On Tue, 24 Feb 2004, Don Gould wrote: > Have many people on list played with this stuff?
GPS & NMEA, yes, in the good old days of serial ports, though. The Garmin I had would automatically emit a set of NMEA records, containing position, time, and other stuff, once every second. Now, while the internal clock accuracy of a GPS - once it has locked onto the time of the satellites - must be somewhere in the order of only a few hundred ns, or better, the externally available accuracy depends on some other factors, e.g. latencies inside the GPS (including firmware!), plus respective delays in whatever gear is receiving the information. I would assume it to be questionable whether these delays, if predictable and repeatable at all, have been taken into account for the creation of the time information in the NMEA data... The extra pulse mentioned by Volker would be nice, but how does it get from the GPS to the PC? I don't mean to be smart, I just would like to know... With the old Garmin I had, connecting over the serial port, there was no such thing IIRC. Kind regards, Helmut. +----------------+ | Helmut Walle | | [EMAIL PROTECTED] | | 03 - 388 39 54 | +----------------+
