Arctic Investigation Underway Into Solar Storm Sat-Nav Disruption

another random user writes "Scientists in the Arctic have launched an urgent investigation into how solar storms can disrupt sat-nav. Studies have revealed how space weather can cut the accuracy of GPS by tens of metres. Flares from the Sun interact with the upper atmosphere and can distort the signals from global positioning satellites. The project is under way at a remote observatory on a windswept mountainside in the Norwegian archipelago of Svalbard in the High Arctic. The site was chosen for its isolation from electronic pollution and for its position in relation to the Earth's magnetic field which flows from space down towards the far North."

Comments

"Tens of metres"

[Baloroth]

"Tens of metres" is not exactly very precise, and it makes rather a large difference in precision if this is 20 metres or 99 metres: the first is annoying, the second might severely impair your ability to navigate, although I'd question that a bit. I mean, line of sight usually works, and in storms when it doesn't you really shouldn't be navigating close enough to the ground or a potential collision that even 100 metres off would be a dangerous problem, so am I missing something or is not that big an issue? Annoying, yes, and I can see the issue in S&R (gets a lot colder than the -20 mentioned in TFA that close to the poles, hell it gets colder than that here sometimes), but is there any highly important usage case where it would be an extremely detrimental problem?

I'm also a bit curious why they don't just use DGPS anyways, since that exists and it seems like it would solve the problem quite nicely. Added bonus that it helps even when there isn't a solar storm, and it's even more accurate than regular GPS.

Re:"Tens of metres"

[Charliemopps]

I think that's what they're trying to figure out.

Re:"Tens of metres"

[Tastecicles]

it's the difference between landing on the runway or plowing through someone's house if you're landing on instruments.

So yeah, fairly detrimental for the five hundred passengers.

Re:"Tens of metres"

[BitterOak]

it's the difference between landing on the runway or plowing through someone's house if you're landing on instruments.

So yeah, fairly detrimental for the five hundred passengers.

I think planes mostly still use ILS rather than GPS-only for instrument landings. ILS shouldn't be affected in this way by space weather.

Re:"Tens of metres"

[ravenlord_hun]

Some modern GPWS systems actually use digitalized maps of the area, determining possible collisions not only by radar but by "looking" around the map using the GPS coordinates. Pretty sure it'd cause problems there, causing false alerts and not warning other times...

Re:"Tens of metres"

[vokyvsd]

I'm a surveyor, and I use GPS to locate points to within a few hundredths of a foot (a couple centimeters, if you will). So, I don't know if my interpretation is exactly what the article intended, but I saw "tens of meters" and immediately thought "really really bad" and didn't even consider the possibility that the range of variation in "tens of meters" would be significant...

It's interesting how our minds immediately write things off like that... In most other circumstances I think I would have went exactly where you did and asked about the precision.

Something like... if you or I heard that it would cost "several billion dollars" to buy out a particular company, we'd just go "whoa, that's a lot"... but there's a select subset of people who would perk up their ears and say "umm, how much is 'several'?"

Re:"Tens of metres"

[Tastecicles]

I didn't think of that. Of course, you'd be right - GPS isn't a replacement for ILS, it's an augmentation if anything. ILS would still be the primary signal base for instrument landing, since it uses a terminal narrowband beacon which is a: static and b: situated at the end of the runway and pointing directly outward into the glide slope. GPS would be used in situations where vision is obscured, the surrounding terrain is less than ideal (big mountains in the way for instance, or open ocean either end and to the sides of the tarmac - such as Kansai in Japan which is an amazing piece of engineering and which does in fact put up with some of the worst weather on the planet - ferocious crosswinds and downpours like you wouldn't believe, yet it just carries on functioning with nary a break) and you need a little extra help to avoid touching down on the wrong bit of terrain. Accurate GPS will tell you if you're over water, an aviator unit tells you your altitude as well I believe, in AMSL and ATL (I have seen them in sailplane cockpits), all ILS is really, when you boil it down, is an autopilot landing system based on a beacon.

Re:"Tens of metres"

[Tastecicles]

I didn't think they'd want to complicate such a simple but effective safety system by adding maps which are out of date as soon, if not before, they are loaded. GPWS already utilises inputs from altitude RADAR, barometric altitude, flap and gear sensors, IAS, ILS beacons and outer markers (and a couple other things I can't remember off the top of my head).

