Swarm of underwater robots mimics ocean life

Underwater robots developed by researchers at Scripps Institution of Oceanography at the University of California San Diego offer scientists an extraordinary new tool to study ocean currents and the tiny creatures they transport.

Swarms of these underwater robots helped answer some basic questions about the most abundant life forms in the ocean—plankton.

The new study published in the Jan.
24 issue of the journal Nature Communications.

From Scripps

Underwater robots developed by researchers at Scripps Institution of Oceanography at the University of California San Diego offer scientists an extraordinary new tool to study ocean currents and the tiny creatures they transport.
Swarms of these underwater robots helped answer some basic questions about the most abundant life forms in the ocean—plankton.

Scripps research oceanographer Jules Jaffe designed and built the miniature autonomous underwater explorers, or M-AUEs, to study small-scale environmental processes taking place in the ocean.
The ocean-probing instruments are equipped with temperature and other sensors to measure the surrounding ocean conditions while the robots “swim” up and down to maintain a constant depth by adjusting their buoyancy.
The M-AUEs could potentially be deployed in swarms of hundreds to thousands to capture a three-dimensional view of the interactions between ocean currents and marine life.

 A group shot of the M-AUEs in Jaffe’s lab, awaiting deployment.
Credit: Scripps Institution of Oceanography

In a new study published in the Jan. 24 issue of the journal Nature Communications, Jaffe and Scripps biological oceanographer Peter Franks deployed a swarm of 16 grapefruit-sized underwater robots programmed to mimic the underwater swimming behavior of plankton, the microscopic organisms that drift with the ocean currents.
The research study was designed to test theories about how plankton form dense patches under the ocean surface, which often later reveal themselves at the surface as red tides.
“These patches might work like planktonic singles bars,” said Franks, who has long suspected that the dense aggregations could aid feeding, reproduction, and protection from predators.

Two decades ago Franks published a mathematical theory predicting that swimming plankton would form dense patches when pushed around by internal waves—giant, slow-moving waves below the ocean surface.
Testing his theory would require tracking the movements of individual plankton—each smaller than a grain of rice—as they swam in the ocean, which is not possible using available technology.

Miniature autonomous underwater explorers 
A video of the deployment of the M-AUE drifters at sea.

Jaffe instead invented “robotic plankton” that drift with the ocean currents, but are programmed to move up and down by adjusting their buoyancy, imitating the movements of plankton.
A swarm of these robotic plankton was the ideal tool to finally put Franks’ mathematical theory to the test.
“The big engineering breakthroughs were to make the M-AUEs small, inexpensive, and able to be tracked continuously underwater,” said Jaffe.
The low cost allowed Jaffe and his team to build a small army of the robots that could be deployed in a swarm.

Tracking the individual M-AUEs was a challenge, as GPS does not work underwater.
A key component of the project was the development by researchers at UC San Diego’s Qualcomm Institute and Department of Computer Science and Engineering of mathematical techniques to use acoustic signals to track the M-AUE vehicles while they were submerged.

 A graphic representation of the underwater explorers off the coast of Del Mar.

Credit: Jaffe Lab for Underwater Imaging/Scripps Oceanography

During a five-hour experiment, the Scripps researchers along with UC San Diego colleagues deployed a 300-meter (984-foot) diameter swarm of 16 M-AUEs programmed to stay 10-meters (33-feet) deep in the ocean off the coast of Torrey Pines, near La Jolla, Calif.
The M-AUEs constantly adjusted their buoyancy to move vertically against the currents created by the internal waves.
The three-dimensional location information collected every 12 seconds revealed where this robotic swarm moved below the ocean surface.

 A video that illustrates the trajectories of the M-AUE vehicles over the 5 hour experiment that was performed offshore of Torrey Pines, San Diego, on Oct 1, 2013.

The results of the study were nearly identical to what Franks predicted.
The surrounding ocean temperatures fluctuated as the internal waves passed through the M-AUE swarm.
And, as predicted by Franks, the M-AUE location data showed that the swarm formed a tightly packed patch in the warm waters of the internal wave troughs, but dispersed over the wave crests.
“This is the first time such a mechanism has been tested underwater,” said Franks.

The experiment helped the researchers confirm that free-floating plankton can use the physical dynamics of the ocean—in this case internal waves—to increase their concentrations to congregate into swarms to fulfill their fundamental life needs.
“This swarm-sensing approach opens up a whole new realm of ocean exploration,” said Jaffe.
Augmenting the M-AUEs with cameras would allow the photographic mapping of coral habitats, or “plankton selfies,” according to Jaffe.

An animation of the high-frequency internal wave temperature anomalies moving through the M-AUE swarm during a deployment offshore of Torrey Pines, San Diego, on Oct 1, 2013.

