question about GPS

Discussion in 'Apple Watch' started by matt9013, Aug 19, 2016.

  1. matt9013 macrumors 6502

    matt9013

    Joined:
    Oct 27, 2013
    #1
    So if the AW2 does have built in GPS does that mean that I won't need my phone for Runkeeper or mapping my runs etc? I can go without my phone?
     
  2. exxxviii macrumors 65816

    exxxviii

    Joined:
    May 20, 2015
    #2
    Theoretically, if the future watch has a native GPS receiver, then it should be able to do fully independent distance and mapping for fitness activities.
     
  3. fischersd macrumors 601

    fischersd

    Joined:
    Oct 23, 2014
    Location:
    Kitchener, Ontario, Canada
    #3
    ....if it has the mapping data pre-downloaded from the iPhone (or your local wifi network). Unless it has a cellular connection the mapping data needs to be resident on the watch. (now, could it do approximate distances, just with GPS data? Yep).

    Also, it could remember your routes. Getting better accuracy over time.
     
  4. Julien, Aug 20, 2016
    Last edited: Aug 20, 2016

    Julien macrumors G3

    Julien

    Joined:
    Jun 30, 2007
    Location:
    Atlanta
    #4
    I think you are confusing (turn by turn) navigation mapping with map tracking. The OP is asking about map tracking data. There is no need to download any map data. Map tracking works by simply using GPS to record your current lat/log coordinates and then transfers this data to your iPhone (in the case of the rumored GPS enabled :apple:Watch 2) to build a map of your route.
     
  5. fischersd, Aug 20, 2016
    Last edited: Aug 20, 2016

    fischersd macrumors 601

    fischersd

    Joined:
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    Location:
    Kitchener, Ontario, Canada
    #5
    Yep, it'll just use the GPS coordinates to map the route and send data to the phone - there just won't be any correlation to streets, etc without a data connection or downloading of mapping data.

    Edit: One more thing though. I wonder just how accurate the GPS is going to be? Not a lot of room in there for antennae. When we first started doing GPS in phones, they were inaccurate as all hell (compared to using a paired bluetooth GPS puck), but then we got aGPS from the wireless carriers (assisted GPS, utilizing signal strength triangulation from cell towers). With no cellular radio, you have the potential that the GPS will be WAY off at times as it'll only get 2 or 3 satellites to get your location from.
    Others have solved this (Garmin for example), but they're also doing a LOT less in their watches. It's going to be interesting to see how accurate this is.
     
  6. kdarling, Aug 20, 2016
    Last edited: Aug 20, 2016

    kdarling macrumors demi-god

    kdarling

    Joined:
    Jun 9, 2007
    Location:
    First university coding class = 46 years ago
    #6
    Could be good or bad :)

    This guy did a full test of many running watch GPSes. He got widely differing results, with often the older and larger devices doing better:

    http://fellrnr.com/wiki/GPS_Accuracy

    A common misconception, brought about by a verbal slip on Jobs' part during a demo of the first non-GPS equipped iPhone.

    A-GPS for smartphones only means downloading the latest satellite status and orbits (and possibly a rough guess at your location using a cell id) from a terrestrial Assistance server over a fast data network, versus slowly searching for and downloading the same info from the satellites themselves at only 50 bps (which can take over ten minutes).

    Yes, your last known position, or a rough location derived from cell or WiFi locating methods, can be used to seed a rough initial position calculation, but those are all considered separate non-GPS related locating methods. (There are combination methods with names like E-GPS and X-GPS, but they're different from A-GPS.)

    Even with a cellular radio that can happen, since as noted above, it's only used as a network path to download satellite info or as a way to get a rough first position estimate... both of which should be obtainable via the host iPhone before you set out.

    In other words, the suggested procedure will probably be to sync your Watch with your iPhone's GPS position and satellite info, then you can go on your phone-less run with a good starting location and updated satellite orbital data (which would otherwise be out of date after about four hours and have to be downloaded from each satellite).
     
  7. exxxviii, Aug 20, 2016
    Last edited: Aug 20, 2016

    exxxviii macrumors 65816

    exxxviii

    Joined:
    May 20, 2015
    #7
    Unless Apple gets in the way and screws it up, there is no reason to think that GPS in a future AW would be any less accurate than any other GPS-enabled watch on the market. GPS implementation is pretty mature now.
    This scenario is so rare, you might as well put it in the "never" category. I have thousands of miles a year running, cycling, and swimming with multiple devices, and it is extremely rare that any of them will totally miss on location. And, if you wait a minute or two longer, the device will get a GPS lock and you will be good to go. I have maybe run once or twice in my life when the watch was struggling to get a GPS lock and I ran anyway (it eventually got a lock and caught up during the run). My current watch will get a dead on GPS lock in 5 seconds.
     
  8. Julien, Aug 20, 2016
    Last edited: Aug 20, 2016

    Julien macrumors G3

    Julien

    Joined:
    Jun 30, 2007
    Location:
    Atlanta
    #8
    GPS in watches has been the norm and very accurate for years now. A lot of the accuracy is related to smoothing (processing) of the GPX/TCX files. Here is a run I just did today and one is my iPhone and one is my Garmin watch.

    [​IMG]
    [​IMG]
    --- Post Merged, Aug 20, 2016 ---
    Just for kicks here is a couple of closeups in satellite mode.

    [​IMG]
    [​IMG]
     
  9. chiefs1968 macrumors member

    Joined:
    Feb 27, 2016
    #9
    --- Post Merged, Aug 20, 2016 ---
    With all aspects pointing to GPS on Watch 2, will a compass app work on the apple watch.
    I had the Moto 360 2 sport and it has GPS but compass did not work.
     
  10. username: macrumors 6502a

    Joined:
    Dec 16, 2013
    #10
    Pretty sure the compass in the iPhone uses a particular sensor not related to GPS. They would have to add that to the watch for it to have a compass.
     
  11. Julien, Aug 21, 2016
    Last edited: Aug 21, 2016

    Julien macrumors G3

    Julien

    Joined:
    Jun 30, 2007
    Location:
    Atlanta
    #11
    Correct, a digital compass is a dedicated chip that uses the Hall effect and has nothing to do with GPS. The limited space may preclude its inclusion. Here is a description.

    https://en.wikipedia.org/wiki/Hall_effect
     
  12. Vanilla35, Aug 31, 2016
    Last edited: Aug 31, 2016

    Vanilla35 macrumors 68030

    Vanilla35

    Joined:
    Apr 11, 2013
    Location:
    Washington D.C.
    #12
    I'm very interested to see how they end up handling this. I personally would be satisfied with a bare minimum of just having a preloaded map. I use this with Google Maps and turn by turn works wonders with that. The map is also a huge area (albeit at a hefty size of 200-300MB, it is most convenient for repeat use). It practically covers the entire DC Metro Area, which for most who live and work here, would cover the entire area in which they would ever travel unless they were making a trip somewhere.

    If syncing were used, then I don't see much benefit over using a preloaded map, aside from having to load a map (storage) - it still requires the phone to be at a point somewhat near to the phone for it to be of any use. Or are we talking like greater than 1 mile closeness (seems unlikely)?
     
  13. anthonymoody macrumors 68020

    Joined:
    Aug 8, 2002
    #13
    You guys may or may not be aware of this, but the early betas of WatchOS3 had decently accurate route tracking on the current AW even without the phone present. When you got back home and re-paired your watch with your phone, the map that appeared in the workout in the Activity app on the phone had a pretty accurate map, somehow created by the watch by itself.

    There was an extensive thread about it, but it died because Apple removed the functionality as of, I believe, beta 3. People theorized that it involved clever combinations of wifi triangulation, using the gyros, etc. to somehow figure out the location.
     

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