"Lee Sailer" <[EMAIL PROTECTED]> writes: > 1. If everything is working, stratum 1 is better than stratum 2. > 2. If the stratum 1 hardware is suffering a slow degradation > breakdown, then the stratum 2 will be better.
Well, this is a sad (but true) commentary on the state of consumer gps firmware. The gps (x,y,z,t) calculations, if done correctly, will tell you when things are going badly. One only needs to see 4 satellites to work out the 4 unknowns. Usually one sees 8-12. There is an awful lot of redundant information in observing those extra satellites that one can use to determine error bars for the calculated x,y,z and time. There really isn't a good reason why a gps can't tell you "Hey, these numbers are out to lunch, please disregard." If the failing gps's in question put out EPE, HDOP or similar "quality of observation" numbers, it might be good to double-check that the ntp drivers really do ignore once the readings get bad. Question to the hard-core ntp jocks: Would anything break within the internal of ntp if the stratum of a reference clock were to be forcefully changed from the traditional stratum-1 for a correctly running reference to, say, stratum-5 for a gps with really crummy EPE that might be giving good time, but then again might not? (I assume this is within the spirit of "stratum" with stratum being an estimation of goodness, but please speak up if this isn't so.) I'm guessing that changing the stratum of an ntp reference clock should just work, because remote servers/peers can change their stratum and ntp automatically adapts to the new landscape. -wolfgang _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
