[email protected] said: > Then on the ground, we time tag (with an atomic clock) when the telemetry > frame is received. (giving you "Earth Received Time" or ERT) Someone on the > ground does a process of time correlation figuring out what spacecraft time > corresponds to what TAI time, allowing for the various factors like the > light time from spacecraft to the earth station.
A friend works at the VLA. http://en.wikipedia.org/wiki/Very_Large_Array They occasionally cooperate with NASA. He told me roughly the following story. NASA wanted a second opinion on the location of one of their probes out near Jupiter or Saturn or ??? No problem. They collected some data and fed it to the computers. NASA didn't like the answer. It was way off. After the appropriate amount of head scratching, the VLA geeks figured out that this was the first time that they had used that software to look at something that was within the solar system. They fixed it to do the blue-shift corrections from "nearby" rather than infinity. NASA was very happy with the revised answer. -- 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.
