Friday, November 17, 2017

Can an autonomous sailboat cross the Atlantic ?

Sailing a boat across the Atlantic is challenging enough for a human sailor.
But what about a computer?
BBC Future visits a sailing regatta for robots.

From BBC by Nathan Hurst

No one has ever sailed an autonomous boat across the Atlantic.
Few have even tried – just a handful of teams have competed in the transatlantic Microtransat Challenge since it began in 2010.
All have failed, for reasons including “caught in a fishing net”, “picked up by a fishing boat” or, frequently, simply lost at sea with a vague last-known location.

The closest anyone has ever come was the summer of 2017, when a boat called Sailbuoy, built by a company called Offshore Sensing, travelled 1,500 kilometers – more than half way – before it started going in circles.

Officially, the winner of the Microtransat is the fastest team to achieve the crossing; in reality, the winner is the first.
They have set rules, like a maximum vessel length (2.4m or 8ft) and an obstacle/collision avoidance system.
But teams can just launch their boat anytime between July and December, and it doesn’t even matter what direction they go – Newfoundland to Ireland, or vice versa.
Competitors include university clubs, but also autonomous vessel companies like Offshore Sensing (a company that makes sail-powered autonomous research vessels), and even the US Naval Academy.
The main goal is just finishing, after all.

The boats had to compete in the same kind of events that would test human sailors
(Credit: Aland Sailing Robots)

“It’s just a really challenging environment,” says David Peddie, CEO of Offshore Sensing.
“You have to cope with anything the ocean can throw at you.”

Sailbuoy has a bit of an advantage.
It’s a commercial company that sells similar boats for applications in oceanography and meteorology research.
The vessel it sent on the Microtransat had previously completed several months of autonomous sailing in the rougher North Sea without any problems.

From the top, the boat looks a little like a surfboard, with a solar panel in the middle, and a short, trapezoidal sail near the front.
Aside from the sail, it sits low in the water, cutting through with a tapered nose and tail.
Rough seas toss it about, even washing over the top, without damaging it, and it seems, almost miraculously, to keep a steady course.

Others have eyes on the challenge, too, and new ideas on how to solve it.
At the Aland University of Applied Sciences, a small team of engineers has been building robotic sailboats and entering them in competitions since 2013.
This year, they bought a 2.8m (9.2ft) rigid “wing” type sail – the kind of symmetric airfoil you might see on World Cup sailboats – from a Swedish aircraft manufacturer and mounted it on their 2.4m (8ft) sailboat, ASPire.

 The calm waters of a Norwegian fjord are very different to the rough seas of the open Atlantic
Horten in the GeoGarage platform (NHS chart)

ASP stands for Autonomous Sailing Platform, and it’s white like Sailbuoy, but with a deeper, narrower hull and the tall, rectangular wing sail, flanked with two smaller airfoils.
Both rigs were built not to compete in a race, but to act as research tools, carrying water sensors to measure pH, temperature, conductivity, and salinity.
Despite the focus on research, the risks of using the new and unproven wing sail, and an untested system, Aland Sailing Robots entered its vessel in September’s World Robotic Sailing Championships, held in Horten, Norway – and won.

The World Robotic Sailing Championships is a spin-off of the Microtransat in which teams from universities or companies in related fields compete over four days in different tasks, including a fleet race, an area-scanning competition, collision avoidance, and station keeping, where the boat must hold its position for five minutes.

On a windy first day along Norway’s Oslofjord inlet, a staggered-start race saw ASPire launch shortly after a boat from Norway.
As the boats headed out into Horten’s inner harbour, a bay next to a shipyard with Sweden visible across the water, the team from Aland watched their boat slowly catch, then pass the leading boat.

Some of the robot boats will eventually try to cross the Atlantic under their own power
(Credit: Aland Sailing Robots)

“That was good to see,” says Anna Friebe, project manager for Aland Sailing Robots.
“I didn’t really think we would be able to compete.
But it ended up working, just in time.”

While the team’s strength is in software engineering and situational analysis, they still have to be adept enough at mechanical engineering to make the boat operate in the challenging seas.
ASPire was built on a hull with stabilising lead weights in the keel that was used in a paralympic sailing competition.
To this, in addition to the wing sail, the team mounted the research sensors and built a rig to winch those down into the water.


