[time-nuts] LORAN-C demise

[Magnus Danielson]

bg at lysator.liu.se wrote:
>> In message <4B130050.1050002 at rubidium.dyndns.org>, Magnus Danielson
>> writes:
>>> bg at lysator.liu.se wrote:
>>> L1, L2, L3, L4 and L5 jammers is off the shelf. Not particular
>>> efficient, not to speak of L3 and L4 being of no significant use.
>> Not to mention the fact that there is a good probability that
>> GPS and Galileo will jam each other, degrading both signals more
>> than the benefit of having twice as many birds will be able to
>> compensate for...
>>
> 
> There has been rather elaborate studies conducted on Galileo signals
> disturbing GPS and vice versa. The chosen/negotiated signals give minimal
> interference to others.

The BOC signal approach has been agreed upon.

> There has been bilateral agreements reached between all (?) future global
> GNSS-systems. I think unintentional jamming between the systems are
> unlikely.

Besides, considering similar signal strength, the VCA would not be 
significantly affected if at all while the coding gain would reduce the 
other signals. Also consider that dopplers isn't make perfect matches 
and that BOC signals and C/A does not correlate while BOC signals can 
have better coding gain.

> An unintentional mishap like the recent GPS-L5 debacle is ofcause a
> possibility.

I think they learned the hard way from that bird. Then again, it does 
one of its intended missions, preserve the L5 allocation with ITU, so 
that part of the mission is good. Javad says they can overcome the bias 
error.

Cheers,
Magnus