[time-nuts] GPS Interference Question

[Magnus Danielson]

On 30/09/11 18:06, Chris Albertson wrote:
> One sure-fire "fix" to the problem is to open up the military frequencies
>   to everyone.    GPS broadcasts on more than just the common L1 freq.
> but also on 1.2Ghz.
>
> Again, not really pratical because of the huge cost of conversion

L2C is already being roled out, but relying only on that is to early as 
only 8 birds transmitt it.

L5 is also an option in the future. Only one bird transmits it.

In a distant future it would be possible to build devices with L2C & L5 
only. They are so close in frequency that a common RF chain would not be 
too hard.

What Lightsquared may force is the development of double or tripple 
receivers. It is the next challenge for commercial GPS chip designers.

Just doing L1 C/A and L2C could shift the precision of the receivers 
significantly as it now could be doing it's own ionspheric compensation. 
Just a single L2C channel would achieve that.

L1 C/A and L2C capable receiver would provide frequency disparity but 
when not needed increase the precision.

Cheers,
Magnus