ASPire sailing at World Robotic Sailing Championships in September 2017

The boats at the World Robotic Sailing Championships vary in size and shape, from the futuristic-looking ASPire to a small, traditional two-sailed sloop that looks like the kind of remote-control sailboat a kid might sail on a pond.
On the second day of the competition, the fjord was shrouded in rain as the boats used the wind, the angle of their sails, and their rudders, to sit precisely in position without moving.
Like all the competitions, an onboard computer, programmed ahead of time, had to be capable of recognising the wind conditions, understanding its own location, and manipulating the sail and rudder to compensate.
This too, Aland won, ahead of second-place hosts University College of Southeast Norway and US Naval Academy in third place.

Day three featured area scanning, where boats had 30 minutes to cover as much of a designated area as possible.
Most used a traditional tacking manoeuvre to trace a path, playing out line to open the sail, or reeling it in to change the angle.
ASPire’s wing sail instead rotated around a central mast, which Friebe says simplified the operations.
Seen from overhead, ASPire’s path looks like a lawn-mower grid, compared to other boat’s piles of spaghetti, and so Aland made a full sweep, as day four’s collision avoidance event was cancelled due to a lack of sufficient wind.

Aland Sailing Robots was formed to compete in the Microtransat, but financial pressure – most of their funding comes from the European Regional Development Fund and goes toward the marine research platform – means they haven’t had the resources to make an attempt at the crossing.
The fun of competition and the long-term quest to cross the Atlantic are, for many of the participants, byproducts of business or research projects.


The aim of the Microtransat, according to organiser Colin Sauze, is to contribute to ocean-monitoring platforms, but also to provide a learning opportunity.

Both Aland and Offshore Sensing are focusing primarily on aquatic research.
Robots offer several big advantages over the other means of acquiring ocean data, says Peddie.
The other options – a drifting buoy, or a manned vessel – are less mobile or more expensive.
A traditional research vessel can cost $20,000 (£15,180) per day, which Peddie says could run an autonomous sailboat for several months, including the cost of the boat.
Furthermore, small boats (Sailbuoy is two metres long and weighs 60kg (200lbs)) can go places manned boats can’t, like the path of a hurricane, or volcanic or iceberg fields.

Many of the other teams, both in the Microtransat and the World Robotic Sailing Championships, are either run by industry, or partnered with industry.
The US Naval Academy team uses it as education for naval personnel (their boat, Trawler Bait, has been caught by fishermen more than once).
Half of the Chinese team is from Shanghai University, and the other half is from a company.
The Norwegian naval research institute sent an autonomous boat to help with the event.

And a lot of what they work on can be applied even beyond sailing vessels.
Autonomous shipping is already burgeoning, and the standards Microtransat competitors must meet for collision avoidance are the same ones put out by the International Maritime Organisation, and the automatic identification system that the Aland team used to transmit and receive course and speed to other vessels is the same one that commercial ships use.



“For us, as a company, it wasn’t a really big deal, the actual Microtransat,” says Peddie.
“But I’ve been following these guys for a number of years, and I think it’s an interesting concept.
It’s also something which has historic significance, like Lindbergh flew over basically the same distance connecting America to Europe.”

Still, Peddie plans to try again next year, once the Sailbuoy, which was picked up by a fishing vessel, is returned and fixed (they still don’t know quite what’s wrong with it).
“We’d just like to be the first ones who do it, and manage to cross this part of the ocean,” he says.
“Next year I expect we’ll manage the full 3,000 miles.”

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Thursday, November 16, 2017

NOAA releases final National Charting Plan

From NOAA

NOAA’s Office of Coast Survey released the National Charting Plan following a public comment period that ended in July 2017.
A draft version of the plan was released in February 2017.
The final version reflects the feedback received from professional mariners, recreational boaters, print-on-demand chart publishers, third-party data providers, software developers, and other users of NOAA charts.

