Collector Support for High Accuracy RTK GPS Data Collection

[DanAllen]

We have an Arrow 200 RTK bluetooth GPS receiver to test.  Collector does not seem to know what to do with it.  It collects the xy points using the Arrow RTK location just fine, but the app otherwise does not appear to fully support High Accuracy GPS receivers like the TerraGo Edge app does.

I want to collect a point, and store attributes like elevation, HDOP, PDOP, Horz and vertical precision, and time stamp that come out of the Arrow RTK feed.  Is there a way to do this now with Collector, or do we need to wait for a future update from ESRI?

Thoughts?Jeff Shaner​

[DanAllen]

Anyone?

[ScottRutzmoser]

I am looking for this as well.

[DougMorgenthaler]

In the next few weeks we'll make our upcoming beta of Collector for ArcGIS available that will include support for high accuracy workflows.  If you are interested in participating, please send an email to collector4arcgis@esri.com​ and include the platform and receivers you would like to test.

Regards,

-Doug

[DanAllen]

This is great news.  Preliminary questions:

1. Will you be able to store Z values as an attribute?
2. Will there be an option to adjust the elevation value stored for pole height?
3. Can you pick a coordinate transformation, or will you have to collect points in WGS84?
4. Can you store values besides x/y/z as attributes such as horizontal and vertical precision, pdop, timestamp, #sats etc.?
5. Will this beta be available on android and iOs?
6. It is my understanding that apple rounds its core location to decimeter level at best.  Has this issue been resolved in collector to allow the external gnss receiver to overwrite apple's core location value to centimeter accuracy, or is that specific to the gps manufacturer and not a collector issue?

[MichaelDavis3]

What is your source for this?

1. It is my understanding that apple rounds its core location to decimeter level at best. Has this issue been resolved in collector to allow the external gnss receiver to overwrite apple's core location value to centimeter accuracy, or is that specific to the gps manufacturer and not a collector issue?

I have not experienced this at all developing for iOS.  The default logging mechanism in Objective C (NSLog) defaults the display of float numbers to 6 digits (approx 11cm for lat/long at the equator) but the core location data is a full float and you can set it to return as many decimal places as you think appropriate.  If an application is converting a float to string and only capturing the standard 6 decimal places that's on the developer not Apple.

[DanAllen]

Hi Michael,

When using EOS Bluetooth RTK receiver, you can see where the RTK location is 8 decimals and the apple core location that gets fed to Collector appears to be rounded to core location 6 decimals (or approx 1 decimeter as you said 11 cm).  I could be confusing the information I had discussed with the EOS developers, but it didn't sound as simple as just extending out 2 more decimals on the coding end, or they would have done it already.  I think there was an issue with getting apple to white list the apps.  Android didn't seem like an issue because you can allow mock locations.  Then there is the question of how many decimal places is Collector actually storing?

Either way, I hope the great folks at ESRI can provide some documentation in the next BETA release about how the RTK data is stored in terms of precision and decimal places, etc.

Dan

[DougMorgenthaler · Accepted solution]

Hi Dan-

Here are some answers to your questions:

1. Yes, you will be able to store the elevation value if you wish, though not a requirement.
2. We will support the ability to specify the antenna height, which will be included in the elevation value.
3. Selecting an appropriate coordinate system and datum transformation is supported.
4. