http://www.youtube.com/watch?v=tZXM_g3mqew
Posted on 09/17/2011 9:10:30 PM PDT by dickmc
“GPS receivers were quite purposefully designed to operate in a portion of the radio frequency spectrum deliberately maintained as a “quiet neighborhood,” with neighboring frequencies primarily occupied by signals of comparable power levels, all based on widely accepted understanding of previous FCC rules and intent. The proposed LightSquared transmitters will produce received signal strengths five billion times stronger than the GPS received signal.”
"Some have suggested GPS equipment can be redesigned for greater filtering to mitigate the interference, but even if this is possible, we believe it would involve substantial financial cost and likely degrade the accuracy of high performance receivers, which is critical to many key GPS users."
“We believe the signal strength proposed as 'lower power' is actually the same as in the originally published LightSquared plan—and was the power level upon which the NPEF (these) tests were based....”
“Emperical test results indicate the originally planned LightSquared network does not preserve existing GPS service in representative environments for most users.”
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The pdf of this Shelton testimony is at http://www.gpsworld.com/defense/shelton-testimony-12083
The link to the related GPS World article is here.
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(Excerpt) Read more at gpsworld.com ...
ping
Looks like the test they ran showed some technical issues. So maybe the general is right?
That means GPS can be jammed. So we need a new military navigation technology anyway.
[a stupid, greedy, Chicago thuggish act with sabotage as a byproduct.]
Double plus good then!
Winston didn't need need a weatherman to see which way the Chicago wind blew that day beneath the spreading chestnut tree -- where he sold you, and he sold me...
Bfl
I fear we have become to reliant on GPS. They can be jammed, and we use them to fly and navigate.
Just think of the security implications to this story.
Unless we can come up with a solution that doesn’t involve the RF spectrum, jamming will always be a problem. The best you can do is detect jamming - you can’t mitigate or prevent it. You can, at fairly significant expense, make it more difficult to jam a network, but you can’t prevent it entirely. The premise is simple - if you’re receiving at a given frequency, all an attacker has to do is transmit continuously on that frequency. Interference does the rest and the receiver gets nothing useful.
If a tree falls in the forest and NBC, CBS, ABC, CNN, MSNBC, PBS, CNBC, the NYT, the WP, and the LAT don’t hear it, does it still make a sound?
I really don’t know what the big fuss is with GPS. Our family has never used it for navigation and we’ve always assumed that the government could shut it off on a second’s notice (as Iranian and North Korean missiles use it for navigation).
So, no direct effect on us...maybe some indirect effects, such as UPS drivers not being able to make their rounds to deliver stuff to our house, etc. But, overall, a good exercise for Americans to learn how to read a map again.
It can be heard loud and clear at the Free Republic logging camp.
My aching APRS Ping
Some of us enjoy our geocaching!!! You should try it some time!
Which is pretty far out in the woods, and only the lumberjacks are listening.
None of these scandals will amount to more than a mosquito bite until they get some traction in the LSM.
“Some of us enjoy our geocaching!!! You should try it some time!”
Sounds like fun. Of course if I did it, I’d use USGS Topographic Maps...since they accurately denote longitude and latitude.
“That means GPS can be jammed. So we need a new military navigation technology anyway.
Exactly. Why are we so damned dependent on something that can be so easily jammed (I suspect even terrorists could jam it. I know that the Norks recently jammed it for us).
Perhaps we take a step back and consider whether our dependence on GPS is healthy. For example, if GPS went away tomorrow, half of the people where I work wouldn’t even find the building.
Probably so, but if it effects Joe Publics GPS device as well should we have to scrap out our devices to enrich Obamas thugs?
http://www.youtube.com/watch?v=tZXM_g3mqew
Yes we can still read maps, but GPS is so much more convenient and easy, especially for getting around urban areas why bother unless we have to? Once you have one you get used to having it for things a map can’t do like having an instantly available approximation of how long until you will arrive, traffic, accident and weather alerts with instant re-routing and what food, hotels, attractions, parks, etc are along the road ahead. True, the government can shut it off anytime, but they haven’t and in the meantime the service has been well worth the cost of the receiver.
From “Flying” magazine:
New Report Intensifies LightSquared vs. GPS Fight
By Bethany Whitfield / Published: Jun 08, 2011
A new study presented to the FAA last week is adding fuel to the debate over the proposed expansion of broadband communications by a company called LightSquared, a plan that has drawn extensive concern from the aviation community about potential interference with GPS reception.
The study, conducted by the non-profit RTCA, confirmed what many critics have warned for months: LightSquared’s plan to make broadband transmissions on a frequency band adjacent to that used by GPS will cause significant interference with GPS reception.
After testing and reviewing the performance of four aircraft GPS receivers, members of a RTCA Special Committee concluded that, “the current LightSquared terrestrial authorization would be incompatible with the current aviation use of GPS.”
The authors of the report maintained that LightSquared’s plan would not only cause widespread disruption of GPS-based operations throughout the United States, but would completely wipe out reception in some areas. “Given the situation in the high altitude U.S. East Coast scenario, GPS-based operations will likely be unavailable over a whole region at any normal aircraft altitude,” the report said.
The study also implied that LightSquared’s plan would probably cause even greater interference with non-aviation receivers, since they lack the six-decibel safety cushion employed in receivers used for aviation purposes.
“From an aviation perspective, LightSquared upper channel operation should not be allowed,” the authors recommended. While they said certain changes could allow LightSquared’s system and GPS to co-exist, they maintained further research is necessary to determine appropriate frequency limits.
The FAA requested the RTCA study after the Federal Communications Commission (FCC) granted LightSquared a waiver to install up to 40,000 ground stations throughout the United States earlier this year. The move sparked the formation of the Coalition to Save Our GPS, as well as a letter to the FCC signed by 33 senators urging the commission to withdraw the waiver. The FCC has responded that it will allow LightSquared’s plan to move ahead only if the GPS interference issues are addressed.
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