[time-nuts] Week Number Rollover: Ashtech Z12

[Ole Petter Ronningen]

PPP works on observations - i.e. pseudorange and accumulated doppler range
from the antenna to the satellites  - it does not know or care what
position the reciever thinks it is at, so that makes sense.


Ole

On Sun, Apr 7, 2019 at 8:02 PM John Ackermann N8UR <jra at febo.com> wrote:

> I got the NRCan results from the overnight run, and interestingly there
> doesn't seem to be any glitch in the carrier and phase data, despite the
> receiver's lock up of position calculation.
>
> (Interesting point -- I started the run at 0200Z on 7 April, after the
> rollover event.  At that time, the receiver was still operating
> normally.  I don't know when it froze but it wasn't right at the rollover.)
>
> On 4/7/19 10:43 AM, John Ackermann N8UR wrote:
> > I was running my newly-acquired Z12 (with 1999 firmware) overnight,
> > capturing RINEX data via Lady Heather, using Cesium reference.
> >
> > This morning Lady Heather showed the receiver still tracking satellites
> > and giving time, but the lat/long/elevation were frozen -- lat and long
> > were correct, but elevation showed -821 meters!  The receiver's own
> > display showed the same thing -- "99999" as the measurement count, GMT
> > time incrementing, unchanging lat/long/elevation, -821 meters.
> >
> > I had to do a complete reset (wipe internal memory) to get the receiver
> > working again, but now it seems to be tracking normally.
> >
> > I sent the RINEX file off to NRCan and it will be interesting to see
> > what the results look like.  If anyone is interested, the raw file is
> > available for study.
> >
> > John
>
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