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GPS jamming
RST Engineering wrote:
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 Any given EW aircraft in the USAF fleet to narrow localize and an AWACs that'll get a skin paint on the balloon. They could probably pump enough energy through the radar to pop the balloon. |
#2
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GPS jamming
You are going to skin paint a vinyl balloon filled with helium? So I turn
it on for ten minutes and then off for ten. By that time it has drifted a few miles. Try spotting a balloon that only has to lift about five pounds at a quarter mile, much less a couple of miles. Sorry, no "probably" allowed. Neither helium nor vinyl absorb enough power to be popped by anything other than a direct hit. Jim -- "If you think you can, or think you can't, you're right." --Henry Ford Any given EW aircraft in the USAF fleet to narrow localize and an AWACs that'll get a skin paint on the balloon. They could probably pump enough energy through the radar to pop the balloon. |
#3
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GPS jamming
Gig 601XL Builder wrDOTgiaconaATsuddenlink.net wrote:
RST Engineering wrote: 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 Any given EW aircraft in the USAF fleet to narrow localize and an AWACs that'll get a skin paint on the balloon. They could probably pump enough energy through the radar to pop the balloon. Good luck in finding a radar that will give skin paint on a helium filled, plastic balloon. You could DF from the emitted signal, but a simple on/off timer on the transmitter would make it real hard to find in any real wind. -- Jim Pennino Remove .spam.sux to reply. |
#4
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GPS jamming
"RST Engineering" wrote in message
... 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. Your scenario: 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. My defense: EMP (you didn't mention cost ,feasibility, or collateral damage) Your countermeasures: ???? |
#5
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GPS jamming
Countermeasure is trying to figure out how you are going to generate an EMP
on a moving target at FL300? Nuclear explosion? One a day or one every few hours depending on how often I launch? No radar paint means that you can't detect altitude, just azimuth. Jim -- "If you think you can, or think you can't, you're right." --Henry Ford EMP (you didn't mention cost ,feasibility, or collateral damage) Your countermeasures: ???? |
#6
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GPS jamming
On Wed, 22 Aug 2007 10:19:01 -0700, Jon
wrote: On Aug 22, 7:47 am, Denny wrote: GPS has become the navigation tool of choice... The jamming of GPS is so trivial that any reasonably bright 14 year old, can manage it - and within his allowance to boot.. Some older navcoms will jam the gps in the plane when tuned to certain frequencies... A quick google search on the radio models and those certain frequencies is enough information for one to build a wide area gps jammer... It used to be the gov't worried about a terrorist using the GPS to guide a weapon to a precise point... Whereas, they should worry about a terrorist blocking GPS over a wide area on a dark and stormy night, with airliners unable to land, ships losing navigation near the coast, etc... denny 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 Except that source doens't need to be very far off the ground which severely limits the detection range for ground based systems. 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 Happy mitigating Regards, Jon |
#7
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GPS jamming
Anyway,while I use and appreciate my GPS moving map with terrain
warnings, I have not removed my NDB, ILS, VOR, DME from my panel... If push really comes to shove I can home on the local radio station from 80-100 miles out and from there fly a compass course to the airport... denny |
#8
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GPS jamming
On Aug 22, 6:14 pm, "Roger (K8RI)" wrote:
On Wed, 22 Aug 2007 10:19:01 -0700, Jon wrote: [...] 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 Except that source doens't need to be very far off the ground which severely limits the detection range for ground based systems. Fair enough. Mayflower's products are intended for airborne use. [...] Regards, Jon |
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