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iOS device showing different position than Android device using Propeller Mobile app with Catalyst.

  • 1.  iOS device showing different position than Android device using Propeller Mobile app with Catalyst.

    Posted 08-25-2025 10:01

    We are using a catalyst 10 subscription and DA2 utilizing mock location with the Propeller mobile app to do rough layout of features.    We have found that when we look at the position in the Propeller mobile app on an iphone versus android device they show up in different locations.  In the image below you can see the blue dot (pole location) using the android device is centered over the circular drain location.    However using the same subscription and hardware using an iphone it shows the same position shifted up and to the left indicated by the red arrow.

    The mobile manager settings were the same on both devices
    When looking at the position information within mobile manager the postion looks similar.
    Is there a reason we would see different locations based on the type of device within Propeller?


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    Trent Walters
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  • 2.  RE: iOS device showing different position than Android device using Propeller Mobile app with Catalyst.

    Posted 08-25-2025 16:24

    Hi Trent,

    I believe Propeller Mobile uses location services on both platforms. In this case there are a couple of things at play, it might be easier if I summarise the location services difference on each platform:

    Android

    Location: Provided by the mock location provider (assuming you have TMM configured as the mock location app)

    Accuracy: Whatever is provided by the mock location app (I can see your achieving ~4" as expected for your subscription)

    Height: Both ellipsoidal and orthometric heights (from Geoid setting in TMM) available though mock location

    Reference frame: Whatever is configured in TMM for GNSS output. If Auto then TMM will chose whichever reference frame is most suitable for your position. In your case your GNSS output is NAD83(2011) at Epoch 2017.5 (for your location Epoch 2010 might be more appropriate?).

    iOS

    Location: Provided to iOS direct from the DA2

    Accuracy: At best iOS location services will report an accuracy of 5m when used with an external GNSS receiver

    Height: Ellipsoidal height from the receiver only

    Reference frame: Whatever the correction source in use is using. In this case your DA2 is using Trimble RTX, which uses ITRF 2020 current Epoch

    I think the most likely reason for the difference you're seeing is the coordinate system difference between the ITRF 2020 current epoch position from RTX and NAD83 (2011), which for your location would be a difference of ~4'. There is no simple way around this unless it's possible to do some transformation within Propeller, which I don't believe is the case. We do make it possible for partner applications to integrate directly with our receivers through TMM to enable high accuracy, I will see if we can reach out to Propeller on that. Feel free to reach out to me directly if you'd like to discuss further.

    Regards,



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    Mark Kellaway
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  • 3.  RE: iOS device showing different position than Android device using Propeller Mobile app with Catalyst.

    Posted 09-02-2025 16:20

    Hey Trent,

    Mark is probably on the right track with this suggestion.  As he mentioned, there's not a clear cut way to address this, but feel free to shoot me an email and we can address this together over a call.  We have developed some ways around this for when SiteVision experiences a similar issue as it relates to the reference frames, perhaps they could work for you.  In near the future you should be able to view your 2D plans like this in SiteVision as well, along with improved solutions for differing reference frames. 

    Bryer



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    Bryer Palmer
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    Original Message


  • 4.  RE: iOS device showing different position than Android device using Propeller Mobile app with Catalyst.

    Posted 12-10-2025 17:47
    Edited by Zach Edwards 12-10-2025 17:47

    The best bet is to not use iOS in this situation. Apple, of course, had to do things differently. if you are using a Trimble receiver, you want to make sure that the app provider uses Trimble's TPSDK or Web socket protocol. This will solve the iOS issue. The app provider would have to work with Trimble on getting this put in place.



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    Zach Edwards
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    Original Message