Re:"Tens of metres"

[Animats]

why they don't just use DGPS

Because ionospheric corrections require 1) reasonably nearby ground stations measuring them, and 2) a data link between the ground stations and the receiver. In the high arctic, you seldom have either. WAAS is US only. Sweden does have a GPS augmentation system, though, one which uses ground-based transmitters to send out correction signals.

Re:"Tens of metres"

[edibobb]

Differential GPS can reduce that error of "tens of meters" to a few inches, even in a solar storm. A ground station at known location calculates the error and transmits it to the mobile GPS receiver, which adds the error into its location calculations.

Re:"Tens of metres"

[ColdWetDog]

The new system relies on GPS ADS-B

Very cool in the Alaska brush. If GPS went out it would be like tossing Alaska general aviation back 50 years when they crashed into mountains a lot. Now we only crash into mountains on rare occasions.

Re:"Tens of metres"

[riverat1]

They use ILS at larger airports but there is also WAAS (similar to DGPS) that can be used for approaches to smaller airports without ILS systems.

Re:"Tens of metres"

[riverat1]

The company I worked for helped develop ADS-B and was heavily involved in the Capstone Program. ADS-B essentially forms a network between all airplanes and ground stations equipped to send and receive the signal. An airplane periodically (like every few seconds) broadcasts its location and vector so anyone who can receive the signal can tell where the other plane is and where it's heading in relation to it. The GPS that's a part of it also had terrain maps and will warn you if you're headed for a mountain. I'm pretty proud of the work we did on ADS-B. It's improved the safety of flying small airplanes in Alaska immensely and it's coming to the lower 48 States gradually.

Re:"Tens of metres"

[Anonymous Coward]

I'm also a bit curious why they don't just use DGPS anyways, since that exists and it seems like it would solve the problem quite nicely. Added bonus that it helps even when there isn't a solar storm, and it's even more accurate than regular GPS.

The entire arctic should be covered with a mesh of digital on the ground equviliants to cellphone towers? DGPS in the most uninhabited, remote parts of the world, its hard enough here in the arctic to get a good ISP, or even cellular service. This DGPS idea was probably not thought through that well.

Re:"Tens of metres"

[Anonymous Coward]

In theory it can, but in practice, we can't calculate the correction fast enough during serious storms. The CPOS system normally provides real-time cm-precision positioning in Norway, but it breaks down during some storms. Improving this is a subject of research. See this article for details: http://www.swsc-journal.org/articles/swsc/pdf/2012/01/swsc120026.pdf

Re:"Tens of metres"

[FireFury03]

WAAS is US only.

WAAS is specifically the US SBAS (satellite based augmentation system). There are others - europe, for example, has EGNOS, which is compatible with WAAS receivers. However, both systems broadcast from geostationary satellites, which are very low to the horizon at high latitudes so hard to receive.

I presume there is a good technical reason why they don't broadcast the SBAS signals directly from the NavStar satellites, but I don't know what it is (I would be very interested if someone who knows could explain though).

Re:"Tens of metres"

[Eyeball97]

I hate to break it to you, but aircraft don't use GPS for landing.

It's the difference between your car telling you to turn left "here" when it actually means the junction 45m up the road. Which admittedly could be an even bigger problem for the special kind of twit who already drives into walls "because the satnav told me to".

Re:"Tens of metres"

[Anonymous Coward]

When the GPS signal spec was developed, the navigation datastream did not contain capacity for corrections. The SBAS satellites broadcast the corrections using a modified packet format, which can be decided by an SBAS aware receiver. However, on a non-SBAS receiver the signals will be discarded as invalid.

Changing the primary signal format would break compatibility with old existing receivers (which are mainly military, and the raison d'etre for GPS).

The European Galileo system will explicitly transmit the correction messages from the primary satellites as part of the main message.

