[time-nuts] Missing GPS satellites

Bob Camp lists at rtty.us
Thu Mar 25 23:14:57 UTC 2010


Hi

I still think it's a bird on the antenna.

Bob

On Mar 25, 2010, at 7:11 PM, Magnus Danielson wrote:

> J. Forster wrote:
>> From an unnamed, but VERY credible source:
>> 
>> "> It might be that the DoD is turning the civilian signals off in combat
>>  
>>> areas to deny GPS to the Taliban and others.
>>>    
>> 
>> Quite possible.  This countermeasure was discussed more than ten years
>> ago.
>> 
>> It is possible to turn of the civilian signals -- or to leave then on
>> but _jam_ them within a selected area -- without interfering with US
>> military use of the satellites.  A modern military does not need the C/
>> A code to acquire lock on a satellite.  It can acquire the encrypted P
>> code directly."
> The preferred method of controlling the access to GPS within a region is
> GPS jammers, and the full set of efforts being spent on strengthening
> the allied forces availability to signal is to ensure ability to survive
> from jamming signal, which includes removing need for C/A locking prior
> to Y-code lock with direct lock methods, transfer of time, solutions and
> ephemeris data, and eventually means to direct additional power towards
> the area and the improved M-code.
> 
> Turning of the C/A code of a satellite will effect the 1/3 of the earth
> area that it sees, and for that to be effective in a certain area, you
> need to do that to 6-8 sats to turn it off, and that will significantly
> reduce the GPS availability for so large geographical areas that things
> they want to work will run closer to failure. So no, turning of C/A code
> is not what they want to do it. They can, but they want to avoid it.
> 
> Cheers,
> Magnus
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 




More information about the time-nuts mailing list