[time-nuts] GPS Jamming in the UK

[Rob Kimberley]

Brooke,

You are quite correct - SA has been done away with, but SA degraded only CA
performance. 

The new GPS technologies don't need CA either degraded or undegraded in a
time of conflict.

Fun times ahead?

Rob 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Brooke Clarke
Sent: 13 November 2007 23:06
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS Jamming in the UK

); SAEximRunCond expanded to false
Errors-To: time-nuts-bounces+rk=timing-consultants.com at febo.com RETRY

Hi Rob:

It was my understanding that SA has been legislated away (mainly to promote 
civilian GPS use) and so the military no longer has the option of turning SA
on 
to deny an enemy use of GPS.

So we are developing GPS jamming that will disrupt civilian/enemy GPS
receivers 
yet allow a crypto keyed US GPS receiver to function.  This would be done
near 
a battle zone and so would not effect the GPS system in other locations.

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Cam


Rob Kimberley wrote:
> ); SAEximRunCond expanded to false
> Errors-To: time-nuts-bounces+brooke=pacific.net at febo.com RETRY
> 
> C/A code was originally designed as course clock to allow P/Y code
hardware
> to lock on, and you should also note that latest generation P/Y hardware
can
> directly acquire and stay locked without C/A. In the event of a local or
> Global conflict, C/A will be denied to some or all users.
> 
> The jamming tests undertaken may be part of testing new generation
hardware
> in high jam/non C/A scenario.
> 
> More info in Hugo Fruehauf's excellent paper which I've put on my web
site.
> 
>
http://www.timing-consultants.com/images/Web%20Site%20App%20Notes/saasm%20co
> ml%20brfg%207-04.pdf
> 
> (and yes, I know I need to remove the spaces in the title)
> 
> Rob K
> 
> 
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of GandalfG8 at aol.com
> Sent: 13 November 2007 16:51
> To: time-nuts at febo.com
> Subject: [time-nuts] GPS Jamming in the UK
> 
> ); SAEximRunCond expanded to false
> Errors-To: time-nuts-bounces+rk=timing-consultants.com at febo.com RETRY
> 
>  
> I've not come across this before and when a friend first  fowarded the
link 
> from another group I thought it was a spoof, and  still only half
> convinced:-), 
> but I've just copied this from the official  Ofcom Website in the UK......

> "The Ministry of Defence conduct occasional tests on military  systems
which
> 
> may result in some loss of service to civilian users of the Global  
> Positioning System (GPS) including in-car navigation devices and networks
> which  rely on 
> GPS signals. Ofcom seeks to provide citizens and consumers with
information
> 
> about possible interruptions to these services via these email  updates
> giving 
> advanced notification of these tests. It must be emphasised that  this 
> notification process only warns of future jamming excercises that are
> brought to 
> the notice of Ofcom and may not cover all jamming exercises. It  cannot be

> assumed that any loss of service is due to jamming exercises." 
> There's an option to sign up for email notification..... 
> _http://www.ofcom.org.uk/static/subscribe/select_list.htm_ 
> (http://www.ofcom.org.uk/static/subscribe/select_list.htm)  
> Anyone come across this before or actually experienced any  identifiable 
> jamming of signals? 
> regards 
> Nigel GM8PZR
> 
> 
> 
>    
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