Re:"Tens of metres"

[ravenlord_hun]

Airplanes don't care if there is a new street or changes to the city layout, and hills/other geographical features don't tend to move around too much - so maps get outdated actually very slowly. The reason why they are doing the whole thing is late warnings. Approaching steeper hills at more significant speeds can mean that the radar only tells the pilots to pull up when it's too late. As for all the things you mentioned, only the RADAR matters as far as ground proximity goes... :)

Re:"Tens of metres"

[RaceProUK]

I'm also a bit curious why they don't just use DGPS

Because it'd be hideously expensive to get enough base stations to cover enough landmass to help sat-navs. If my company (which makes lorry fleet tracking equipment software) wanted to use DGPS, we'd have to get base stations installed throughout the UK, Switzerland, Germany, the US, and Australia.

Re:"Tens of metres"

[FlyingGuy]

GPS approaches are getting better http://www.aopa.org/flightplanning/articles/2012/120209faa-marks-gps-approach-milestone.html but still lack decent altitude information. GPS uses a stepped approach method ie: at position X,Y you need to be at Z altitude as read from the approach plate ( or indicated on the GPS device ) whereas with the more tradition ILS approach providing a glide slope, you fly a standard 3 degree slope and are guided by the signal until decision height is reached.

Re:"Tens of metres"

[FlyingGuy]

How long does it take the unit to "settle" so that the reading is stable?

Re:"Tens of metres"

[jasnw]

I've been working on ionospheric impacts on GPS damn near since GPS was launched. Comments:

1. Ten meters is indeed not a hell of a lot until you consider things like (a) your average airport runway is likely not much more than 20 meters in width, particularly in areas where there probably isn't other forms of landing assistance and GPS is needed, and (b) while ten meters horizontally can be OK, ten meters vertically can be brutally bad if you're trying to land an airplane in bad weather and are depending on GPS to tell you where you are. You either fly into the ground or "flare" for landing 10 meters too high. Not good in either case.

2. DGPS can help, but only if the ionospheric disruption is such that it throws the DGPS base station off the same amount (and direction) as the users GPS. This is not necessarily a good assumption to make, and is still being researched. The ionospheric scintillation discussed in TFA is a problem for DGPS.

3. This is mainly a problem for non-static GPS uses. Surveryors typically take a long-term GPS position measurement (at minimum several minutes) which will, if done correctly, smooth through the big errors caused by ionospheric disruptions. The main problem is dynamic uses of GPS, like on aircraft, where you can't linger around to integrate up a good position solution.

Bottom line is that GPS isn't quite the "all weather system" it was cracked up to be. Lots of time and effort has gone into trying to resolve ionospheric impacts on GPS over the past several decades. Again, typically not a problem for lots of applications, but a potentially serious problem for dynamic position/velocity GPS users.

Re:"Tens of metres"

[ColdWetDog]

As someone who flies small planes in the Alaska brush on a regular basis, I thank you and everybody else involved. It allows everybody to fly safer and once everyone else is on board, it will keep the other nemesis of Alaska bush flying - mid air collisions - from happening.

The company that flies the plane that I part own (Harris Air) was one of the first small operators to use Capstone. They love it.

Re:"Tens of metres"

[riverat1]

Cool. Too bad everybody doesn't already have it but it is expensive to get installed. Something like $20K last time I heard.

Re:"Tens of metres"

[Anonymous Coward]

I admit I don't know one GPWS from another. However, if it is used as an input to such a system, as you approach that steeper hill at a more significant speed, barometric altitude matters a great deal as far as ground proximity and timely warnings are concerned.

Comment removed

[account_deleted]

Comment removed based on user account deletion

RE:Work In Progress

[Anonymous Coward]

Good site selection.

Obvious answer.

GPS Block I were Polar Orbiting.

Since then, per DoD Theater Operations and Budget Constraints, the GPS coverage was cut-back to coverage of Mid-Lattitudes; i.e. a Donut.

However, GLONASS still has true Polar Orbit Coverage.

Recommendation.:

For Polar research ... forget GPS entirely (err shall I say this{?}: SA is still operative ... !! .... just 'zeroed out' when connivence is not an ... 'issue.')

Use GLONASS.

Your estimates of uncertainty and P-Value of the geophysical value you seek will be much better and acceptable. :)

Unanticipated consequence of global warming

[ortholattice]

Why is this urgent? Answer: "The research is pressing because rapid [Arctic] warming is attracting more vessels, tourists and mining operators."

Urgent?

