Re: [time-nuts] GPS Jammer
It is not that hard to transmit broad band noise over the entire GPS channel and clobber it entirely. Didier Sent from my Droid Razr 4G LTE wireless tracker. -Original Message- From: johncr...@aol.com To: time-nuts@febo.com Sent: Tue, 02 Oct 2012 9:33 PM Subject: Re: [time-nuts] GPS Jammer In considering the effect of a simple jammer on a GPS receiver, a simple link analysis is insufficient. What must also be considered is the anti-jam capability of the receiver which due to spread spectrum processing gain will reject any simple jamming signal even though is it 10's of dB stronger than the desired signal. 73 -john k6iql ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
One of fine units from Hong Kong delivered +32dBm of wide-band FM noise centered on 1575MHz!!! Just a tad more range than 10m I would expect. -Brian, WA1ZMS (sent from my over-priced iPad3) On Oct 3, 2012, at 8:44 AM, shali...@gmail.com wrote: It is not that hard to transmit broad band noise over the entire GPS channel and clobber it entirely. Didier Sent from my Droid Razr 4G LTE wireless tracker. -Original Message- From: johncr...@aol.com To: time-nuts@febo.com Sent: Tue, 02 Oct 2012 9:33 PM Subject: Re: [time-nuts] GPS Jammer In considering the effect of a simple jammer on a GPS receiver, a simple link analysis is insufficient. What must also be considered is the anti-jam capability of the receiver which due to spread spectrum processing gain will reject any simple jamming signal even though is it 10's of dB stronger than the desired signal. 73 -john k6iql ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
On Tue, Oct 2, 2012 at 9:40 PM, Ron Ward n6idl...@comcast.net wrote: Hi: Other than a terrorist, who would want to jam GPS? A delivery truck driver. His boss installs a GPS tracker on the truck and the driver wants to take a three hour lunch break. This is a pretty common scenario and likely the way most GPS jammers are used. I'd call it self jamming where you jam your own receiver so other people will not know where you are. Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
Some 20 to 25 years ago a law enforcement agency in California was experimenting with GPS in its patrol cars. It required that the officer press key to report his/her location. It also had a pinging capability that the officers didn't know about. Through pinging, it was discovered that a number of the officers an interesting habit. Towards the end of their shift, their cars would be found stationary off the street in industrial areas. While they were close enough to their assigned patrol routes to quickly respond to calls, they avoided coming upon situations they would have to handle that might involve a lot of paperwork or otherwise might hold them past the end of shift. They also used the time to finish accumulated paperwork. I imagine that they would have liked a GPS jammer after they figured out that they were being watched. FWBRAY Sent from my CP/M machine. On Oct 2, 2012, at 21:40, Ron Ward n6idl...@comcast.net wrote: Hi: Other than a terrorist, who would want to jam GPS? Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: Tuesday, October 02, 2012 2:28 PM To: time-nuts@febo.com Subject: Re: [time-nuts] GPS Jammer On 10/02/2012 11:05 PM, John Lofgren wrote: The 0.5 W and + 10 dBm numbers in the specs don't work out. +10 dBm is 10 mW. I suspect that the 1/2 watt is really the DC input power. Now, that makes sense. And, I'd agree about the range. +10 dBm into a dipole at 10 meters gets you about -44 dBm at the receiver antenna in a free-space model. That's really loud compared to the nominal -130 to -140 dBm you'd hear from the satellites. Indeed. Even for 10 mW it was not reasonable. No wonders that 1-10 m jammers cause such grief to DHS. Serious overkill. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
Let me just say that that's flea power! I saw some 80watt jammers being sold for movie theaters and churches. There is some very black market items from China, via Hong Kong and can arrive at your doorstep in just 4 days via DHL! What's out there would scare you. Been dealing with the fall out from such items in my day job. -Brian On Oct 2, 2012, at 4:43 PM, J. Forster j...@quikus.com wrote: Take a look at the specs of this unit: http://www.mobilephonejammer.com.au/covert-gps-jammer-portable-p-119.html The Power Output is 0.5 Watts and it claims a jamming range of 1-10 Meters. Anybody think there is something wrong? -John ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
