LightSquared: Man-Made Solar Flares?

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.

How will your investment in high-accuracy positioning be compromised, and what can you do to protect it?

Brent Jones

About Brent Jones

Brent Jones, PE and PLS, is Esri's land records/cadastre industry manager. He spearheads worldwide surveying and cadastre practices for Esri and has more than 20 years experience in executive-level technology planning and market development in the engineering, surveying, and geospatial industries.
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  1. Marc Cheves says:

    The magazine been covering this since January. Our latest posting can be found here: The article not only explains the situation, it also provides numerous talking points for using with your elected officials. Coming up (at least in Seattle) on Sep 22 is a local rally organized by Gavin Schrock. For information on how to create a rally where you live, please contact

  2. The absolute worst thing we can do as members of the surveying profession is to think the interference by LightSquared on high precision GPS won’t happen. I have listened to several presentations by LightSquared and they are in this to WIN!!! We can’t rely on anyone else to protect us without our commitment to educate them on the realities of a ground based network and its without question interference on the equipment we use everyday. The threat is real and the “spinning” of facts by LightSquared is becoming more intense by the day. I guess a 4 BILLION dollar current investment with a planned future 14 Billion dollar investment will do that.

  3. Anthony Vannozzi says:

    I concur with John. This is very very real. The President is scrambling to “create jobs” to get re-elected. Lightsquared projects something like 15,000 jobs, funded with private dollars. The President has also gone on record indicating that wireless broadband access is part of his social agenda to provide highspeed internet in rural and areas underserved by fiber-optic cable. There is no question that high precision GPS could become a casualty of mutually exclusive policy agendas if we don’t continue to fight hard. Anyone who watched the House Committee on Space, Science and Technology hearing last week saw this policy clash quite clearly. I have had the opportunity in the last few weeks to experiment with GPS on a Real Time Network (RTN) as part of my GIS parcel mapping research. RTN is an AMAZING technology for society and each time I am out I can’t help but think how it will evaporate if lightsquared’s full court press gets traction.

  4. ED OBRIEN says:

    The thing that worries me the most about LightSquared is that it has become a Political Football. I watched part of the hearing last week and was struck when one of the committee members opened the door by stating that the Government was complicit in its role by allowing LightSquared to get as far as it has.

    It is said that Politics is like making sausage, you don’t want to see laws / and policies being made. Because this issue is so politically charged it stands the chance of moving forward. This issue will not be defeated on scientific merits alone. The fact that the GPS signal is analogous to a teaspoon of water whereas the proposed LightSquared signal is compared to Niagara Falls is not lost on the layman legislator. There is a turf-war being fought over the Electromagnetic Spectrum LightSquared understood when they “purchased” real estate in this portion of the Spectrum that there were Zoning restrictions, this band is meant for Space to Earth communication ONLY.

    Land surveyors know firsthand the benefits of GPS positioning technology. GPS can cut days off of a project and strengthen the accuracy framework. The reliance on GPS technology has become Standard Operating Procedure (SOP) and the equipment is not cheap.

    The June 2011 report entitled: “The Economic Benefits of Commercial GPS Use in the U.S. and the Cost of Potential Disruption” by Nam D. Pham, Ph.D. states: “…the direct economic benefits of GPS technology on commercial GPS users are estimated to be over $67.6 Billion per year in the United States”; and that “…there are more than 3.3 million jobs that rely on GPS technology, including 130,000 jobs in GPS manufacturing industries and 3.2 million in the downstream commercial GPS-intensive industries.

    The GPS Technical Working Group (TWG) test results were found to be not favorable for LightSquared . So, LightSquared spins off in a new direction with a new plan to use the lower portion of the Spectrum, which was not adequately made part of the TWG testing. LightSquared states that they will only impact “high end users” a small percentage of the total GPS users (they are making it a numbers game). Land surveyors fall into this group that would need to retro-fit filters that have not been invented yet or buy new equipment. FCC FILE:

    Couple the above numbers with the Department of Defense (DOD) concerns and the threats to the Homeland Security and it would seem like a no brainer that this issue should have been tossed out in the first round. It is ultimately a public safety issue. Surveyors need to write their Senators and Congressman asking them to weigh-in on this Political Football and to bring whatever influence they may have to the forefront of this turf-war.
    Edward J. OBrien, P.L.S.
    RISPLS President
    NSPS Governor Rhode Island
    EMail: EJOBPLS2000@COX.NET
    CELL: (401) 533-0883
    RISPLS is now on Face Book

  5. Brent Jones says:

    General Shelton of the Air Force testified today in front of the Armed Services Committee on the impact that the disruption of GPS on national security (

    If you have an interest in GPS, it’s worth your time to watch the hearing (

  6. I don’t consider myself a “fear-monger” as LightSquared’s Jeff Carlisle referred to me during the Survey Summit discussion panel. I spent four years in the active duty military and 14 years at a high-tech start-up. If I was the panicky type, I’d be six feet under by now.

    If you want a quick backgrounder on the LightSquared issue, you can view a free webinar I conducted in late June on the subject. It’s focused on the high-precision GPS/GNSS user.

    You can also listen a recording of my discussion on ACSM’s Radio Hour that was broadcast August 8, 2011.

    This week was a bad one for LightSquared, but also a bad one for GPS users.

    On Monday, LightSquared VP Martin Harriman boldy stated that the FCC would make a decision within a month and that “Sprint wouldn’t sign this big deal if it didn’t expect it to be resolved”.

    Does this guy think people are stupid? For $9 billion, I would sign it too if I was Sprint. There’s not downside for Sprint.

    Of course, Harriman was wrong. On Tuesday, the FCC announced it needs more testing before it can make a decision. Clearly, that will take months, many months.

