If a GPS signal is lost to a car it might cause some confusion or an unplanned detour, but if it is lost to an aircraft it could be a life-or-death situation. Engineers at Ohio University have developed new technology called the GPS Anomalous Event Monitor to help track and record GPS signal interruptions to find out why and how often they are occurring.
The U.S. government says signals work about 99.99 percent of the time per hour, but interruptions are actually fairly common, making the technology he helped to develop necessary, said Sanjeev Gunawardena, senior research engineer with the OU Avionics Engineering Center.
The government promises GPS is reliable. We need to be sure that promise is valid
said Zhen Zhu, senior research engineer with the OU Avionics Engineering Center.
Global Positioning System signals can be interrupted for many different reasons, including satellite malfunctions, weather, enemy interference or interference from other aircraft, Gunawardena said.
You can see the entire picture of what the signal looks like Gunawardena said.
Signal interruption is not usually a problem unless the signals are being used for safety of life maneuvers, such as landing an aircraft.
You can land aircraft with GPS but do you have integrity? Is it reliable enough that you can depend your life on it? Gunawardena said.
In a worst-case scenario, the loss of a signal could result in a crash, Zhu said.
Most major airports do not use GPS technology to land airplanes. Usually airports use an older technology called Instrument Landing System, which uses radio waves and antennas, Zhu said.
The Federal Aviation Administration wants to further develop GPS technology to be used in landing and flying aircraft because it is cheaper than the ILS, Zhu said. GPS is not commonly used now because of the chances for signal interruption, he added.
The technology also has military applications because it can help alert the military if an enemy has jammed GPS signals, Gunawardena said.
GPS is being used in a lot of places we would never have imagined 10 years ago
Zhu said.
By recording interruptions and their causes, the technology can also help forecast future GPS performance. For example, researchers might be able to predict when the GPS system will be less reliable because of weather, Zhu said.
The GPS technology developed by the team at OU is being used at Memphis International Airport in Memphis, Tenn.; the FAA William J. Hughes Technical Center in Atlantic City, N.J., and at the Albany, Ohio, airport.
The research has been funded mostly by the FAA and the Office of Naval Research.
OU has been developing this software for the past six years. Three faculty members, three research engineers and numerous students have worked on the research. The research started about 15 years ago, and technology is still being further developed.
The original version of this article incorrectly stated that GPS technology developed at Ohio University was used at an airport in Albany, New York. The airport is in Albany, Ohio. The Post regrets the error.
1
News
Jackie Best
27383b.jpg
The equipment could help forecast future GPS performance.
(Photo by Sara C. Tobias/Chief Photographer)