[jtownatpunk.net]

I don't get why this is "urgent". It's not a new issue. It's not unknown. It's not unexpected. Seems more like a perfectly normal investigation to gather data to help better understand and compensate for a known phenomenon.

Re:Urgent?

[dubidub]

I think they main reason why this is getting attention now is the oil industry. There are large oil reserves in the Arctic and accurate positioning data is needed when drilling oil wells.

GPS to Svalbard?

[Shag]

The project is under way at a remote observatory on a windswept mountainside in the Norwegian archipelago of Svalbard in the High Arctic.

Oh, don't be silly, it's not like I'd be trying to get turn-by-turn directions to a place like that, anyway.

Re:GPS to Svalbard?

[Anonymous Coward]

Let me get out my tinfoil again. See we are talking high frequency transmitter and reciever here. Like a microwave, the better to toast your popcorn in? the better to "heat" something. Several antennas, that can "aim" the output to. Real real tinfoil. okay. Just as the one in alaska changed the weather pattern to the south of the antenna, where the polar jet was prior to the introduction, heading southerly along the mountains, this high heat input changed the pattern to the south of the field. sending the air pattern to create drought, and fewer storms, you change the heat over norway, the jet is southerly there, to a more south, over europe rather then over moscow, remember getting colder closer to moscow, saw another article a couple of days age, new record cold at south pole, verging on the precipitation of COO and sublimination of it out of the atmosphere, Come on snarkies, and warmist, what is the relationship, Starting two or so years ago, and bbc is not on the top of it, sssssssh it's public? So what did they do prior to this?..

Apple wins again

[gmuslera]

Their new maps already have the corrections for non accurate GPS data in the case of a really big solar storm, maybe of the "turning into nova" class. You just need to use them only in that event.

So this was the problem with Apple Maps?

[__aasehi2499]

They were using only the GPS satellites being affected by the solar storms. Hey exclusive walled garden is exclusive walled garden.

Try Looking At A Map

[Anonymous Coward]

Did you check to see where the Norwegian archipelago of Svalbard is in relation to mainland Norway? I thought not.

The northern most city in the world is in Norway, which is north of Alaska's most northern settlement (Barrow).

Svalbard to GPS

[andersh]

Interestingly they control satellites from Svalbard, not the other way around :)

Kongsberg Satellite Services operates both SvalSat in Norway's Arctic regions and TrollSat at the Norwegian Antarctic base on the opposite pole. It is the largest commercial ground station in the world. The first customer was NASA, which uses it for its EOS satellites, NEN and SLR. The European, Japanese and Indian Space Agencies also use it extensively. The business idea for Svalbard satellite station is to provide cost-effective services to polar satellite operators.

The SvalSat system is used for Near real-time (NRT) Maritime Situational Awareness services, including vessel detection and oil spill monitoring, and producing images on demand from Earth using data acquired by satellites in orbit. With stations near both poles and at mid-latitudes, KSAT can access satellites at many positions in orbit and download almost any conceivable mix of data from them.

NASA's Satellite Laser Ranging network (SLR) is a fundamental measurement technique used to support both national and international programs in Earth dynamics, ocean and ice surface altimetry, navigation, and positioning. SLR utilizes a global network of stations [including Svalbard] to measure distances by bouncing very short pulses of laser light off special reflectors installed on satellites orbiting the earth, and also left on the Moon by the Apollo astronauts and Soviet rovers. By accurately timing the round-trip time of flight of these pulses, distances can be computed and precise orbits determined. This data is then used to acquire fundamental information about the geophysical processes of the Earth and the Earth-Moon system.

To supply NASA, United States Department of Defense, NOAA, ESA and others with this data they even laid a dedicated submarine cable to Svalbard from mainland Norway (1400 km).

Global Seed Vault

[andersh]

I almost forgot the most interesting counter-argument to your joke! If the world experiences a major catastrophe where agriculture is severely affected it probably would be quite useful to be able to reach the Svalbard Global Seed Vault, hehe.

Try finding the seed bank without GPS and keeping an eye out for the very hungry polar bears that roam there!

HAARP anyone?

[Anonymous Coward]

Isn't that exactly what HAARP does?
http://www.haarp.alaska.edu/

great book

[Anonymous Coward]

Storms from the Sun by Michael Carlewiecsz and Ramon Lopez tells this story! Check it out.