The National Charting Plan is a strategy to improve NOAA nautical chart coverage, products, and distribution.
It describes the evolving state of marine navigation and nautical chart production, and outlines actions that will provide the customer with a suite of products that are more useful, up-to-date, and safer to navigate with.
It is not a plan for the maintenance of individual charts, but a strategy to improve all charts.
Much of the content of the original draft remains unchanged, but several topics were added or clarified.
These include the following:
  • Provides a more nuanced discussion of future production of raster and paper nautical charts. NOAA has no current plans to stop the production of paper or raster nautical charts. However, raster charts may look a bit different in the future.
  • Includes an acknowledgement of the role played by third-party providers of information based on NOAA raster chart products.
  • Includes an acknowledgement of the growing amount of source data that is coming from non-traditional or “crowd-source” data providers.
  • Coast survey received fewer than twenty comments regarding the possible conversion of depths from fathoms and feet to meters. These came from both recreational boaters and professional mariners. The majority of the comments favored retaining the standard U.S. units of fathoms and feet.
  • Coast survey is proceeding to make ENCs more compatible with metric units (The international product specification for ENC mandates that depths must be encoded in meters). However, raster charts will continue to show depths in fathoms and feet.
  • Coast Survey is prototyping some options that would allow users to create customized raster charts by selecting the chart size and scale, as well as the units used to display depths.
  • In partnership with the U.S. Army Corps of Engineers, Coast Survey will continue to explore ways to improve the consistent, up-to-date provision of depth information in channels maintained by the Corps. This will likely change the way channel depths are portrayed on charts.
  • Includes a section describing Coast Survey’s support to the U.S. Baseline Committee and the charting of important maritime boundaries.
You may ask a question or report a problem with any of Coast Survey’s products or services through the NOAA Nautical Inquiry and Comment System.

Canada CHS layer update in the GeoGarage platform

55 nautical raster charts updated & 3 new charts added

The mystery 'shadow zone' in the Pacific Ocean that hasn't moved in more than 1,500 years due to the unique shape of the seabed and its impact on currents

The 'shadow zone' covers an area 3,700 by 1,250 (6,000 by 2,000 km) where the North Pacific meets the Indian Ocean, between 0.6 and 1.5 miles (one and 2.5 km) below the surface

From DailyMail by Tim Collins


The 'shadow zone' covers an area 3,700 by 1,250 miles (6,000 by 2,000 km)
It is found between 0.6 and 1.5 miles (1 and 2.5 km) beneath the ocean's surface
Experts used computer modelling of ocean currents to work out how it formed
It revealed the shape of the ocean floor prevents any upward currents forming

In the North Pacific, way below the surface, hangs water that hasn't seen the sun in a millennium.
Tibor Kranjec / Eyeem

A mysterious patch of water in the Pacific Ocean hasn't touched the surface since the fall of the Roman empire.
Experts used computer modelling of deep sea currents to reveal the reason why the vast 'shadow zone' has remained near stagnant for around 1,500 years.
They found that it sits in between layers of water with currents driven by heat from the Earth below and whipped up by wind above.

The unique shape of the ocean floor means that upwards currents don’t reach high enough to push the layer upwards, leaving it in a no man’s land between the two.


A mysterious patch of water in the Pacific Ocean hasn't touch the surface since the fall of the Roman empire.
Experts found that it sits in between geothermal driven currents below and wind driven currents above

An international team of researchers, including the University of New South Wales (UNSW) and Stockholm University, studied the strange region, between 0.6 and 1.5 miles (one and 2.5 km) down.
It covers an area 3,700 by 1,250 miles (6,000 by 2,000 km), where the North Pacific meets the Indian Ocean.

Carbon dating has previously been used to identify its age and location, but scientists didn't understand what caused it to form.
By including the shape of the ocean floor in their simulation, the team was able to measure its impact on the movement of currents.
They found that water at the bottom of the ocean, heated by geothermal energy deep within the planet, was unable to rise above 1.5 miles (2.5km) below the surface.


C. de Lavergne et al./ Nature, 2017

Instead of travelling upwards, currents loop back on themselves horizontally, leaving the layer directly above untouched.
Dr Casimir de Lavergne, lead author from UNSW, said: 'Carbon-14 dating had already told us the most ancient water lied in the deep North Pacific.
'But until now we had struggled to understand why the very oldest waters huddle around the depth of 1.2 miles (2km).
'What we have found is that at around 1.2 miles (2km) below the surface of the Indian and Pacific Oceans there is a 'shadow zone' with barely any vertical movement that suspends ocean water in an area for centuries.'

While the researchers have unlocked one part of the puzzle, their results also have the potential to tell us much more.
The lack of contact with the ocean's surface means oxygenation of the zone is very low.
That means marine life is restricted, but not completely absent.

It is hoped that the research could help scientists better understand the capacity of the oceans to absorb heat trapped by rising greenhouse gases.
'When this isolated shadow zone traps millennia old ocean water it also traps nutrients and carbon,' added fellow author from Stockholm University, Dr Fabien Roquet.
'[These factors] have a direct impact on the capacity of the ocean to modify climate over centennial time scales.'

