Almanac / Lock problem

Mearns · Posted: Fri Feb 20, 2004 1:21 pm Post subject: Almanac / Lock problem

I posted a while back on the this forum that I was having satellite lock problems. Having used TTN2 since last August, I suddenly had 8 greyed out satellites but no lock during a 50 minutes drive. One of the team said that this was a loss of almanac and a 12+ minute time period was required whilst stationary to update the almanac. When I did this the problem was fixed.

I’m an intermittent user of GPS navigation – 10 days has gone by without me using it. Starting from the same location as I switched it off, once again it appears I’ve lost the almanac. It came back after about 10 minutes of being stationary. The date/time on the TTN2 software GPS page was hunting anything up to two years ago before finally locking and I had no more trouble for the rest of the day with several different journeys.

My questions are these – (a) is the loss of almanac to be expected if you don’t use the software for extended periods and (b) is there any way of manually inputting the date/time in these circumstances (I suspect not) so the locking-on time is reduced?
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Tony
nuvi 2460LT plus Brodit mount

DavidW · Posted: Fri Feb 20, 2004 2:39 pm Post subject:

Your problem probably wasn't a loss of almanac - it was that the stored position and time data was corrupt and it took your GPS a long time to realise this before deciding to cold start.

If this happens again, then in TomTom Navigator 2, tap and hold on the map view at roughly your current location. Choose "Reset GPS for this location", and if the necessary support exists in the GPS driver (as it does for SiRF based GPSes - you don't say what GPS hardware and settings you're using), the GPS will be given a time, date and location to help it fix. That should reduce the time to fix to less than a minute.

David

Mearns · Posted: Fri Feb 20, 2004 3:39 pm Post subject:

Thanks for that David. The hardware etc is IPAQ 2210, TTN 2.24 and GPS 2.08, plus TT Bluetooth Receiver. The situation is probably not helped by the fact that my start point at home is about 300 yards off the nearest road which TTN2 doesn't seem to like for route calculation.
_________________
Tony
nuvi 2460LT plus Brodit mount

DavidW · Posted: Sat Feb 21, 2004 2:07 pm Post subject:

Next time it happens, try the fix I've suggested. I believe it should work just fine on your setup.

David

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