TAI via GPS
martin.burnicki at meinberg.de
Tue Dec 7 09:13:01 UTC 1999
Dear Markus and others,
Markus Kuhn wrote:
> "Joseph S. Myers" wrote on 1999-12-04 12:14 UTC:
> > Do you happen to know what GPS receivers are available that provide user
> > access to TAI (or some other form of the leap second offset information
> > transmitted in GPS; ideally all the parameters from Table 2-11 (UTC
> > Parameters) of the GPS Standard Positioning Service Signal Specification
> > 2nd Edition)? This doesn't seem to be the sort of feature manufacturers
> > of GPS receivers advertise, but it's of more interest to me in a GPS
> > receiver than the route storage features that get promoted.
> I don't have much experience with current low-cost GPS receivers and
> their serial port protocols. When we played in Erlangen around with NTP,
> we had a Mainberg GPS167 time receiver, i.e. a GPS receiver that was
> especially designed for reference clock applications. And even that one
> did *not* provide TAI, or the current UTC-TAI or UTC-GPS difference.
> It's output format looked suspiciously compatible to that of other
> Meinberg DCF77 receivers, which naturally have no clue about TAI.
I'm working for Meinberg and have been involved in the development of
Initially, our GPS receivers were designed to be replacements for DCF77
receivers in cases were DCF77 could not be received, so the default
serial protocol was made compatible with our DCF77 receivers.
Of course, GPS receivers provide increased accuracy and information
which is not available from DCF77. So we have implemented a simple
binary protocol which can be used to read mostly all of the information
the receiver decodes from the satellites' navigation data. This includes
raw almanach, ephemeris, and UTC correction data, and also the current
time in raw GPS format (week number and second-of-week).
An example C source code can be made available which shows how to read
> More info on Meinberg receivers is available on
> including the full manuals.
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