Hi The way doppler is corrected on a normal GPS is by having a large body of orbital data for each sat measured by a bunch of stations and then processed into the almanac. It's not a trivial process.
Since the doppler is in the hundred Hz or so range, I'd bet the conversion oscillator was designed to a similar spec. There may also be other issues as well. You would do *much* better for far less money simply using the same data collection process to do common view GPS with normal gear. Bob On Jul 4, 2013, at 3:06 AM, Hal Murray <[email protected]> wrote: > > [email protected] said: >> 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. > > If somebody wanted to use that path for a frequency reference, they could > setup a ground station to measure the Doppler and distribute that so people > could adjust their expectations. > > I suspect measuring the Doppler is a common sanity check. > > > > -- > These are my opinions. I hate spam. > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
