If the processes are all independent, then you can assume that A and B will have the lowest noise and estimate the ADEV values of C and the second nosiest oscillator with good confidence, and of the lowest noise oscillator with some confidence (keyword: "three cornered hat").

Just a sample from an unoffical NMEA0183.pdf *ZDA Time & Date – UTC, Day, Month, Year and Local Time Zone* *$--ZDA,hhmmss.ss,xx,xx,xxxx,xx,xx*hh* So for a GPS or a timing unit on a NMEA-0183 bus, do they report their best estimate of time to the nearest 10ms when the packet is sent?

Hi, All I have seen so far is an ADEV plot, and that is not a good tool to estimate such systematics in. I would like to see the phase & frequency data, it would probably be better for this type of diagnostics. Do we have the raw measurements in a readable format?

Hi There also are a lot of papers going back a ways by Jim Barnes and David Alan (sometimes together and sometimes separately) related to multiple clocks driving a single “estimate” of what time it actually is.

Using the worst case value just for a rough estimate, mid-90's would mean some devices could be 25 years old: 5ppm * 25 yrs -> 125ppm off nominal Note that nominal starts at anywhere from +/-10 to +/- 50 ppm depending on what model you have, and aging could be in the same direction as initial offset, opposite direction as initial offset, or could change direction

This LH parameter 'OSC' will give you an estimate, how close the internal OCXO is currently synchronized to GPS time, but you always have to take into account the typical ADEV jitter for your specific measurement setup. Frank

The new FDM proton precession magnetometer, using a very powerful frequency estimator, contributed to the project from the NMR spectroscopy community by a professor at U.C. Irvine, should make for a fun and challenging experiment for many experimenters and university students.

Given the condition of our feeders this evening, I estimate 6-7 lbs of thistle were eaten today. The numbers at our Barkhamsted yard feeders have averaged 175 for the past week but the flock grew again today. I don't know the final tally, but I wouldn't be surprised if it surpassed the 300- or even 400-mark.

I had nothing to measure with, but estimated that they were at least 4 inches wide, side to side. Since I've never seen bear tracks in snow I didn't know what they should look like so I took pictures as best I could of the only decent tracks. I did note that there was NO visible sign in those tracks of claws, which would rule out cougar.

However, I did hear on NEWS 12 that "experts' had seen the turtle and estimated it to have been about 150 years old. No mention of who those "experts" were, but NEWS 12 reporter said that the station would follow up to see what the cause of death was, if at all possible.