The animation shows a plan view following the center of mass of the swarm.

The numbers show the locations of the individual M-AUEs.

The research team has hopes to build hundreds more of the miniature robots to study the movement of larvae between marine protected areas, monitor harmful red tide blooms, and to help track oil spills.
The onboard hydrophones that help track the M-AUEs underwater could also allow the swarm to act like a giant “ear” in the ocean, listening to and localizing ambient sounds in the ocean.

Jaffe, Franks, and their colleagues were awarded nearly $1 million from the National Science Foundation in 2009 to develop and test the new breed of ocean-probing instruments.

Links :

• UPI : Researches replicate ocean life with swarm of underwater robots 
• Phys : Swarm of underwater robots mimics ocean life

The first images from the new weather satellite just arrived, and they’re absolutely incredible

GOES-16 captured this view of the moon, as it looks across the Pacific Northwest on Jan. 15.

As with earlier GOES spacecraft, GOES-16 will use the moon for calibration.

 (NOAA/NASA)

From Washington Post by Angela Fritz

The satellite formerly known as GOES-R (so Prince, right?) has transmitted its first images back to Earth, and they are flooring.
From the details on the face of the moon to the incredible resolution of cumulus over the Caribbean, these first pixels portend a sunny future for NOAA’s new GOES-16 satellite.
Meteorologists are drooling.
This release coincides with the first day of the American Meteorological Society’s annual meeting. There are thousands of weather geeks in Seattle this week, and — at least on Monday — they’re all looking at this next-gen satellite imagery.
As we’ve written before, GOES-R satellite has six instruments, two of which are weather-related.
The Advanced Baseline Imager, developed by Harris Corp., is the “camera” that looks down on Earth.
The pictures it sends back will be clearer and more detailed than what’s created by the current satellites.

This composite color full-disk visible animation is from 1:07 p.m. EDT on January 15, 2017 and was created using several of the 16 spectral channels available on the GOES-16 Advanced Baseline Imager (ABI) instrument.

Seen here are North and South America and the surrounding oceans.
GOES-16 observes Earth from an equatorial view approximately 22,300 miles high, creating full disk images like these, extending from the coast of West Africa, to Guam, and everything in between.
The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing on-orbit testing.

The ABI can scan half the Earth — or the “full disk” — in five minutes.
If forecasters want to home in on an area of severe weather, it can scan that region every 30 seconds. Weather radars can’t even scan faster than six minutes.

 Clouds swirls about Mexico and Central America in this animation from GOES-16 captured on January 15, 2017.

The other weather instrument, the Global Lightning Mapper, will continuously track and transmit all lightning strikes across North America and its surrounding oceans.
Developed by Lockheed, it can detect the changes in light on Earth and thus the rate and intensity of lightning in thunderstorms and hurricanes.

Research has shown that lightning is an excellent early warning indicator for approaching severe storms and the development of tornadoes.

This data visualization shows actual lightning measurements captured by an array of ground-based lighting detectors capable of tracing how lightning propagates through the atmosphere and simulates how the GOES-R Geostationary Lightning Mapper will monitor atmospheric flashes.

This technology could provide critical minutes of valuable warning time in advance of approaching severe storms.

GOES-16 is expected to go operational in November, approximately one year after its launch.

 On the right, an image from GOES-13 and on the left, the first public image from GOES-16, both taken Jan. 15.

 This composite color full-disk visible image (on the left) was captured 1:07 p.m. ET on Jan. 15 using several of the 16 spectral channels available on the GOES-16 Advanced Baseline Imager.

The image shows North and South America and the surrounding oceans.

(NOAA/NASA)

Links :

• NOAA : NOAA’s GOES-16 satellite sends first images of Earth / GOES-16 image gallery
• NPR : 'Like High-Definition From The Heavens'; NOAA Releases New Images Of Earth
• National Geographic : Earth Shines in Dramatic New Pictures From Space 
• GeoGarage blog : Revolutionary weather satellite blasts off

 

How an obsessive sailor and his fitness trackers supercharged yacht racing

 A-Cat Sailing, Pegasus MotionX, sailing doesn't get better than this: Santa Cruz perfection! 

From Wired by Philippe Kahn

It was an hour before the start of the race, and Philippe Kahn was in a state of panic.
He was sailing straight for the starting line off Point Fermin, just south of Los Angeles, and the hydraulic system on Pegasus, his 50-foot open-format yacht, had just failed.

Kahn was about to embark on the 2009 Transpac, the infamous, century-old sailing race that takes the bold and well-fixed from the Californian coast to the shores of Honolulu.
It’s a voyage through more than 2,500 miles of unsettled seas and gusting winds.
And without hydraulics to control the boat’s stabilizing canting keel, Kahn didn’t have a chance in hell of keeping her upright.

