How GPS was affected by the solar eclipse

September 15, 2017  - By

I had my special ISO-certified glasses ready. Living in Oregon, I wasn’t about to miss the once-in-a-lifetime chance to see a total eclipse of the sun.

On Aug. 21, my family drove a few miles north to get into the path of totality, which for us lasted about a minute. It was definitely worth the field trip.

Besides regular folk like me, experts in numerous fields turned their eyes — and their instruments — to the eclipse.

The National Center for Atmospheric Research took to the air with a Gulfstream V fitted out with sensors and equipment for atmospheric research. The flight gathered data about the sun that can’t be collected from the ground.

With better instruments than ever before, for the first time scientists had the chance to observe the corona in the infrared spectrum, which may provide insight into the sun’s magnetic fields.

Back on terra firma, atmospheric scientists closely monitored changes in temperature and other weather effects. The temperature dropped as much as 7 degrees in Crossville, Tennessee, reports the National Weather Service.

Scientists at zoos and aquariums across the country closely watched animal behavior during totality. Species exhibiting unusual behavior included elephants, hippos, crocodiles and penguins.

As for GPS, experts from the NASA Jet Propulsion Laboratory, NASA HQ Earth Science Division and the University of New Brunswick kept a close eye on the event, collecting data from GPS receivers and other ionospheric monitoring tools to better understand exactly how the ionosphere reacts to a total eclipse of the sun.

The scientists found a “decrease in the number of free electrons in the part of the Earth’s ionosphere along the eclipse path where sunlight was temporarily blocked by the moon…

“TEC [total electron content] time series from two continuously operating GPS monitoring stations near the path of totality…show a small dip of about 2 TECU [TEC units] or so around 18:00 UTC on Aug. 21, coincident with the timing of the eclipse.”

The eclipse also affected WAAS real-time correction data from geostationary satellites.

While study of the data continues, it’s clear that GPS easily withstood the eclipse. Learn more here.

About the Author: Tracy Cozzens

Senior Editor Tracy Cozzens joined GPS World magazine in 2006. She also is editor of GPS World’s newsletters and the sister website Geospatial Solutions. She has worked in government, for non-profits, and in corporate communications, editing a variety of publications for audiences ranging from federal government contractors to teachers.