Will The Solar Eclipse Disrupt GPS Signals?

Will The Solar Eclipse Disrupt GPS Signals?

Will The Solar Eclipse Disrupt GPS Signals?

(Last updated 14 August, 2017)

A few days ago on Facebook I promised a post on the subject.  Since then I’ve been following news on the “Eclipse To Come” and the possible effects on GPS service and I’ve found quite a few “scare” headlines and sensationalist headline writers at work.

Bottom Line on the Solar Eclipse and GPS

(since many of you have no time to read)

There is going to be little to no effect across the USA on GPS signals and service come August 21st.  So opines Mr. GPS.

The Problem (or the Making a Mountain From A Molehill Issue)

On Monday, 21 August US time the first visible sign of the moon’s shadow crossing over the sun will begin at Lincoln Beach, Oregon at 9:05 a.m. PDT. Totality begins there at 10:16 a.m. PDT.

Over the next hour and a half, it will cross through Oregon, Idaho, Wyoming, Montana, Nebraska, Iowa, Kansas, Missouri, Illinois, Kentucky, Tennessee, Georgia, and North and South Carolina.  The total eclipse will end near Charleston, South Carolina at 2:48 p.m. EDT.  From there the lunar shadow leaves the United States at 4:09 EDT.

If you’ve never seen a solar eclipse I highly recommend you make time for this one, there won’t be another total eclipse visible from the USA until 2025.

There Are Always “Chicken Littles”

Will The Solar Eclipse Disrupt GPS Signals?Even though eclipses of both the sun and the moon are well-known, well-studied naturally occurring events, since the science of astronomyy began there have always been dooms-dayer’s and various levels of pundits and soothsayers predicting dire outcomes during and following the events.

Lately the GPS seems to have become a popular source for “rumor mill” sensationalist stories.  I guess that’s because so many people now use GPS in some form and yet the average user, and certainly the news media, have never bothered to understand what GPS really is.

Here’s a sample article to give the flavor of what I’m talking about:

Experts: Solar Eclipse Could Interfere With Your GPS

… “I don’t want people to panic, no one is going to drive off a bridge because the GPS tells them to take a turn that isn’t there,” said Dr. Greg Earle at Virginia Tech.

Earle says the eclipse will affect the electrified portion of our atmosphere.

Translation: When your phone asks the satellite orbiting the earth for directions — there may be some interference.

“They’ll be a little error associated with GPS signals at that time,” said Earle.

It will likely mean slightly less responsive guidance, if you notice anything at all. And it’s far less of a problem for you than it is for say, NASA….



The “sensationalist” part of this story is mainly the headline.  If you read the remarks from the expert quoted in the article, Dr’ Earle, his remarks are hardly sensational at all.

There will actually be little or no effect noticeable to any GPS users.  Mr. GPS agrees.

So why doesn’t the article headline read something like “Experts Agree Eclipse Will Have No real Affect ON GPS”?  After all, that’s the gist of what the article is saying.

Sensationalism Sells Is The Only Explanation I Have

Here’s a well-written article from NASA which was crafted to answer questions GPS users might have, rather than trying to sell newspapers or drive visitors to a website.

NASA describes expected impact of total eclipse on GPS

….There is a region of Earth’s upper atmosphere, called the ionosphere which affects radio waves, including GPS.

The ionosphere consists of “ions,” a shell of electrons and electrically charged atoms and molecules. Because ions are created through sunlight interacting with the atoms and molecules in the very thin upper atmosphere, the density (thickness and consistency) of the ionosphere varies from day to night.

The ionosphere bends radio signals, similar to the way water will bend light signals. That is why you can hear AM radio broadcasts from far away at night. Also, ham radio operators rely on the ionosphere to bounce their signals from their station to the far reaches of the globe.

Since GPS is a radio signal, its measurements are slightly impacted by ionosphere changes, resulting in small increases in position error. For all except very precise GPS users, these changes are negligible.

Note that a total eclipse of the Sun is similar to our day-night cycle, only much faster. So, while the ionosphere will be more dynamic during an eclipse, it will not cause a loss of the GPS signal.

In summary, while any effects from the eclipse are of scientific interest, GPS service should not be adversely affected by the Aug. 21 solar eclipse.

Read complete article here: NASA describes expected impact of total eclipse on GPS

Thanks, NASA, we needed that.

A significant “take away” from the article is this .. to the atmosphere, especially the Ionosphere, which is critical to the accuracy of GPS signals, the effect of the solar eclipse will be virtually the same to the effect of the sun setting every night and rising the following morning.

So unless you’re afraid the GPS system is going to “take a dump” this evening, when the sun sets, I suggest there is nothing to worry about.

What do you think?  Will The Solar Eclipse Disrupt GPS Signals?