On 17/01/14 19:17, Dennis Ferguson wrote:
On 17 Jan, 2014, at 11:43 , Michael Perrett <mkperr...@gmail.com> wrote:
Magnus, I believe that he is referencing the the new L2 C/A code, which is
not protected. Reference
http://www.gps.gov/systems/gps/modernization/civilsignals/
It would be nice to have a receiver for that when they turn it on, but I
don't think that's what he wants. The observables used for PPP processing
are L1 and L2 carrier phase. You don't need a receiver capable of decoding
the P(Y) code but you do need a receiver capable of receiving the full
bandwidth of its carrier on both L1 and L2 and tracking the phase.
The commercial receivers which do this seem to cost dearly.
The receivers out there use the fact that the known P-code is encrypted
with a W-code into the Y-code using XOR. Over the years have various
degrees of advanced methods provided means to measure L1 C/A-code phase,
L1 P(Y) code phase, L1 carrier phase, L2 P(Y) code phase and L2 carrier
phase. Some of the earlier receivers only provided a sub-set.
Commercial receivers maintain a high price because they see a less
price-sensitive market.
Cheers,
Magnus
_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
