Mapping and GIS Solutions Community

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?

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,

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?