A lot of the changes from "bent pipe" to the new system including C-band
uplink is explained here:
http://www.insidegnss.com/node/697
While there, downlink the extended PDF version.
John WA4WDL
--------------------------------------------------
From: "Magnus Danielson" <mag...@rubidium.dyndns.org>
Sent: Saturday, July 06, 2013 12:57 PM
To: <time-nuts@febo.com>
Subject: Re: [time-nuts] Speaking of Costas loops (WAAS)
On 07/06/2013 06:29 PM, Joseph Gwinn wrote:
Code/Carrier Frequency Coherence: The lack of coherence between the
broadcast carrier phase and the code phase shall be limited. The short
term (<10sec) fractional frequency difference between the code phase
rate and the carrier frequency shall be less than 5x10-11 (one sigma).
Over the long term (<100 sec), the difference between the change in the
broadcast code phase (convert to carrier cycles) and the change in the
broadcast carrier phase shall be within one carrier cycle (one sigma).
This is interesting. Does it imply that they regenerate the code on
board?
Very unlikely, because then the bird would have to understand every
possible code, including those not invented when the bird was launched.
If it is within the Gold codes being used for GPS and WAAS, they only need
to alter the 10 bit reset-value of the G2 PRN code. See the WAAS
specification, as this method is being recommended for receivers.
Within that limit, it is relatively cheap to provide code tunability.
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.
_______________________________________________
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.