The full findings of the study were published in the journal Nature.

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Wednesday, November 15, 2017

Antarctica's warm underbelly revealed

Hotspots are located under West Antarctica; in contrast, the East is broadly relatively cold 

From BBC by Jonathan Amos

This is the best map yet produced of the warmth coming up from the rocks underneath the Antarctic ice sheet.



Measurements suggest a hot plume of mantle rock below West Antarctica.
(Helene Seroussi et al./JGR Solid Earth; Business Insider) 

This "geothermal heat flux" is key data required by scientists in order to model how the White Continent is going to react to climate change.
If the rock bed's temperature is raised, it makes it easier for the ice above to move.
And if global warming is already forcing change on the ice sheet, a higher flux could accelerate matters.

The map was made by researchers at the British Antarctic survey and is published in the journal Geophysical Research Letters.
"The heat coming from the Earth’s interior is important to understand the overall conditions that control the dynamics at the base of the ice sheet and hence the ice flow,” explained Yasmina Martos, currently affiliated to the US space agency.
"If this heat flux is elevated, the ice base can melt and produce water that acts as a sliding film.
"One result of our study is that the heat flux is higher underneath West Antarctica, where more ice is currently melting, than underneath East Antarctica.
"Even a little melting at the base helps the ice sheet to slide faster.
We also identified areas of low heat flux, which will help stabilising the ice sheet," she told BBC News.

 A map of Antarctica shows where Totten Glacier is.
Map: Chad A. Greene, University of Texas Institute for Geophysics, 2017

The West contributes most to sea level rise currently, but this is a consequence of warm ocean water eroding glacier fronts - not from the interior ice sheet being melted by underlying warm rock
No-one has actually drilled through the kilometres of ice in Antarctica to take the temperature of the bed.

Instead, the BAS team inferred the likely warmth of rocks from their magnetism.
This property can be sensed by instruments flown across the surface of the ice sheet by planes.

What happens next is a smart calculation.
Scientists know the temperature (580C) at which hot minerals lose their magnetism, so if they can gauge how close to the rock-ice interface this occurring then they have a means of estimating the heat flux.
The new map is said to represent a 30-50% improvement on previous efforts.

Surface wind causes warm water to upwell at the continental shelf break, the warm water melts Totten Ice Shelf from below, and the glacier responds by speeding up.
Chad A. Greene, University of Texas Institute for Geophysics, 2017

It supports - but with far more detail - the established idea that East and West Antarctica are very different provinces.
The East is a giant chunk of old, cold continental crust.
The West, however, underwent recent rifting in the Cretaceous (100 million years ago) that has pulled it apart.
"This rifting has thinned the crust and brought hot material from deep down in the Earth - from hundreds of km down - to within 100km or so, or even maybe less, of the rock surface," said co-author Tom Jordan.
"It confirms what you would expect from the sparse, exposed geology in West Antarctica where we have volcanoes."

One of the great advances in polar science in the past decade is the recognition that there is a really extensive hydrological network under the ice sheet.
Rivers of water feed huge subglacial lakes that fill and burst their banks periodically. Satellites see the top of the ice sheet heave and relax when this happens.

Illustration of flowing water under the Antarctic ice sheet.
Blue dots indicate lakes, lines show rivers.
Marie Byrd Land is part of the bulging "elbow" leading to the Antarctic Peninsula, left center.
Credit: NASA / NSF/Zina Deretsky

Any projections of future change in Antarctica and its contribution to sea level rise through the loss of ice have to take this basement hydrology into account, and the variations in geothermal heat flux are a critical part of the overall picture.
One research project that will see an immediate benefit from the map’s data is the quest to drill the oldest ice on the continent.
Europe, America, China and others are seeking a location where they can collect a core of frozen material that contains a record of past climate stretching back at least 1.5 million years.
This information - about historic atmospheric conditions including carbon dioxide levels - can be deciphered from tiny air bubbles trapped in the ice.

 Map of antarctic ice flow speeds (2011).

But the whole endeavour depends on the base of the ice sheet being undisturbed.
Places with a warm rock underbelly are therefore to be avoided, obviously.
"It is very exciting to see the implications this new heat map has for many communities, including new generations of ice sheet and sea level models," said Dr Martos.
"I am very glad we are contributing an important aspect at unprecedented detail. The Earth’s interior has a lot to tell us in terms on how the ice behaves."

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