shrug-l: GPS - Accuracy Considerations

[Sykes, John]

I have been following the LightSquared issue closely for the past few months.  LightSquared is developing a broadbrand system for smart phones, I-Pads, etc.  The issue is, basically, that the bandwidth that the FCC sold to LightSquared is immediately adjacent to the GPS L-Band.  Since the LightSquared terrestrial stations are planned to be high-powered (at least compared to the GPS satellites at 11,500 miles distance), it completely blocks out the L-band GPS signal to civilian receivers (military receivers have anti-jamming features built-in).  Several federal agencies say these plans cannot go forward, as is, including DoD, FAA, NOAA, USCG, etc.  Also, several congressmen and senators have co-signed a letter to the FCC stating that GPS is vital to National Security and the LightSquared system cannot go forward as planned.

LightSquared had claimed that they had a solution to the GPS problem but recent tests indicated that this did not work.  My feeling is that LightSquared will not be OK'd to go forward with the proposed system until either; 1) a definite fix to the GPS issue is developed or 2) the FCC assigns a different bandwidth to the LightSquared system that does not interfere with the GPS system.

If you subscribe to the CORS newsletter online, it has almost weekly articles describing the LightSquared issue and progress towards resolving it.

-- John





The Department of Environmental Protection values your feedback as a customer. DEP Secretary Herschel T. Vinyard Jr. is committed to continuously assessing and improving the level and quality of services provided to you. Please take a few minutes to comment on the quality of service you received. Copy the url below to a web browser to complete the DEP survey: http://survey.dep.state.fl.us/?refemail=John.Sykes@dep.state.fl.us Thank you in advance for completing the survey.

From: shrug-l-bounces at lists.dep.state.fl.us [mailto:shrug-l-bounces at lists.dep.state.fl.us] On Behalf Of C. Henry Depew
Sent: Sunday, June 19, 2011 1:59 PM
To: shrug-L at lists.dep.state.fl.us
Subject: shrug-l: GPS - Accuracy Considerations

Greetings!
     There is a very interesting article on GPS problems in the July,
2011 issue of "Power & MotorYacht" (of all places" starting on page
34.  The impact of LightSquared broadcasts on GPS receivers may be of
interest to you as well as the general discussion of different GPS
coordinates from different GPS receivers.

C. Henry Depew
sisu26 at nettally.com

_______________________________________________
SHRUG-L mailing list
SHRUG-L at lists.dep.state.fl.us
http://lists.dep.state.fl.us/mailman/listinfo/shrug-l