted it for ocean exploration. It was re-commissioned last month, and after testing at sea, the ship is expected to begin its first full field season in 2009, during which it will spend two years in the Pacific Ocean.
Its equipment includes a first-of-its-kind hull-mounted multibeam sonar mapping system that can produce detailed 3-D maps of the ocean floor at depths of 4,000 meters. It will use a remote operated vehicle (ROV) to examine anomalies. That tethered system includes a high-definition camera sled that watches the main vehicle below it. The main vehicle also carries high-definition cameras and lights, sensors, manipulators, and a small 60-pound xBot that will be sent into areas where it would be difficult or unwise to send the main vehicle.
'The 'x' in xBot stands for expendable,' Pinner said.
To keep the ship in place while the ROV is deployed, a dynamic positioning system integrates satellite data with the ship's engines and thrusters to keep it stationary to within about five meters.
Data collected by the systems will be sent to shore-based facilities via a 3.7-meter very-small-aperture terminal satellite link. SeaMobile Enterprises' MTN Satellite Services is providing satellite communications under a three-year contract for the NOAA fleet. The link provides up to 45 megabits/sec of throughput, although NOAA is paying for 20 megabits/sec for Okeanos. The signal is beamed to a ground station in California that is connected to the NOAANet Multiprotocol Label Switching network.
Because the five Exploration Command Centers established by NOAA are not on the agency's network, data is delivered to them via Internet2, the United States' high-performance research and education network. The link will offer 16 audio channels and three video channels with embedded audio.
Each command center has three large plasma screens for simultaneous video feeds from Okeanos ' two for video from the ROV and camera sled and a third for video from the ship's other cameras and sensors. Data from the ship's computer screens can also be sent as video so scientists can see data generated by the mapping sonar and navigation systems. The command centers use Tandberg video decoders.Multicast system
The telepresence system will capitalize on Internet2's multicast capability to reduce bandwidth requirements. Unlike the Internet's standard unicast technology, multicast allows a single data stream to be sent to multiple endpoints.
'With multicast, it doesn't matter whether you have one user or 100, it uses the same amount of bandwidth,' Pinner said.
Although the command centers are interoperable, the Inner Space Center acts as the system's hub. It is unlikely that the appropriate specialists will be available at all facilities, so centers will typically take the lead in specific areas. For example, researchers at the University of New Hampshire center will likely be primarily involved in mapping activities.
Although scientists at the onshore centers will be able to call the shots ' or at least make suggestions ' for the ROV, physical control of the vehicle will be in the hands of engineers aboard the ship because of the 0.75-second delay in video between ship and shore.
As many as 360 hours of video can be archived onboard Okeanos. The ROV control room has 16 video screens, not including computer monitors. The control room is divided into an engineering side and a science side because 'what science wants and what engineering needs to safely run the vehicle sometimes clash,' Pinner said.
Audio communication in the ship's control room and with the command centers onshore will take place via the 16 channels of the RTS digital intercom system from Telex Communications. Having everyone use intercom headsets reduces the amount of cross-chatter and makes it easier to converse, Pinner said.
An unexpected benefit of the intercom system is a more peaceful work environment, he added. 'It helps calm everyone by not having to raise your voice to be heard.'
It is impossible to predict just where Okeanos will go and what it will find. 'It's a big ocean,' Gorell said. 'It's 95 percent unknown.'