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It's pretty easy to block a gps unit, although I can't imagine why
anyone would want to do that.
Here's how!
The document referenced below talks about two carrier frequencies, L1
and L2.
Carrier frequency L1 = 1575.42 MHz
Carrier frequency L2 = 1227.6 MHz.
If you were to transmit a low-intensity carrier with some sort of
modulated tone on those two frequencies (well short of half a watt --
don't want to get taken by the men in fatigues!) any GPS receiver in
the area of your transmission will not be able to "hear" the data bursts
from the gps satellites.
1) Get yourself a ham radio license (and learn about the amateur radio
code of conduct -- this sort of stuff should NOT be done to another
person without their consent)
2) Pick up a 1200mhz HT that can be modified (most can be modified to
have a pretty far transmit band) OR, find plans on the internet and
build a transmitter yourself!
3) find something to modulate the carrier (i.e., a microphone -- don't
play music or you'll be fined by the FCC)
4) Leave the sucker on, or turn it on when you're wanting to block GPS.
Voila, blocked GPS.
Again, I dont know why anyone would WANT to block GPS, as it's about the
coolest damn technology of the 20th century.
Also, doing this is probably very illegal, and if someone reports you,
the FCC and the government will track you down (trust me on this one,
we've seen hams in our area get tracked down for malicious interference)
They can do it very easily, they've got tracking technology 100x better
than what local hams have, only because they have a lot bigger budget
than us!
So, the final answer is -- if you have money ($200-500+) for the
project, are not afraid of being fined and/or arrested and put in front
of a military court for blocking our soldier's ability to know where
they are.. yes, you can block GPS.
Ref:
http://www.madsci.org/posts/archives/apr2000/955855630.Eg.r.html
Michael Maskalans wrote:
|
|
| On Jan 10, 2004, at 17:13, bob wrote:
|
|> Is there a such thing as a GPS Blocker? Or Detector?
|>
| erm.... GPS is always there. it's satellite signals - basically
| timecodes and identifiers. GPS units are just smart receivers that do
| lots of math.
| --
| Michael Maskalans <http://mike.tepidcola.com/>
| ClassTech Consultant - ITS Printer Tech - ITS Lab Tech
| mobile.612.618.4652 campus.585.274.2246 fax.360.364.3930
|
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