When you don't know how to get to where you are going, chances are you pull out a smartphone or other type of device with a Global Positioning System (GPS) to help guide you where you need to go. What you may not know is that the signals traveling between the GPS satellites and your devices can get distorted thanks to the Earth's upper atmosphere.
Researchers at NASA's Jet Propulsion Laboratory, in collaboration with the University of New Brunswick in Canada, are studying irregularities in the planet's ionosphere, a part of the atmosphere approximately 217 miles above the ground that defines the boundary between Earth and space, which could be the cause of the distortions of your GPS device.
The new study, published in the journal Geophysical Research Letters, compares turbulence in the auroral region to that of higher altitudes in order to gain insight that could help reduce the effects of disturbances in the ionosphere.
"We want to explore the near-Earth plasma and find out how big plasma irregularities need to be to interfere with navigation signals broadcast by GPS," JPL researcher and lead author of the study, Esayas Shume says.
"One of the key findings is that there are different kinds of irregularities in the auroral zone compared to the polar cap," says Anthony Mannucci, supervisor of the ionospheric and atmospheric remote sensing group at JPL. "We found that the effects on radio signals will be different in these two locations."
If you think of the ionosphere as a fluid, the irregularities comprise lower density bubbles in the area of high-density ionization areas. This creates clumps of more and less intense ionization that can interfere with radio signals including those from GPS systems and aircraft, especially at higher altitudes.
To examine the irregularities, researchers used data from the Canadian Space Agency satellite Cascade Smallsat and Ionospheric Polar Explorer. The data itself comes from one of the instruments onboard the satellite that looks at GPS signals as they skim the ionosphere.
"It's the first time this kind of imaging has been done from space," says Attila Komjathy, JPL principal investigator and co-author of the study. "No one has observed these dimensional scales of the ionosphere before."
The research has numerous applications such as improved instrument reliance on aircraft flying over the North Pole and it can even help scientists develop methods to reduce radio telescope distortion so researchers can take better measurements for astronomy. It will even help your GPS to work better and more accurately in a wider variety of locations.
"By understanding the magnitude of the interference, spacecraft navigators can subtract the distortion from the ionosphere to get more accurate spacecraft locations," Mannucci says.
