Auroras affect sat-nav systems due to unknown mechanism 

Posted: March 15, 2017 by oldbrew in solar system dynamics, Uncertainty
Tags:

Alaskan aurora [image credit: NASA]


When they say ‘an as yet unknown driver is causing the problem’ they probably don’t mean a motorist 😉

The leading hypothesis used to explain why the aurora borealis and its southern hemisphere counterpart, the aurora australis, play havoc with global positioning systems has been knocked into a cocked hat, reports Sott.net.

The spectacular auroras are produced when gas particles in the earth’s atmosphere collide with charged particles emitted by the sun. The resulting plasma turbulence has long been assumed to be the reason that the phenomena interfere with Global Navigation Satellite Systems (GNSS).

Now, research led by Biagio Forte of the Department of Electronic and Electrical Engineering at the University of Bath in the UK has discovered that the predicted turbulence doesn’t actually exist, meaning that an as yet unknown driver is causing the problem.

To conduct the research Forte’s team collaborated with the European Incoherent Scatter Scientific Association (EISCAT), setting up in northern Norway to observe and analyse the aurora borealis using radar and a GNSS receiver.

As the radar team developed visual imagery of the phenomenon, the GNSS team looked at how it interacted with global positioning systems. The results ruled out plasma turbulence. Instead, the team write in the Journal of Geophysical Research Space Physics, the interference is caused by a “new instability mechanism”, as yet unknown.

Although the Bath researchers work generated far more questions than answers, the study is important because it shifts focus in what is rapidly becoming a critically important field. Global positioning data is already widely used in personal mobile phones, car navigation systems and aircraft, but the imminent roll-out of autonomous vehicles, as well as developments in remote-warfare, mean it will soon be ubiquitous.

“The potential impact of inaccurate GNSS signals could be severe,” said Forte. “Whilst outages in mobile phones may not be life threatening, unreliability in satellite navigations systems in autonomous vehicles or drones delivering payloads could result in serious harm to both humans and the environment.”

Source: Auroras affect sat-nav systems due to unknown mechanism — Science & Technology — Sott.net

Comments
  1. oldbrew says:

    From: SPACE WEATHER PREDICTION CENTER
    NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

    Space Weather Message Code: ALTEF3
    Serial Number: 2564
    Issue Time: 2017 Mar 14 0500 UTC

    CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
    Continuation of Serial Number: 2563
    Begin Time: 2017 Mar 02 0440 UTC
    Yesterday Maximum 2MeV Flux: 3433 pfu

    NOAA Space Weather Scale descriptions can be found at
    http://www.swpc.noaa.gov/noaa-scales-explanation

    Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems. [bold added]

    http://www.swpc.noaa.gov/products/alerts-watches-and-warnings

  2. alanpoirier says:

    It’s an electric universe.

  3. gymnosperm says:

    ” European Incoherent Scatter Scientific Association (EISCAT)”

    Reluctant as I am to wax sarcastic about an important scientific post, the name of this association is just too rich in irony to pass up.

    My bad. I’m sure these folks know quite a lot more about the incoherent scatter of ionized particles produced by the electrically neutral solar income than I do.

    As usual, the take home message is we all still have a lot to learn.

  4. oldmanK says:

    Is it effecting civilian aircraft navigation???

  5. Tim Hammond says:

    All the best science leads to more questions than answers. It means we are opening up areas to study and getting below the surface.

  6. oldbrew says:

    oldmanK: not sure if or how aircraft GPS might be affected, but aircraft don’t fly directly over the poles anyway – a practice related to the older compass-based systems.

    This looks quite informative…

    –Irregularities in Earth’s upper atmosphere can distort GPS signals
    –Scientists are studying these irregularities to help overcome their effects on communications

    http://www.jpl.nasa.gov/news/news.php?feature=4493

  7. RoswellJohn says:

    Aurora isn’t just over the poles. It in a circular band around the magnetic poles. And commercial aircraft DO fly over those regions every day. But they also have other navigation methods like inertial navigation.

  8. oldbrew says:

    Eruptions on the sun trigger surprising phenomenon near Earth
    Date: March 17, 2017
    Source: Technical University of Denmark (DTU)

    Summary:
    Eruptions on the Sun’s surface not only send bursts of energetic particles into the Earth’s atmosphere causing disturbances in our planet’s magnetic field, they can also strangely decrease the number of free electrons over large areas in the polar region of the ionosphere, new research concludes. [bold added]

    http://www.sciencedaily.com/releases/2017/03/170317132043.htm

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