On Thu, Feb 9, 2012 at 1:08 AM, Ron Frazier (NTP) <[email protected]> wrote: > OK, so I'm replying to my own message, what's strange about that? 8-) > > VERY preliminary data, after running an hour with my USB GPS without PPS > outputting only GPZDA sentences, I'm getting ~ +/- 5ms peak offsets of the > computer clock vs GPS. I'm liking it so far. It initially looks more > stable than when I was using GPGGA sentences.
Warning: This is addictive. After you get some improvement then you try for more and so on and so on. Before your most recent change you were about three orders of magnitude from the state of the art so you have room for a great number of those "and so on and so on" cycles. Before long you'll take seriously the old joke that a man with a watch knows what time it is, but a man with two watches is never sure of the time. So you end up with three or five GPS systems and a couple rubidium standards as well. Then you'll be measuring cables to account for propagation delays and placing your equipment in temperature controlled enclosures,..... The spiral does not have an end. Now your emails have many uses of "ms" but later we will be reading "us" and even later "ns" and "ps" This is the normal progression for most addicts. Chris Albertson Redondo Beach, California _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
