Washington, April 05: Researchers have found that solar radio bursts can have a serious impact on the Global Positioning System (GPS) and other communication technologies that use radio waves. Solar radio bursts begin with a solar flare that injects high-energy electrons into the solar upper atmosphere. Radio waves are produced which then propagate to the Earth and cover a broad frequency range. The radio waves act as noise over these frequencies including those used by GPS and other navigational systems, which can degrade a signal. Forecasters from National Oceanographic and Atmospheric Administration’s (NOAA's) Space Environment Center in Boulder, Colorado, observed two powerful solar flares on December 5 and 6, 2006. These violent eruptions originated from a large sunspot cluster identified by NOAA. On December 6, 2006, a solar flare created an unprecedented intense solar radio burst causing large numbers of receivers to stop tracking the GPS signal. Paul Kintner, Ph.D., professor of electrical and computer engineering at Cornell University, said that in “December, the effect on GPS receivers were found to be more profound and wide spread than expected”. Cornell University scientists used specially designed receivers built as sensitive space weather monitors to make the first quantitative measurements of the effect of earlier solar radio bursts on GPS receivers. Extrapolations from a previous moderate event led to the prediction that larger solar radio bursts, expected during solar maximum, would disturb GPS receiver operation for some users. “Now we are concerned more severe consequences will occur during the next solar maximum,” said Prof. Kintner. “This solar radio burst occurred during the solar minimum, yet produced as much as 10 times more radio noise than the previous record,” added Dale Gary, Ph.D., chair and professor of the physics department at New Jersey Institute of Technology. “Measurements with NJIT's solar radiotelescope confirmed, at its peak, the burst produced 20,000 times more radio emission than the entire rest of the Sun. This was enough to swamp GPS receivers over the entire sunlit side of Earth,” he said. According to NASA and NOAA researchers, the solar disturbance badly affected the Global GPS Network, which is a set of precise GPS receivers used for a variety of scientific and real-time applications. These applications include a very high accuracy positioning service that can provide a user's position with 10 to 20 cm accuracy anywhere in the world, on land, in the air or in Earth's orbit. “NASA wants to better understand this solar phenomenon so we can limit the adverse impacts on real-time systems,” said Tony Mannucci, Ph.D., principal technical staff and supervisor, Ionospheric and Atmospheric Remote Sensing Group at the NASA Jet Propulsion Laboratory. Researchers at Boston College further found the December 6 radio burst was also detected on the civil air navigation system, the Wide Area Augmentation System (WAAS). “Although our findings indicate the effects of this solar burst were less intense on WAAS than on other operational systems, mainly due to the robust system design, it is important for us to consider the potential impact of future, more powerful, solar radio bursts during periods of high solar activity,” said Patricia Doherty, co-director and senior scientist, Institute for Scientific Research at Boston College. “Space weather cuts across many different federal agencies and is a particularly fruitful area in which to develop sustained partnerships between government agencies and academia. We are, and will continue, to work together to keep the public ahead of nature's storms,” said Brig. Gen. David. L. Johnson, USAF (Ret.), director of NOAA’s, National Weather Service. The findings were presented here Wednesday at the first Space Weather Enterprise Forum – an assembly of academic, government and private sector scientists focused on examining the Earth's ever-increasing vulnerability to space weather impacts.
Reuters.com
WASHINGTON (Reuters) - A solar eruption in December disrupted the Global Positioning System, a satellite-based navigational system used widely by the military, scientists and civilians, researchers reported on Wednesday. The solar flare created radio bursts that traveled to the Earth, covering a broad frequency range, the researchers said, affecting GPS and other navigational systems. Solar flares have been known to knock out satellites and even electricity grids, but the researchers told the Space Weather Enterprise Forum this was an unexpectedly serious new effect. "In December, we found the effect on GPS receivers were more profound and widespread than we expected," said Paul Kintner, a professor of electrical and computer engineering at Cornell University in New York. "Now we are concerned more severe consequences will occur during the next solar maximum," Kintner said in a statement. Dale Gary of the New Jersey Institute of Technology said the burst created 10 times more radio noise than the previous record. "Measurements with NJIT's solar radiotelescope confirmed, at its peak, the burst produced 20,000 times more radio emission than the entire rest of the Sun. This was enough to swamp GPS receivers over the entire sunlit side of Earth," Gary said in a statement. Forecasters from the National Oceanic and Atmospheric Administration observed two powerful solar flares on December 5 and 6, 2006, emanating from a large cluster of sunspots. A giant radio burst followed, causing large numbers of receivers to stop tracking the GPS signal. "NASA wants to better understand this solar phenomenon so we can limit the adverse impacts on real-time systems," said Tony Mannucci of the U.S. space agency's Jet Propulsion Laboratory. Anthea Coster of the Massachusetts Institute of Technology said the findings showed solar radio bursts can have global and instantaneous effects. "The size and timing of this burst were completely unexpected and the largest ever detected. We do not know how often we can expect solar radio bursts of this size or even larger," she said.
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