Featured Research

from universities, journals, and other organizations

Solar Flares Could Seriously Disrupt GPS Receivers

Date:
September 27, 2006
Source:
Cornell University
Summary:
A minor solar flare in September 2005 produced a noticeable degradation of all GPS signals on the day side of the Earth. When scaled up to the larger solar flares expected in 2011-12, Cornell researchers expect massive outages of all GPS receivers on the day side of the Earth.

Graduate student Alessandro Cerruti, left, and Professor Paul Kintner work on the antenna on the roof of Phillips Hall. They have found that the kinds of large solar flares expected in five years or so could produce massive outages of all GPS receivers on the day side of the Earth.
Credit: Photo Robert Barker / Copyright Cornell University

Strong solar flares cause Global Positioning System (GPS) receivers to fail, Cornell researchers have discovered. Because solar flares -- larger-than-normal radiation "burps" by the sun -- are generally unpredictable, such failures could be devastating for "safety-of-life" GPS operations -- such as navigating passenger jets, stabilizing floating oil rigs and locating mobile phone distress calls.

"If you're driving to the beach using your car's navigation system, you'll be OK. If you're on a commercial airplane in zero visibility weather, maybe not," said Paul Kintner Jr., professor of electrical and computer engineering at Cornell and head of Cornell's GPS Laboratory.

Alessandro Cerruti, a graduate student working for Kintner, accidentally discovered the effect on Sept. 7, 2005, while operating a GPS receiver at Arecibo Observatory in Puerto Rico, one of six Cornell Scintillation Monitor (SCINTMON) receivers. Cerruti was investigating irregularities in the plasma of the Earth's ionosphere -- a phenomenon unrelated to solar flares -- when the flare occurred, causing the receiver's signal to drop significantly.

To be sure of the effect, Cerruti obtained data from other receivers operated by the Federal Aviation Administration (FAA) and the Brazilian Air Force. He found that all the receivers had suffered exactly the same degradation at the exact time of the flare regardless of the manufacturer. Furthermore, all receivers on the sunlit side of the Earth had been affected.

Cerruti will report on the findings Sept. 28 at the Institute of Navigation Meeting in Fort Worth, Texas, where he will receive the best student paper prize. The full results of the discovery will be published in a forthcoming issue of the journal Space Weather.

The flare consisted of two events about 40 minutes apart: The first lasted 70 seconds and caused a 40 percent signal drop; the second lasted 15 minutes and caused a 50 percent drop. But this flare was moderate and short-lived; in 2011 and 2012, during the next solar maximum, flares are expected to be 10 times as intense and last much longer, causing signal drops of over 90 percent for several hours.

"Soon the FAA will require that every plane have a GPS receiver transmitting its position to air traffic controllers on the ground," warned Cerruti. "But suppose one day you are on an aircraft and a solar radio burst occurs. There's an outage, and the GPS receiver cannot produce a location. ... It's a nightmare situation. But now that we know the burst's severity, we might be able to mitigate the problem."

The only solutions, suggested Kintner, are to equip receivers with weak signal-tracking algorithms or to increase the signal power from the satellites. Unfortunately, the former requires additional compromises to receiver design, and the latter requires a new satellite design that neither exists nor is planned.

"I think the best remedy is to be aware of the problem and operate GPS systems with the knowledge that they may fail during a solar flare," Kintner said.

The team was initially confused as to why the flare had caused the signal loss. Then Kintner recalled that solar flares are accompanied by solar radio bursts. Because the bursts occur over the same frequency bands at which GPS satellites transmit, receivers can become confused, leading to a loss of signal.

Had the solar flare occurred at night in Puerto Rico or had Cerruti been operating SCINTMON only at night, he would not have made the discovery.

"We normally do observations only in the tropics and only at night because that's where and when the most intense ionospheric irregularities occur," said Kintner. However, since no one had done it before, Cerruti was looking at "mid-latitudes" (between the tropics and the poles), where weaker irregularities can occur both night and day. As a result, SCINTMON detected the solar flare.

Other authors of the forthcoming paper include D.E. Gary and L.J. Lanzerotti of the New Jersey Institute of Technology, E.R. de Paula of the Instituto Nacional de Pesquisas Espaciais and Cornell research associate Hien Vo.


Story Source:

The above story is based on materials provided by Cornell University. Note: Materials may be edited for content and length.


Cite This Page:

Cornell University. "Solar Flares Could Seriously Disrupt GPS Receivers." ScienceDaily. ScienceDaily, 27 September 2006. <www.sciencedaily.com/releases/2006/09/060927095824.htm>.
Cornell University. (2006, September 27). Solar Flares Could Seriously Disrupt GPS Receivers. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2006/09/060927095824.htm
Cornell University. "Solar Flares Could Seriously Disrupt GPS Receivers." ScienceDaily. www.sciencedaily.com/releases/2006/09/060927095824.htm (accessed September 20, 2014).

Share This



More Earth & Climate News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Climate Change Rally Held in India Ahead of UN Summit

Climate Change Rally Held in India Ahead of UN Summit

AFP (Sep. 20, 2014) Some 125 world leaders are expected to commit to action on climate change at a UN summit Tuesday called to inject momentum in struggling efforts to tackle global warming. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
New Music With Recycled Instruments at Colombia Fest

New Music With Recycled Instruments at Colombia Fest

AFP (Sep. 19, 2014) Jars, bottles, caps and even a pizza box, recovered from the trash, were the elements used by four musical groups at the "RSFEST2014 Sonorities Recycling Festival", in Colombian city of Cali. Duration: 00:49 Video provided by AFP
Powered by NewsLook.com
Raw: Wildfires in CA Burn Forest Asunder

Raw: Wildfires in CA Burn Forest Asunder

AP (Sep. 18, 2014) An out-of-control Northern California wildfire has nearly 2,800 people from their homes as it continues to grow, authorities said Thursday. Authorities said a man has been arrested on suspicion of arson for starting the fire on Saturday. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins