02-25-12 08:04 PM
31 12
tools
  1. blackberrystorm1234's Avatar
    I'm using the mapdroid google app for offline gps. I find that my location is off by 100 meters. Anyone know how to calibrate or make the gps more accurate ? Is it possible that my gps on the Playbook is defective ? (I do not have 3G or wifi available when I'm in my car.)
    12-11-11 06:48 PM
  2. MedChemist's Avatar
    I have posted about gps on a couple of other threads. I don't believe your PB gps is defective. More than likely you could not acquire enought satelites to get greater accuracy. There are a lot of factors that play into how well the software places you on a map. One how good the base map coordinates are. How good the receiver/signal to noise is, and how many birds are line of sight to your device. The more birds, and stronger their signals the better. There may be some software issues as well. My experience varies a great deal even with high end Garmin devices. One day dead on later in the day 50 to 100 meeters off from the same location. in the woods i loose signal frequently and thats with a Garmin GPS.

    That said i have had days withe the PB where it couldn't find the minimal three number of sats it needed to locate me T all before the PB timed out. Othertimes after about 5 mins. it got me to within 20 feet which isn't that bad considering with the best equipment usually the best you can get is about 9 feet.
    Rob Robertson likes this.
    12-11-11 08:24 PM
  3. blackberrystorm1234's Avatar
    I have posted about gps on a couple of other threads. I don't believe your PB gps is defective. More than likely you could not acquire enought satelites to get greater accuracy. There are a lot of factors that play into how well the software places you on a map. One how good the base map coordinates are. How good the receiver/signal to noise is, and how many birds are line of sight to your device. The more birds, and stronger their signals the better. There may be some software issues as well. My experience varies a great deal even with high end Garmin devices. One day dead on later in the day 50 to 100 meeters off from the same location. in the woods i loose signal frequently and thats with a Garmin GPS.

    That said i have had days withe the PB where it couldn't find the minimal three number of sats it needed to locate me T all before the PB timed out. Othertimes after about 5 mins. it got me to within 20 feet which isn't that bad considering with the best equipment usually the best you can get is about 9 feet.
    Thanks MadChemist.

    Is there any settings I can change for the GPS ? You mentioned a minimal of 3 sats. Is there any app or settings I can check to see how may sats my PB is receiving ?

    Which GPS program are you using with the Playbook ? Besides mapdroid, is there any other off-line gps program that works with the Playbook ?
    12-11-11 09:05 PM
  4. MedChemist's Avatar
    No - GPS receivers are multi channel. It should be attempting to receive from as many as it can "see" in the sky. However at different points during the day due to conditions, one may only receive one or two. Some times you might get four or five.
    12-12-11 10:06 AM
  5. FF22's Avatar
    I presume Mapdroid is an android app? I am not on the beta. I don't know if any of the various gps apps show the satellites.
    12-12-11 11:08 AM
  6. Spencerdl's Avatar
    I just used bing, and its right on target, I've read that the gps has been a problem on some playbooks. I wonder why.
    12-12-11 11:22 AM
  7. RicThot's Avatar
    Using Magellan Compass, I see my location pointer right over the roof of my house.
    But I did see it wayyyyyyy off (tens of KMs) on some occasions - using Maverick for Android and GeoRendr, so I wonder if this wasn't caused by the app itself.
    12-12-11 11:32 AM
  8. blackberrystorm1234's Avatar
    I'll try Maverick and see if it is more accurate the mapdroid.
    12-13-11 09:38 PM
  9. blackberrystorm1234's Avatar
    I'll try Maverick and see if it is more accurate the mapdroid.
    Even using Maverick, I'm still off by 100 meters. Sometimes Maverick shows me 100 meters east of my actual location, sometimes it's a 100 meters south of my location. It's a bit worrysome as I would hate to think I have a defective gps chip.

