I'm curious whether it would need 360 degree rotation? Would simply cycling about 120 degrees on the end of a short arm be just as good and could be done without a rotary joint? I understand that now the RX is moving but within a small radius would it be unbearable? Or would 300 degrees around the axis be sufficient?
>From Tom Holmes, N8ZM > On May 7, 2015, at 11:49 AM, John Ackermann N8UR <j...@febo.com> wrote: > > Just put the GPS antenna, receiver, battery, and a low power RF transmitter > modulated by the PPS (wide bandwidth = fast edge time) on the turntable, then > use an appropriate receiver to demodulate the PPS and feed it to the rest of > the system. Put the RX antenna directly above (or below) the turntable so > the path length remains close to constant. Using FM might also remove > Doppler effects from the received pulse. > > On 5/7/2015 11:18 AM, Tom Van Baak wrote: >>>> I wonder if anybody ever made a rotating GPS antenna to average out the >>>> X-Y phase-center offset ? >> >>> Of course, this does not really work with a gps antenna, unless you >>> put the whole receiver onto the rotary table. But then you shift >>> the problem onto the PPS output (note: amplitude noise translates >>> into phase noise). >> >> Attila, >> >> My thought was to put PHK's proposed experiment entirely on the rotating >> table: antenna, receiver, local Cs standard, laptop, and battery. You could >> also get interesting data if you slightly offset the antenna from the >> center. It would make the ultimate GPS Spirograph. (for those of you under >> 40, http://en.wikipedia.org/wiki/Spirograph will explain) >> >> /tvb >> _______________________________________________ >> 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. _______________________________________________ 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.
