Hi If the WAAS sats were purpose designed to provide a high accuracy carrier, then yes there are ways to do it. The fundamental design concept of a "bent pipe" is that you don't do any of that. You do not care what's going through the bird, it just maps the input frequencies to the output and amplifies them (a lot). Again, the WAAS signal is simply piggybacking on existing hardware. The conversion oscillator is not locked to the GPS carrier (or to any other carrier). It's simply a free running quartz based oscillator, running into a synthesizer to get the appropriate microwave frequency.
Bob On Jul 3, 2013, at 5:21 PM, Dennis Ferguson <dennis.c.fergu...@gmail.com> wrote: > > On 3 Jul, 2013, at 11:47 , Bob Camp <li...@rtty.us> wrote: >> The pipe in this case is up on one frequency and down on another. The >> conversion oscillator on satellite that's the weak link, no matter how good >> the signal from the ground happens to be. > > That's certainly true but it doesn't seem like a problem that the > presence of a high stability free-running oscillator, like a rubidium, > would help. The oscillator on a geostationary satellite has a > continuous frequency reference to lock to (the uplink carrier) and > hence only needs short term stability sufficient to track this and > transfer it accurately to the downlink. It seems like this is the > kind of problem that quartz excels at. > > Dennis Ferguson > > _______________________________________________ > 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.