    How long do I have to stand outside in an open field to pickup 3 or 4 satallite signals ? I don't know much about gps, but I've heard there is a difference between gps and A-gps and one of these can take up to 13 minutes to lock onto enough satallites to be accurate.
    12-15-11 10:34 PM
  10. BuzzStarField's Avatar
    Using Magellan Compass, I see my location pointer right over the roof of my house.
    But I did see it wayyyyyyy off (tens of KMs) on some occasions - using Maverick for Android and GeoRendr, so I wonder if this wasn't caused by the app itself.
    The way that GPS events are handled by the app definitely have a bearing. The initial OS implementation was quite flaky actually and we developers learned some tricks to improve the performance. If I remember correctly, the events sometimes stopped being sent for no apparent reason. Or if you grabbed the very first event, you were in trouble because an accurate fix is only available on the 6th, 7th or 8th event. Perhaps the workarounds that we implemented are still required - it's hard to say. I have Magellan too and there is never a problem. I have received no complaints about the implementation in my app either.
    12-15-11 10:57 PM
  11. peter9477's Avatar
    If this is a "fresh" unit, you might have to stand there for a number of hours before it's got the ephemeris data from all the satellites. Very likely in half an hour or less it will have it from most satellites currently visible, however, and in any case it's a near certainty you'll have well over 4 at almost any time of the day, unless you live in strange places.

    This is pure standalone GPS though, not assisted (yet). Not sure about the 13 minutes, but it can be a while.

    If you consistently get a reading 100 metres off, you're probably in some location (near a tall building?) where you're getting reflections that are throwing it off. There's not much reason it should be wrong otherwise.

    I've posted in the past a number of things, which are still good advice. Here's a subset:

    1. don't cover the lower right corner (to right of logo) with your hand, as that's where the antenna is
    2. consider resetting your tablet first if it's not getting readings at all... there's a bug that can make GPS fail hard under some conditions, until you reset it again
    3. try disabling the radios (BT and WiFi) as on some units the WiFi at least can significantly screw up the GPS signal (at least with current software)
    12-15-11 10:58 PM
  12. FF22's Avatar
    GENERALLY, once you have locked in satellites, the next time should be fairly quick. A gps downloads an almanac of where satellites are and uses that to calculate where they should be based on the time difference for the next use. If you move away from that location (I don't know distances) or don't use it for a while, it will again need to find the current position of satellites. But if you use it to drive 100 or 500 miles, it will be gathering that info. So turn if off and back on the next day and it should find you. Even a day or two later, it should be reasonably fast. It does not have to be totally open but it helps.

    I can get the pb to find me inside my woodframe/shingled home on its second floor but not on the first floor.
    12-15-11 11:02 PM
  13. blackberrystorm1234's Avatar
    i find, when I turn off my wifi, then my mapdroid program does not locate me. I thought it was suuposed to work without a wifi connection (ie: offline mode) ?
    12-17-11 12:28 AM
  14. lebob23's Avatar
    Mine is 300ft off on a good day
    12-17-11 07:19 PM
  15. blackberrystorm1234's Avatar
    I finally had a chance to do some proper testing outside. I do not have any wifi or 3G service for my playbook. While walking around outside, I started up mapdroid. Within about 1 minute (and periodically clicking the "my location" option) it pinpointed me on the map to within a few feets of my location. So I guess my GPS does work properly and I do not need wifi or 3G service at all.
    mossfoot likes this.
    12-21-11 09:38 PM
  16. FF22's Avatar
    I finally had a chance to do some proper testing outside. I do not have any wifi or 3G service for my playbook. While walking around outside, I started up mapdroid. Within about 1 minute (and periodically clicking the "my location" option) it pinpointed me on the map to within a few feets of my location. So I guess my GPS does work properly and I do not need wifi or 3G service at all.
    If an app is designed correctly and the map is itself fairly accurate, you have all you need. The pb has an independent gps receiver and if working, it would pass the info to the app and the app can use onboard maps. I'm looking forward to trying what you are using under OS2.
    12-22-11 12:23 AM
  17. ribsandbbqbeef's Avatar
    Thx 4 the info on PB's GPS. What is MapDroid listed as in app world? i couldn't find it under search or in the GPS area. Thx.