 Pagasus racing

Fifty minutes later, one of the boat’s two hydraulic rams was back up.
It would have to do.
And with just a few more hiccups along the way, the light-handed Pegasus was triumphant.
Kahn and his lone crewmate, Mark “Crusty” Christensen, shattered the transpacific double-handed record with a time of 7 days, 19 hours, 38 minutes and 35 seconds.
The previous record-setters had taken more than 10 days to make the trip in 2001.
So how did Kahn do it, with a partially crippled boat, no less?
By being singularly obsessed with optimization — finding the right crew and the right technology to survive and prosper on the high seas.

 One of the original prototypes for a sleep and motion tracker that Kahn used on his Transpac races. Talia Herman/Wired

By day, 61-year-old Kahn is the CEO of Fullpower Technologies, which builds the motion-sensing technology inside personal trackers like Jawbone Up and Nike FuelBand.
Sailing permeates life at the company, where about a fifth of the staff — including an Olympic competitor — has a background in the sport.
“The ocean lifestyle is my meditation, where I find myself,” says Kahn.

He tries to get on the water for a couple of hours each day, immersing himself in a marine sanctuary he shares with sea otters and whales.
Kahn recruited Christensen, an engineer and decorated offshore sailor, after the 2009 Transpac, and they regularly take a break from the office in the middle of the day to catch the wind at its freshest.
The overlap between worlds goes further: Kahn considers his sailing machines perfect test beds for the sensors that are his livelihood.
To be self-sufficient on the water for seven days or more, every system must be robustly built and perfectly tuned.
Kahn rattles them off: gyroscopes. Electronic flux-gate compasses. Humidity sensors. Pressure sensors. And, of course, satellite navigation.

To make those systems function at the highest level, Kahn doesn’t settle for off-the-shelf components.
In his 2009 bid, Kahn and Christensen worked to modify a system that measures wind direction.
Typically, the constant pitching and rolling of the boat throws off those measurements.
But by using sensors to detect that motion and correct for it, they could get crucially enhanced information about wind conditions.
“We were trying to monitor the sailboat, trying to help us keep it upright and optimized,” says Kahn, “and it turned out that sailing became an incredible practical laboratory.”

Their true secret weapon, however, may have been sleep tracking.
When sailing double-handed, Kahn explains, “there are times when neither one of us can sleep.
We’ll sleep maybe 45 minutes in 24 hours.”
So Kahn started experimenting with biosensors, creating prototype sleep monitors that he wore and tested on his Transpac bids a decade before personal trackers came into prominence.
His prototype appears to have the sophistication of a Tamagotchi: a single white button, a bulky square face of translucent blue plastic that reveals the vibrator and circuit board inside, and a worn navy blue Velcro strap for a wristband.
But underneath the plastic, it has the same functionality as a Jawbone Up, with a three-axis linear accelerometer to keep track of micromovements.
With this roughshod design, Kahn and Christensen figured out how to take 26-minute power naps optimized for each of them, taking turns at the helm while the other slept.
“Part of our success has been because of our ability to manage sleep better than other people,” Kahn says.
Kahn hopes to find a new yacht worthy of the Transpac — above all, he considers that record-setting trip something to be proud of.
But his ambitions of another high-stakes ocean crossing have ebbed at the moment in favor of mastering a different kind of high-performing sailing machine.

 "The ocean lifestyle is my meditation, where I find myself."

His current target: The Nacra F20 carbon, a 20-foot catamaran with hulls designed by Morelli & Melvin, the team that worked on the America’s Cup AC72.
The cat is a feat of engineering and design, a beautiful boat with two sculpted hulls that look as if they could cut butter.
The Nacra features the curved daggerboards rapidly becoming a mainstay of cat sailing.
They increase the boat’s stability, prevent it from getting knocked away from the wind, and provide some lift, allowing the boat to ride higher and encounter less resistance from waves.

 Kahn stands next to a beached catamaran; its two rudders with winglets at the base are visible.

The gate to Kahn’s right opens up into the harbor’s parking lot, so it’s just a quick roll down to the boat ramp to get it into the water.

