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nucleus Occasional Visitor
Joined: Jun 29, 2007 Posts: 2
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Posted: Thu Feb 28, 2008 10:58 pm Post subject: |
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Ok, here's what I have experienced:
Hardware - XDA Orbit (HTC P3300)
Software - Navigator6 and CoPilot7 (not at the same time!)
This evening I had a repeat of the same problem as others are having and I had a few days ago - positional error of about 200m to the NW from true position. This happened with both Navigator and CoPilot so cannot be due to any QuickFix download error? Also, while the TT software just couldn't cope and steadfastly refused to show the correct position, CoPilot would figure things out after about 2 minutes of travelling in roughly a straight line. Things were then fine until a sharp change of direction which would then throw it into confusion until another period of straight travel after which it would 'find itself' again.
So, my theory is that there is a satellite up there that's sending out slightly duff data - CoPilot is able to figure out after a while that what it's getting from the 'rogue' satellite doesn't agree with the other 6 and compensate, while TomTom isn't that clever!
This might also explain why the problem is intermittent and probably wont occur tomorrow morning since the satellite in question will be over the horizon?
All this from someone who knows next to nothing about GPS so feel free to shoot me down if none of the above makes sense.... |
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portman Frequent Visitor
Joined: Nov 10, 2005 Posts: 435 Location: Dorset
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Posted: Fri Feb 29, 2008 12:18 am Post subject: |
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It happening cos its a leap year, that extra day is reeking havoc with the time/date!!!!!!! _________________ Samsung Mega
Tomtom 500
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lamplight Regular Visitor
Joined: Sep 13, 2004 Posts: 130
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Posted: Fri Feb 29, 2008 12:18 am Post subject: |
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It's getting a bit galling. Every single night for the past week or so, my positioning goes haywire at the same spot for about a mile on my way home from work and then 25 miles further on as I approach home. Tried it with and without QF and still the same result. I look forward to this being recognised as an issue by TomTom and, if possible, to its resolution. And it's interesting that a colleague with a TTOne is having similar issues all of a sudden. |
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Philgo Regular Visitor
Joined: Jan 02, 2008 Posts: 80
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Posted: Fri Feb 29, 2008 7:03 am Post subject: |
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nucleus wrote: | This might also explain why the problem is intermittent and probably wont occur tomorrow morning since the satellite in question will be over the horizon? |
The satelitte are in a Geostationary orbit, which means there position doesn't change much.
http://en.wikipedia.org/wiki/Geostationary |
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Philgo Regular Visitor
Joined: Jan 02, 2008 Posts: 80
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Posted: Fri Feb 29, 2008 7:08 am Post subject: |
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mikealder wrote: | Is everyone that is experiancing this fault using TomTom Home to download the Quick GPS data? - the reason I ask is that I do not do this with my devices and I have not experianced the fault at all. - Mike |
Mike do you not bother with the ephemeris stuff then.
How about if the people with bother try deleting the contents of their ephem folders and restore the old files from an earlier backup, this then will completely rule out the QF stuff. |
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Oldboy Pocket GPS Moderator
Joined: Dec 08, 2004 Posts: 10642 Location: Suffolk, UK
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Posted: Fri Feb 29, 2008 7:17 am Post subject: |
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Philgo wrote: | nucleus wrote: | This might also explain why the problem is intermittent and probably wont occur tomorrow morning since the satellite in question will be over the horizon? |
The satelitte are in a Geostationary orbit, which means there position doesn't change much.
http://en.wikipedia.org/wiki/Geostationary | A correct concept for TV satellites, but doesn't apply to GPS.
This is an extract from the GPS FAQs Page.
Quote: | · How many GPS Satellites are orbiting the earth ?
There are just under 30 navigational satellites orbit the Earth and more may be added in the future. Each satellite makes one Earth orbit every 12 hours. The satellite's orbit repeats almost the same ground track (as the earth turns beneath them) once each day. The orbit altitude is such that the satellites repeat the same track and configuration over any point approximately each 24 hours (4 minutes earlier each day). There are six orbital planes (with nominally four Space Vehicles in each), equally spaced (60 degrees apart), and inclined at about fifty-five degrees with respect to the equatorial plane. This constellation provides the user with between five and eight Space Vehicles visible from any point on the earth. |
_________________ Richard
TT 910 V7.903: Europe Map v1045
TT Via 135 App 12.075: Europe Map v1120 |
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mikealder Pocket GPS Moderator
Joined: Jan 14, 2005 Posts: 19638 Location: Blackpool , Lancs
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Posted: Fri Feb 29, 2008 8:41 am Post subject: |
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Philgo wrote: | Mike do you not bother with the ephemeris stuff then.. | For a start getting this data requires a connection via TomTom Home which is the second thing I don't bother with as I simply don't trust it.
The devices I have operate quite happily without the Quick GPS, if used regularly there is little point downloading data to it via the internet - Mike |
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nucleus Occasional Visitor
Joined: Jun 29, 2007 Posts: 2
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Posted: Fri Feb 29, 2008 9:02 am Post subject: |
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To restate the point from earlier, this isn't just a TomTom (hardware or software) problem because affects CoPilot navigation software running under WM6 as well. What's hard to understand is why some people are seeing the problem and others not?