    edit/PS: does Magellan require constant web access,eg tethering, or can it function standalone like MapDroid?
    Last edited by ribsandbbqbeef; 12-22-11 at 03:47 PM.
    12-22-11 03:14 PM
  18. ribsandbbqbeef's Avatar
    NM, found out MapDroyd is an android app, and Magellen needs continuous web access to work well for gps nav.
    12-22-11 04:15 PM
  19. blackberrystorm1234's Avatar
    Yes, Mapdroid is an android app. You'll have to update to the 2.0x beta version and then load the mapdroid.bar file.
    12-27-11 10:57 PM
  20. k1ward's Avatar
    My Playbook, with Bing, shows my in my living room. I am actually in my office which is about 20 feet away. Close enough...
    01-14-12 08:18 PM
  21. KennethD's Avatar
    OK is there a way to calibrate the GPS? I have 2 playbooks and one seems to work better than the other. My 16 sometimes has trouble acquiring a signal but once it does its fine. The 64 gig is faster but less accurate. Is there any solution. For example blutorq reads my speed perfect on the 16 gig but is all over the board on the 64.
    Oh instead of a new thread I thought I'd hijack this one.

    Sent from my AT100 using Tapatalk
    02-24-12 05:02 PM
  22. peter9477's Avatar
    GPS has no calibration.

    I think it's likely the cause of the difference in accuracy you're seeing is that the one unit has up-to-date ephemeris data on more of the satellites than the other, so it is able to use more of them in calculating your position. If I'm right, leaving both running GPS for some hours, or using both regularly over some days (it's effectively random which satellites are up and which are down during a given period of the day), will eventually result in them having nearly identical results.

    It's also possible one has a defect, or that they were built at quite different times and there's been a design change that improved things (or, conceivably, a tradeoff that made it worse in favour of improving something else).

    But there's no calibration possible...
    02-24-12 05:24 PM
  23. KennethD's Avatar
    GPS has no calibration.

    I think it's likely the cause of the difference in accuracy you're seeing is that the one unit has up-to-date ephemeris data on more of the satellites than the other, so it is able to use more of them in calculating your position. If I'm right, leaving both running GPS for some hours, or using both regularly over some days (it's effectively random which satellites are up and which are down during a given period of the day), will eventually result in them having nearly identical results.

    It's also possible one has a defect, or that they were built at quite different times and there's been a design change that improved things (or, conceivably, a tradeoff that made it worse in favour of improving something else).

    But there's no calibration possible...
    Thank you. The 64 was purchased later (I know it could've been made earlier) and it never had 1.08 on it. It was a clean install to 2.0 I unwrapped it on Wednesday and fired her up. Not that it should matter and I don't think I want to return it. I was just hoping there was a fix. I will try the leaving it on and using it. That might just help it was. A cloudy crappy day here. Maybe that had an effect.

    Sent from my AT100 using Tapatalk
    02-24-12 05:53 PM
  24. yanicmb's Avatar
    im does not work at all it can never find my location ever
    02-24-12 06:34 PM
  25. mossfoot's Avatar
    I finally had a chance to do some proper testing outside. I do not have any wifi or 3G service for my playbook. While walking around outside, I started up mapdroid. Within about 1 minute (and periodically clicking the "my location" option) it pinpointed me on the map to within a few feets of my location. So I guess my GPS does work properly and I do not need wifi or 3G service at all.
    Just a shout-out thanks for the tipoff for mapdroid. I needed an offline map app and am going to look into that tonight.
    02-24-12 07:02 PM
31 12
LINK TO POST COPIED TO CLIPBOARD