Tag Archives: node buoys

Even the Oceans are not Free: Swarming the Seas

The Ocean of Things of Defence Advanced Research Projects Agency (DARPA) aims to  wire up the high seas with swarms of floating, connected sensors.  Such devices are not in themselves new. There are around 6,000 floating sensors deployed around the world’s oceans, run by navies and research institutes. What is unprecedented is the scale of  DARPA’s ambition. Over the next few years it hopes to deploy 50,000 sensors across 1m square kilometres of sea, an area considerably larger than Texas. The eventual goal—much more distant—is to enable the continuous monitoring and analysis of a significant fraction of the world’s oceans.

Existing “floating instrument packages”, known as floats or drifters, are often custom-built, and usually contain the highest-quality instruments available. They therefore tend to be expensive, and are bought only in small numbers. A typical existing float, designed for scientific research, is the Argo. It costs around $20,000, and can measure water temperature and salinity.  The Ocean of Things takes the opposite approach. The aim is to cram as many cheap, off-the-shelf components as possible into a single low-cost package. Current float prototypes cost around $750…That would allow tens of thousands to be deployed without breaking the bank. Large numbers are crucial for coverage. They also help compensate for inaccuracies in individual instruments.

The project’s researchers are evaluating three designs from different manufacturers, ranging in size from about six to 18 litres. One, proposed by Xerox’s Palo Alto Research Centre, is made of glass, like a traditional Japanese fishing float. A second, from a firm called Areté Associates, has an aluminium shell, and uses wood for buoyancy. Both models feature solar panels. The third, made by a company called Numurus, is made of lacquered cardboard, and relies entirely on its batteries. All three are designed to last for a year or so and are made to be as environmentally friendly as possible, with minimal use of plastics. That is important because, at the end of their mission, the floats are designed to scuttle themselves

With 361m square kilometres of ocean on the planet, a true Ocean of Things, monitoring everything on and under the water, would require about 18m floats.

Excerpts from Big Wet Data: The Ocean of Things, Economist, Mar. 14, 2020

Undersea War Networks: DARPA Tuna

DARPA’s Tactical Undersea Network Architecture (TUNA) program completed its initial phase, successfully developing concepts and technologies aimed at restoring connectivity for U.S. forces when traditional tactical networks are knocked offline or otherwise unavailable. The program now enters the next phase, which calls for the demonstration of a prototype of the system at sea.

TUNA seeks to develop and demonstrate novel, optical-fiber-based technology options and designs to temporarily restore radio frequency (RF) tactical data networks in a contested environment via an undersea optical fiber backbone. The concept involves deploying RF network node buoys—dropped from aircraft or ships, for example—that would be connected via thin underwater fiber-optic cables. The very-small-diameter fiber-optic cables being developed are designed to last 30 days in the rough ocean environment—long enough to provide essential connectivity until primary methods of communications are restored.

Supplying power to floating buoy nodes on the open sea presents a particular challenge. During the first phase of the program, the University of Washington’s Applied Physics Lab (APL) developed a unique concept called the Wave Energy Buoy that Self-deploys (WEBS), which generates electricity from wave movement. The WEBS system is designed to fit into a cylinder that could be deployed from a ship or aircraft.

Excerpt from Networks of the Sea Enter Next Stage, DARPA website, Jan. 5, 2017