Who would want to jam GPS? Haven't heard this one: Fishing party boat captain - knows where to find the fishing spots after years of experience. Rotates use of the spots so as not to over-fish them. Arrives at his spots to find fishermen who had gone out with him and captured the GPS locations of his spots. Now tells his customers that any GPS receivers found will be float tested by throwing them overboard. Bill Hawkins -Original Message- From: Chris Albertson Sent: Wednesday, October 03, 2012 9:27 AM On Tue, Oct 2, 2012 at 9:40 PM, Ron Ward n6idl...@comcast.net wrote: Hi: Other than a terrorist, who would want to jam GPS? A delivery truck driver. His boss installs a GPS tracker on the truck and the driver wants to take a three hour lunch break. This is a pretty common scenario and likely the way most GPS jammers are used. I'd call it self jamming where you jam your own receiver so other people will not know where you are. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GPS Jammer
Take a look at the specs of this unit: http://www.mobilephonejammer.com.au/covert-gps-jammer-portable-p-119.html The Power Output is 0.5 Watts and it claims a jamming range of 1-10 Meters. Anybody think there is something wrong? -John ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
It also says output power +10 dBm. 3 hour Li battery life. Only for legal use :) Much does not make sense with this. Forward a copy to the commission? Regards - Original Message - From: J. Forster j...@quikus.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, October 02, 2012 4:43 PM Subject: [time-nuts] GPS Jammer Take a look at the specs of this unit: http://www.mobilephonejammer.com.au/covert-gps-jammer-portable-p-119.html The Power Output is 0.5 Watts and it claims a jamming range of 1-10 Meters. Anybody think there is something wrong? -John ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
On 10/02/2012 10:43 PM, J. Forster wrote: Take a look at the specs of this unit: http://www.mobilephonejammer.com.au/covert-gps-jammer-portable-p-119.html The Power Output is 0.5 Watts and it claims a jamming range of 1-10 Meters. Anybody think there is something wrong? For a 500 mW jammer your jamming range should be much better. That's wrong. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
The 0.5 W and + 10 dBm numbers in the specs don't work out. +10 dBm is 10 mW. I suspect that the 1/2 watt is really the DC input power. And, I'd agree about the range. +10 dBm into a dipole at 10 meters gets you about -44 dBm at the receiver antenna in a free-space model. That's really loud compared to the nominal -130 to -140 dBm you'd hear from the satellites. -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: Tuesday, October 02, 2012 4:02 PM To: time-nuts@febo.com Subject: Re: [time-nuts] GPS Jammer On 10/02/2012 10:43 PM, J. Forster wrote: Take a look at the specs of this unit: http://www.mobilephonejammer.com.au/covert-gps-jammer-portable-p-119.html The Power Output is 0.5 Watts and it claims a jamming range of 1-10 Meters. Anybody think there is something wrong? For a 500 mW jammer your jamming range should be much better. That's wrong. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
On Tue, 02 Oct 2012 23:01:45 +0200, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 10/02/2012 10:43 PM, J. Forster wrote: Take a look at the specs of this unit: http://www.mobilephonejammer.com.au/covert-gps-jammer-portable-p-119.html The Power Output is 0.5 Watts and it claims a jamming range of 1-10 Meters. Anybody think there is something wrong? For a 500 mW jammer your jamming range should be much better. That's wrong. Cheers, Magnus That is what I was thinking but I am too lazy to work out the math right now and I do not have a 1.5GHz source for testing at the moment anyway. A lot depends on antenna geometry since the jammer may need to be concealed and is unlikely to be in the high gain portion of the receiver's antenna pattern. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
On 10/02/2012 11:05 PM, John Lofgren wrote: The 0.5 W and + 10 dBm numbers in the specs don't work out. +10 dBm is 10 mW. I suspect that the 1/2 watt is really the DC input power. Now, that makes sense. And, I'd agree about the range. +10 dBm into a dipole at 10 meters gets you about -44 dBm at the receiver antenna in a free-space model. That's really loud compared to the nominal -130 to -140 dBm you'd hear from the satellites. Indeed. Even for 10 mW it was not reasonable. No wonders that 1-10 m jammers cause such grief to DHS. Serious overkill. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
The Power Output is 0.5 Watts and it claims a jamming range of 1-10 Meters. Anybody think there is something wrong? I'd expect a much greater range with a 0.5 W jammer. But note that 0.5 W is the total output power -- the transmit power is only 10 dBm (0.01 W). Whatever those terms mean. (Does total output power include far IR and heat?) Note that The item is for Legal Use only! Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
HI At least from here, the link no longer works. Bob On Oct 2, 2012, at 7:48 PM, Charles P. Steinmetz charles_steinm...@lavabit.com wrote: The Power Output is 0.5 Watts and it claims a jamming range of 1-10 Meters. Anybody think there is something wrong? I'd expect a much greater range with a 0.5 W jammer. But note that 0.5 W is the total output power -- the transmit power is only 10 dBm (0.01 W). Whatever those terms mean. (Does total output power include far IR and heat?) Note that The item is for Legal Use only! Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
