High-accuracy GPS is at risk
Solar flares are naturally occurring explosions that occur on the sun’s surface from energy, suddenly released, that is stored in twisted magnetic fields. Solar flares produce a burst of radiation across the electromagnetic spectrum and disrupt some electromagnetic instruments on earth. The sun is currently at the peak of an 11-year cycle of solar flares. You may have noticed GPS interference while out on the job recently. Solar flares are the probable cause of this interference.
Unfortunately, solar flares aren’t the only thing that can interfere with your GPS signal. Planned interference from LightSquared, a broadband company, is on the horizon. LightSquared proposes to build 40,000 high-powered transmitters to deliver wireless 4G service to the majority of the United States. Combined with a satellite that provides Internet access, the transmitters will serve the entire country. The wireless portion of this spectrum is adjacent to one of the two frequencies that high-precision GPS units depend on. GPS is designed to receive very weak signals transmitted from orbiting satellites. The signals produced by the proposed LightSquared ground stations are over a billion times stronger than GPS receivers were designed to receive, which will cause great interference with the high-accuracy GPS tools of many trades. This interference will render GPS unreliable in many industries that rely on GPS; its broad impact will affect such industries as precision farming, aviation, construction machine control, and public works, to name a few.
If you are unfamiliar with this serious issue, you may want to watch two videos that were filmed at the inaugural Survey Summit, held in July 2011. The first is of LightSquared’s Jeff Carlisle, and the second is from Trimble’s Pete Large, who also represents the Coalition to Save Our GPS. Each gentleman does an excellent job of explaining his side’s position on the issue.
Despite independent tests demonstrating that the LightSquared network essentially destroys the ability to use high-precision GPS, the Federal Communications Commission (FCC) has given LightSquared a waiver permitting the company to continue through the permitting process. Unlike solar flares, which occur naturally and only interrupt GPS occasionally, the implementation of the man-made LightSquared network may eliminate high-accuracy GPS as we know it.