FWIW I also have never used TT Home with my XDA; on the other hand I do use QuickGPS which is a service provided by the manufacturer HTC. Never had any location accuracy problems until last week.
Still think on balance that one of those satellites needs rebooting! |
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Nigel42 Occasional Visitor
Joined: Jan 05, 2007 Posts: 51
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Posted: Fri Feb 29, 2008 9:05 am Post subject: |
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FAO Mike
Yes I am using quickfix, On a 48 hour basis. BUT after the download everything works fine, for a number of hours in fact.
The problem always occurs at the same time of day but not every day.
Hope this helps.
Has anyone heard from Tomtom or is the silence deafing? |
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Hoppy Regular Visitor
Joined: Jun 16, 2004 Posts: 241 Location: Lincoln
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Posted: Fri Feb 29, 2008 9:47 am Post subject: |
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When I did an update last night to QuickGPSfix then switched my 520 on it showed my home/start posistion about 100 yards out. After I had switched maps a couple of times between UK and USA then checked again and my home/start posistion was correct again. Timescale was about 15 mins. Which would tell me that the GPSfix update was incorrect then when the unit aquired the Satalites properly it corrected the posistion. _________________ TomTom Go 950 Live.
App 9.054
Europe v8.50
NA 2GB v8.45 |
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shadamehr Banned
Joined: Apr 25, 2006 Posts: 507
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Posted: Fri Feb 29, 2008 1:34 pm Post subject: |
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This seems to be getting more and more common, instead of less frequent, once only glitches.
Alas, as I posted elsewhere, I was unable to get any further info out of TomTom, because all they said was "we'll exchange your unit".
If users GENUINELY are getting this on other devices however, or those that don't use QGPSFix also see it happen, then it points to something other than the QuickGPSFix file being to blame.
But it's always all to easy to speculate. I'd like a real response from TomTom ideally.
I still think it very important for this thread to expand and grwo, if others have this issue though, so the word might actually reach TT.
Curious. |
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Andy_P Pocket GPS Moderator
Joined: Jun 04, 2005 Posts: 19991 Location: West and Southwest London
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Posted: Fri Feb 29, 2008 2:25 pm Post subject: |
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Same again driving home last night.
Time: about 20:15
Location: South West London
Started off about 150-200 yds due south of correct position, but it steadily improved over twenty minutes or so. After half an hour was back on track.
Much easier to see if you do NOT have a route set (as TT cheat even more than usual with the snapping to roads and assumes you are staying on "the route").
Signal strength was excellent at all times, 9-11 satellites.
Same route (in reverse) this morning. Spot on all the way.
What IS going on? |
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Philgo Regular Visitor
Joined: Jan 02, 2008 Posts: 80
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Posted: Fri Feb 29, 2008 5:59 pm Post subject: |
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Oldboy wrote: | Philgo wrote: | nucleus wrote: | This might also explain why the problem is intermittent and probably wont occur tomorrow morning since the satellite in question will be over the horizon? |
The satelitte are in a Geostationary orbit, which means there position doesn't change much.
http://en.wikipedia.org/wiki/Geostationary | A correct concept for TV satellites, but doesn't apply to GPS.
This is an extract from the GPS FAQs Page.
Quote: | · How many GPS Satellites are orbiting the earth ?
There are just under 30 navigational satellites orbit the Earth and more may be added in the future. Each satellite makes one Earth orbit every 12 hours. The satellite's orbit repeats almost the same ground track (as the earth turns beneath them) once each day. The orbit altitude is such that the satellites repeat the same track and configuration over any point approximately each 24 hours (4 minutes earlier each day). There are six orbital planes (with nominally four Space Vehicles in each), equally spaced (60 degrees apart), and inclined at about fifty-five degrees with respect to the equatorial plane. This constellation provides the user with between five and eight Space Vehicles visible from any point on the earth. |
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Thanks for putting me right Oldboy. That could mean then that there is a problem with a satellite, although perhaps not if shadamehr's new one works OK. |
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dhn Frequent Visitor
Joined: Oct 08, 2007 Posts: 2544 Location: Toronto CANADA
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Posted: Fri Feb 29, 2008 6:03 pm Post subject: |
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I do believe Andy nailed the reason in an earlier post....Aliens! |
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Trevor1234 Frequent Visitor
Joined: Apr 30, 2005 Posts: 810 Location: Milton Keynes
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Posted: Fri Feb 29, 2008 9:19 pm Post subject: |
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I have had my 720 for around three weeks now and have never connected to ‘Home’ since the initial setup. I too (same as Mikealder) never bother with the Quick GPS download. My 720 usually has my position before I have placed it in the car mount and put my seat belt on so I can’t see the point of the Quick GPS option.
Anyway, what I am trying to say is I have not suffered the from the ‘Wandering off route’ syndrome yet and if I do at some time in the future it will mean we can rule out the Quick GPS download as the culprit. _________________ Tomtom Go 720.
Navcore 9.510
Central and Western Europe v855.2884
GPS World Traffic cameras
Home 2.7
iPhone 3G |
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