    On Wednesday, LightSquared lawyer Jeff Carlisle claimed they fixed the GPS interference problem and that the fix could be in production in “several months”.

    He’s crazy. If his solution works and is acceptable to the GPS industry (which I doubt), it would take several months just to test all the different receiver solutions.
    Think about all the high-performance GPS handhelds on the market (Trimble GeoXT/XH, Ashtech ProMarks/Mobile Mapper, etc.). Are they really going to suggest a LightSquared “clip-on” accessory for those handheld units? Seriously? How about replacing antennas on CORS? New antennas would need to be characterized by NGS. All of this in “several months”? This doesn’t even consider production ramp-up, testing, etc.

    I don’t believe they have a reasonable solution. This clearly shows they are in panic mode and will say whatever they need to keep things moving.

    I’ve been pretty open-minded about LightSquared proposing a solution, but this really insults our intelligence. But as we’ve seen previously with LightSquared, it’s not about finding a practical solution for the GPS user community; it’s all about selling a solution to the FCC. The problem is that the FCC doesn’t have to live with half-baked “solution”, we do.

    Next week is going to be interesting. LightSquared is sending their Chief Network Officer to the ION GNSS conference in Portland to sit on the “Can LightSquared and GPS Co-Exist” panel discussion. The panel members are some of the highest-level GNSS engineers in the world. it will be interesting. I’ll be there and will be Twittering (GPSGIS_Eric) and writing about what I see/hear.

    The issues I’ve written about previously are still relevant:

    1. LightSquared/FCC did not give the GPS user community sufficient notice. We didn’t know about it any earlier than last November. The precedent set previously shows that ~12 years is needed for the GPS user community to transition to new equipment without financial hardship.

    2. Even with LightSquared using only the lower spectrum (1526-1536Mhz), it still interferes with $2+ billion dollars worth of high-precision GPS receivers. Who’s going to pay that bill? The GPS user community that was given no advanced notice?

    They can argue all they want about who’s fault it is, new filter technology, DoD standards, etc., but at the end of the day, obsoleting 200,000+ expensive high-precision GPS receivers valued at $2+ billion dollars would be devastating to American small businesses and Fed/State/Local gov’t.

    3. LightSquared sells high-precision satellite data communications services to the high-precision GPS industry (via OmniSTART). Before LightSquared was formed in 2010, its predecessors (Skyterra, MSV) sold the same services to the GPS industry for many, many years. In the course of business over many, many years, LightSquared and its predecessors have encouraged GPS receiver manufacturers to design receivers that look into the MSS band (1525-1559MHz) in order to access LightSquareds satellite data communication services. This service has generated tens of millions of dollars in revenue for LightSquared and its predecessors over many years and continues to be a revenue source for LightSquared today.

    4. LightSquared mobile devices (uplink band 1626.5-1660.5MHz) potentially have a devastating impact on GPS and GNSS receivers. I’m afraid this is being lost in all the discussion about the downlink band. The uplink band could have a worse affect on GPS and GNSS receivers than the downlink band.

    LightSquared mobile devices are potentially portable GPS/GNSS jammers. The FCC needs to seriously investigate the interference impact of LightSquared mobile devices (1626.5-1660.5Mhz) on GPS receivers. It is already known that Inmarsat (1626.5-1660.5MHz) devices and Iridium (1616-1626.5MHz) devices interfere with each other, but Iridium devices are only used in remote areas so it’s not a widespread problem. It is also known that these devices interfere with the GLONASS L1 signal (1597-1605MHz). We don’t know the extent of the effect that LightSquared mobile devices will have on GLONASS L1, GPS L1, Galileo L1, or Compass L1 signals. The problem is that no LightSquared mobile devices are available to test. Yes, lab simulations can be performed, but LightSquared devices will be made in Asia, among other places, where the designers won’t care one bit about GPS/GLONASS interference. There is not an acceptable design margin, if any, to allow for sloppy LightSquared device designs.

    5. GLONASS wasn’t part of the live testing. According to more than one TWG member I spoke to, there was not enough time to test GLONASS.

    6. Galileo, Compass and GPS L1C all use wider L1 bandwidth than the current GPS L1 C/A. These future signals are at risk.

    There are a myriad of technical issues that are beyond what LightSquared and the FCC can or will understand.

    As I’ve said before, I’m not saying “no” to LightSquared, I’m saying “no” at this time. It takes time and due diligence to find a solution, if one exists. Their actions this week demonstrate they aren’t committed to either one.

    Eric Gakstatter
    GPS World magazine
    GeoSpatial Solutions
    Mobile: 541/829-3443

  7. Donny Sosa says:

    The technology LightSquared offers is important and we can all appreciate the jobs, new markets, and public services this technology will bring—but it should not come at the cost of High Accuracy GPS.

    Until further studies are performed and verified, we should be cautious of how this technology makes it to prime time. Several experts have weighed in on the issue above offering links to more information to quench your search. Rather than echoing their statements, I want to bring up something we’ve been working on with ACSM, NSPS, NGS, and others in the survey and mapping communities—GPS Day. Let’s teach the world the importance of location and prevent a similar issue from happening again.

    If the public knew more about GPS, I feel these discussions would have much more popularity and carry the concerns it deserves. GPS Day is a movement to build awareness of land surveying and the technologies that overlap and support surveying. This event is dedicated to attract all users of GPS while demonstrating the capabilities of GPS measurement, once only practiced by surveyors. We need to educated the public of the importance of GPS (high accuracy or otherwise) to grow and support the survey community while protecting our national security.

    A web site is in the making for information related to GPS Day and I’ll be sure to post it once it’s complete.

    Donny Sosa
    Esri Surveying Industry Specialist