On 10/2/12 4:48 PM, Charles P. Steinmetz wrote: The Power Output is 0.5 Watts and it claims a jamming range of 1-10 Meters. Anybody think there is something wrong? I'd expect a much greater range with a 0.5 W jammer. But note that 0.5 W is the total output power -- the transmit power is only 10 dBm (0.01 W). Whatever those terms mean. (Does total output power include far IR and heat?) maybe it has some real bright LEDs to indicate it's on? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
In considering the effect of a simple jammer on a GPS receiver, a simple link analysis is insufficient. What must also be considered is the anti-jam capability of the receiver which due to spread spectrum processing gain will reject any simple jamming signal even though is it 10's of dB stronger than the desired signal. 73 -john k6iql ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
On 10/2/12 7:33 PM, johncr...@aol.com wrote: In considering the effect of a simple jammer on a GPS receiver, a simple link analysis is insufficient. What must also be considered is the anti-jam capability of the receiver which due to spread spectrum processing gain will reject any simple jamming signal even though is it 10's of dB stronger than the desired signal. not most simple GPS receivers which have very little AJ capability. They have a single bit quantizer (or maybe a 1.5 or 2 bit) after the LNA. If the LNA doesn't saturate, then the quantizer is captured by the strong CW carrier. This is a classic problem with DSSS receivers and led to a lot of research in the 80s on things like adaptive excisers to remove CW carriers. If you built a linear receiver with a lot of dynamic range, then, yes, the process gain will suppress the CW tone, but you still have to acquire the code, and as Dixon says (paraphrasing) acquisition is the secret sauce in spread spectrum systems. Back when I was doing this kind of thing seriously (mid to late 80s), acquisition, particularly robust techniques, were literally SECRET (in the DoD sense). There have been a nice series of articles in GPS World over the past few months about the variety of inexpensive GPS jammers out there. (and the problems they cause). ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
We don't know that they modulate the jamming signal some what. I bet 10 mW would do a good bit of harm to GPS systems even a block away. - Original Message - From: Jim Lux jim...@earthlink.net To: time-nuts@febo.com Sent: Tuesday, October 02, 2012 10:45 PM Subject: Re: [time-nuts] GPS Jammer On 10/2/12 7:33 PM, johncr...@aol.com wrote: In considering the effect of a simple jammer on a GPS receiver, a simple link analysis is insufficient. What must also be considered is the anti-jam capability of the receiver which due to spread spectrum processing gain will reject any simple jamming signal even though is it 10's of dB stronger than the desired signal. not most simple GPS receivers which have very little AJ capability. They have a single bit quantizer (or maybe a 1.5 or 2 bit) after the LNA. If the LNA doesn't saturate, then the quantizer is captured by the strong CW carrier. This is a classic problem with DSSS receivers and led to a lot of research in the 80s on things like adaptive excisers to remove CW carriers. If you built a linear receiver with a lot of dynamic range, then, yes, the process gain will suppress the CW tone, but you still have to acquire the code, and as Dixon says (paraphrasing) acquisition is the secret sauce in spread spectrum systems. Back when I was doing this kind of thing seriously (mid to late 80s), acquisition, particularly robust techniques, were literally SECRET (in the DoD sense). There have been a nice series of articles in GPS World over the past few months about the variety of inexpensive GPS jammers out there. (and the problems they cause). ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
John, Coherent reproduction of the spread PRN standard positioning signal (SPS) signal gives ~30dB of A/J protection, the GPS signal level, as received at the GPS receiver is on the order of -160 dBW (L1-CA). If the jammer outputs half a Watt, and is anywhere nearby, the receiver will not maintain lock on the civilian code as the jammer would overwhelm the receiver front end. A commercial GPS receiver has a maximum of 20 dB power bandwidth. If the jammer is present prior to initial acquisition then the receiver would certainly never acquire lock. My experience is that the civil signal (SPS) is very easy to jam, where the precise positioning signal (PPS), using the P(Y) code adds significantly more protection. All values are round numbers and the individual receivers signal strategy can make some difference, as well as GPS aiding (especially a good clock, known position, velocity and so forth). Michael, K7HIL On Tue, Oct 2, 2012 at 7:33 PM, johncr...@aol.com wrote: In considering the effect of a simple jammer on a GPS receiver, a simple link analysis is insufficient. What must also be considered is the anti-jam capability of the receiver which due to spread spectrum processing gain will reject any simple jamming signal even though is it 10's of dB stronger than the desired signal. 73 -john k6iql __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
