Thread: GPS jamming
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Old August 22nd 07, 08:31 PM posted to rec.aviation.piloting
RST Engineering
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Posts: 1,147
Default GPS jamming

Detecting it is one thing, stopping it is quite another kettle of fish.

So tell you what, I'll give you a scenario, you give me your countermeasures
and I'll defend against it.

CW emitter using a watt of erp semi-isotropic radiation inside of a "static
proof" bag (fairly decent radar stealth shielding at the frequency in
question) in a plastic bucket under a helium weather balloon. Power source
(inside the bag) is a small garden tractor 20 amp-hour battery. A watt of
RF requires about 2 watts of dc power, or about 170 mA from the 12 volt
battery. That's roughly 120 hours (5 days) of operation on a continuously
moving target. Do a little winds aloft calculation when filling your
balloon and you can drift them across the country, doing a wide area
blankout for days at a time.

Perhaps $1000 in parts at the outside and at that price I can launch one a
day for what terrorists spend as chump change. Launch point can move 500
miles via automobile in a day easily.

Jim

--
"If you think you can, or think you can't, you're right."
--Henry Ford


"Jon" wrote in message
ups.com...



They should but they probably aren't as much as some might think they
should be, given the ability to mitigate against it. The old measures/
counter-measures game.

The cool thing about a jammer, is that it has to emit something. A
single source for wide-area jamming is fairly easy to detect. There's
a company just north of here in Boston (Mayflower, used to be in
Billerica, moved down the road to Burlington) that's got a design with
phased arrays of antennae that are used to DF on the source, quite
effectively.

http://www.mayflowercom.com/products.html