  Talia Herman/Wired

But as with the equipment aboard his Transpac yacht, Kahn isn’t satisfied with the best of the best.
So he started ripping the Nacra apart.
In his Santa Cruz shop, Kahn’s team has created new daggerboards, replacing the so-called C-foils with L-foils that angle inward to provide controlled lift to the hulls.
They’re the same basic design as those in the AC72.
Without foils, a boat’s speed is limited by the drag of the hulls.
“But once you get the foils out on a cat,” says Kahn, “there’s nothing but a little bit of drag that keeps you from going faster and faster and faster” — up to 30 knots at its fastest so far.
Kahn’s boat is one of the first of its size to try foiling like this.
At Kahn’s home on the docks — built there for easy access to the harbor’s boat ramp — he shows off the foils as Pegasus sits beached on his driveway.
They’re thin, tapered fins with a gently curving S-shape.
At the Pegasus workshop, filled with dripping resin and flying fiberglass, Kahn’s team shapes them by layering sheets of carbon into wooden molds.

That shape has remained largely unchanged, but there’s one more crucial element: the elevator, the bottom to the foil’s “L” that provides that crucial lift.
It attaches to the fin separately, allowing the team to make minute changes that could make all the difference in the boat’s foiling hydrodynamics.

Kahn got his first taste of the water on the coast of France, where he began windsurfing as a 14-year-old.
To see him sailing on his heavily modded cat with Christensen is to see that teenage adrenaline junkie sparring with the wind.
Almost as soon as the boat leaves the harbor, Kahn is off the boat, feet straddling the side of the hull as his body dangles off the edge.
He’s held in place by a trapeze attached to his body harness.
A long tiller extension allows him to steer a sailboat that he technically isn’t even on.
Pointing to the winglets placed perpendicular to the boat’s two normal rudders (another source of lift, along with the foils), Kahn describes his beast as “more like an airplane than a sailboat.”
But that comparison is most apt when the boat gets going in the 12-knot breeze off the coast of Santa Cruz.
Every time the boat hits 11 knots or so, the cat’s stiff, lightweight carbon body rises above the waves, revealing a glimmer of sunlight between the water and the base of the hulls.

The wind isn’t quite as strong as the boat would like it, and ocean swells break over its twin bows, driving the boat back into the water almost as soon as it starts to rise.
But those brief moments, the hulls hovering weightlessly over the water, are mesmerizing.
“I can’t say how cool it is,” says Kahn.
“The feeling is really that of flying.”
The boat’s clearly still in experimental mode.
As Christensen and Kahn leap over the waves, sea water sloshes through roughly hewn holes where the daggerboards pierce the hulls.
Ideally, those holes will be plugged, eliminating the drag from the water inside.
But “that’s the last half of a percent of performance,” says Kahn — and the boat still has plenty of optimization ahead.
Every day it seems a new improvement is made.
After its last race, through California from Richmond to Stockton, the team decided to slightly modify the bearings that orient the foil in its place, allowing for an extra degree or two of range that lets them better tailor the lift to the conditions they’re sailing in.
Right now, the daggerboards are hoisted into place by hand.
Eventually, they’ll have a line attached to more easily put them in place.
Over time, those small refinements will hopefully help team Pegasus dominate in its races like it did in the Transpac.
This week, though, it’s taking on a smaller challenge: Competing for the first time in the casual Wednesday night races out of Santa Cruz Harbor.

Sizing up their competition at the docks, it doesn’t seem quite fair to put this racing machine up against old-school monohulls, dragging their heavy lead keels like a ball and chain.
But Kahn’s in it for the love of sailing, not for the trophies.
The compromise? “We’ll just try to do two laps for every one of theirs.”

Links :

• LinkedIn : An Introduction to Understanding Sleep

How Eratosthenes calculated the Earth's circumference

In the mid-20th century we began launching satellites into space that would help us determine the exact circumference of the Earth: 40,030 km.
But over 2000 years earlier, a man in Ancient Greece came up with nearly the exact same figure using just a stick and his brain.

Vendee Globe seen by satellites

 The Vendée Globe is the only solo, non-stop, without assistance sailboat race around the world. Nicknamed “Everest of seas”, only 71 sailors under 138 managed to reach the fish line since its creation. This figure is showing how difficult this worldwide event is, in which sailors are facing extreme cold, huge waves and threatening sky across the great south.
Extremes conditions involve exceptional means.
The race department asks CLS, Collecte Localisation Satellite, a CNES subsidiary, to watch this modern times adventurer from space.
Read more on : race.cls.fr

Iceberg detection

To detect the presence of icebergs and predict their direction, CLS has developed a solution used to:

•  Detect iceberg populations produced by glaciers in the Antarctic using radar satellite observation data
• Define risk zones
• Model the direction of icebergs and their melt-rate according to currents and surface temperatures, wind levels and the shape and size of the iceberg
• Readjust the direction model using observation data from radar satellites in the Subantartic zone (around 50° South).
• Perform (using these radar images) a correct display of icebergs of a significant size (>50m).

 see Threatening icebergs detected from space

CLS is thus able to provide race organisers with maps of the Antarctic, with the location of iceberg populations and predictions concerning their drift direction