Sat Nav Jammers at Air Bases
in [UK Drivers]
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From: Mike P on 21 May 2010 07:28 Does anyone know if the forces use Sat Nav "jammers" around air bases and sensitive places? I was down in Burghfield yesterday. Location here http://maps.google.co.uk/maps?f=q&source=s_q&hl=en&geocode=&q=reading&sll=49.560852,1.746826&sspn=2.433568,4.938354&ie=UTF8&hq=&hnear=Reading,+Berkshire,+United+Kingdom&ll=51.405792,-1.024303&spn=0.018954,0.038581&t=h&z=15 As I was using the sat nav and still managed to take a wrong turning, I ended up on Burnthouse lane around the edges of what I think is an AWE site. Suddenly the sat nav tells me I'm doing 144mph in the middle of a field, the "you're going faster than 90mph" bell is ringing, and it just went insane, until I got back into Grazely Green. I suppose it's some sort of jamming equipment - it did the same on the way back too. Never done it before, or since. Mike P
From: loopy livernose on 21 May 2010 07:53 > Does anyone know if the forces use Sat Nav "jammers" around air bases > and sensitive places? > > I was down in Burghfield yesterday. Location here > > http://maps.google.co.uk/maps?f=q&source=s_q&hl=en&geocode=&q=reading&sll=49.560852,1.746826&sspn=2.433568,4.938354&ie=UTF8&hq=&hnear=Reading,+Berkshire,+United+Kingdom&ll=51.405792,-1.024303&spn=0.018954,0.038581&t=h&z=15 > > As I was using the sat nav and still managed to take a wrong turning, > I ended up on Burnthouse lane around the edges of what I think is an > AWE site. > > Suddenly the sat nav tells me I'm doing 144mph in the middle of a > field, the "you're going faster than 90mph" bell is ringing, and it > just went insane, until I got back into Grazely Green. > > I suppose it's some sort of jamming equipment - it did the same on the > way back too. Never done it before, or since. > > Mike P Its more likely (I am no expert though) that radar or something similar effected it? I know (when the local airfield was RAF) when the radar made a low pass (or something) it made TV's locally go "snowy" and killed the old "radio" portable telephones (something Dect fixed).. but I doubt they are deliberately jamming the sat nav, more likely their equipment is just so much more powerful? as said before.. just observations.. and I look forward to reading other peoples viewpoints on the matter.. LL
From: GT on 21 May 2010 08:17 "Mike P" <mikewpearson1(a)googlemail.com> wrote in message news:85d2f3e6-dd05-4346-9d63-12e713cdebb6(a)z17g2000vbd.googlegroups.com... > Does anyone know if the forces use Sat Nav "jammers" around air bases > and sensitive places? As I understand it, sat navs use line of sight communication with overhead satellites. So to jam one, you would need to block the sky with a large sheet of something like metal or a slate house roof! I'm fairly sure you would have noticed a giant roof over the sky! Can a vertical line of sight communication that uses light, be jammed by a horizontal transmission??
From: Halmyre on 21 May 2010 08:41 In article <4bf679cf$0$28206$c3e8da3(a)news.astraweb.com>, a(a)b.c says... > "Mike P" <mikewpearson1(a)googlemail.com> wrote in message > news:85d2f3e6-dd05-4346-9d63-12e713cdebb6(a)z17g2000vbd.googlegroups.com... > > Does anyone know if the forces use Sat Nav "jammers" around air bases > > and sensitive places? > > As I understand it, sat navs use line of sight communication with overhead > satellites. So to jam one, you would need to block the sky with a large > sheet of something like metal or a slate house roof! I'm fairly sure you > would have noticed a giant roof over the sky! > > Can a vertical line of sight communication that uses light, be jammed by a > horizontal transmission?? > > > The GPS transmissions are not coming down a tightly focussed beam (otherwise the SatNav wouldn't be able to accumulate data from several satellites). If you were to have a local transmitter pumping out power in all directions at the right wavelength it would swamp the receivers on any nearby SatNavs. In fact, this has happened elsewhere: http://www.gpsworld.com/gnss-system/signal-processing/the-hunt-rfi-776 -- Halmyre This is the most powerful sigfile in the world and will probably blow your head clean off.
From: GT on 21 May 2010 09:29
"Halmyre" <no.spam(a)this.address> wrote in message news:MPG.26608fef2337909998a356(a)news.eternal-september.org... > In article <4bf679cf$0$28206$c3e8da3(a)news.astraweb.com>, a(a)b.c says... >> "Mike P" <mikewpearson1(a)googlemail.com> wrote in message >> news:85d2f3e6-dd05-4346-9d63-12e713cdebb6(a)z17g2000vbd.googlegroups.com... >> > Does anyone know if the forces use Sat Nav "jammers" around air bases >> > and sensitive places? >> >> As I understand it, sat navs use line of sight communication with >> overhead >> satellites. So to jam one, you would need to block the sky with a large >> sheet of something like metal or a slate house roof! I'm fairly sure you >> would have noticed a giant roof over the sky! >> >> Can a vertical line of sight communication that uses light, be jammed by >> a >> horizontal transmission?? > > The GPS transmissions are not coming down a tightly focussed beam > (otherwise the SatNav > wouldn't be able to accumulate data from several satellites). If you were > to have a local > transmitter pumping out power in all directions at the right wavelength it > would swamp > the receivers on any nearby SatNavs. > > In fact, this has happened elsewhere: > > http://www.gpsworld.com/gnss-system/signal-processing/the-hunt-rfi-776 Thanks - good link. |