On Fri, Apr 4, 2014 at 6:19 AM, Jim Lux <jim...@earthlink.net> wrote: > > Radio science and navigation measurements are quite impressive in their > accuracy and attention to detail. measuring range to cm (out of a billion > km, i.e 1 part in 1E14) and velocity to mm/s is sort of standard.
Looks to be about one order of magnitude better than standard. They claimed 90 microns/sec velocity in this case. I was looking for a document that shows the design of the radio science system in the spacecraft but did not find it. Best I can tell is they use a phase locked receiver transmitter as a kind of transponder so the high precision clock is on Earth. They say this is the first time they are able to detect mechanical movement in the ground station antenna in the Doppler data. I guess 90 uM/sec sensitivity just about everything is a noise source. > -- Chris Albertson Redondo Beach, California _______________________________________________ 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.