I talked to the GPS jamming group at Nellis a few years ago. They use broadband noise to jam GPSs. If somebody is going to the Nellis Aviation Nation coming up in November, the jammer group always has a static display. They have some Soviet jammer gear they acquired. http://www.nellis.af.mil/aviationnation/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
Hi: Other than a terrorist, who would want to jam GPS? Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: Tuesday, October 02, 2012 2:28 PM To: time-nuts@febo.com Subject: Re: [time-nuts] GPS Jammer On 10/02/2012 11:05 PM, John Lofgren wrote: The 0.5 W and + 10 dBm numbers in the specs don't work out. +10 dBm is 10 mW. I suspect that the 1/2 watt is really the DC input power. Now, that makes sense. And, I'd agree about the range. +10 dBm into a dipole at 10 meters gets you about -44 dBm at the receiver antenna in a free-space model. That's really loud compared to the nominal -130 to -140 dBm you'd hear from the satellites. Indeed. Even for 10 mW it was not reasonable. No wonders that 1-10 m jammers cause such grief to DHS. Serious overkill. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
Many folks. The paranoid tinfoil hat crowd Folks who are concerned that law enforcement has placed a GPS tracker on their car. Truckers avoiding log enforcement Truckers who want to sleep rather than drive. Ambulance drivers who want to sleep but claim to have been held up at hospital. Emergency services personnel (fire,ems,law enforcement) who want to take the company vehicle where they are not supposed to. Just a few of the many I can think of! On Oct 3, 2012, at 0:40, Ron Ward n6idl...@comcast.net wrote: Hi: Other than a terrorist, who would want to jam GPS? Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: Tuesday, October 02, 2012 2:28 PM To: time-nuts@febo.com Subject: Re: [time-nuts] GPS Jammer On 10/02/2012 11:05 PM, John Lofgren wrote: The 0.5 W and + 10 dBm numbers in the specs don't work out. +10 dBm is 10 mW. I suspect that the 1/2 watt is really the DC input power. Now, that makes sense. And, I'd agree about the range. +10 dBm into a dipole at 10 meters gets you about -44 dBm at the receiver antenna in a free-space model. That's really loud compared to the nominal -130 to -140 dBm you'd hear from the satellites. Indeed. Even for 10 mW it was not reasonable. No wonders that 1-10 m jammers cause such grief to DHS. Serious overkill. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
Other than a terrorist, who would want to jam GPS? Generic bad guys who don't want the FBI tracking them. The civil liberties types are suing the FBI to make sure the get a court document before they install GPS trackers on suspects cars. Truckers who don't want their boss to know what they are actually doing. The FAA test in NJ had troubles because of truckers using GPS jammers on the nearby NJ Turnpike. There is also jamming from broken gear, perhaps broken by (mis)design. The classic is a TV repeater on a boat that wiped out Monterrey Bay. GPS World used to have a good article on-line, but the URL I had bookmarked is now 404. Anybody got a working URL? The Hunt for RFI Unjamming a Coast Harbor James R. Clynch, Andrew A. Parker, George Badger, Wilbur R. Vincent, Paul McGill, Richard W. Adler GPS World, Jan 1, 2003 -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
Hi all: Thanks for your response to my question. I had no idea! Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray Sent: Tuesday, October 02, 2012 10:07 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] GPS Jammer Other than a terrorist, who would want to jam GPS? Generic bad guys who don't want the FBI tracking them. The civil liberties types are suing the FBI to make sure the get a court document before they install GPS trackers on suspects cars. Truckers who don't want their boss to know what they are actually doing. The FAA test in NJ had troubles because of truckers using GPS jammers on the nearby NJ Turnpike. There is also jamming from broken gear, perhaps broken by (mis)design. The classic is a TV repeater on a boat that wiped out Monterrey Bay. GPS World used to have a good article on-line, but the URL I had bookmarked is now 404. Anybody got a working URL? The Hunt for RFI Unjamming a Coast Harbor James R. Clynch, Andrew A. Parker, George Badger, Wilbur R. Vincent, Paul McGill, Richard W. Adler GPS World, Jan 1, 2003 -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
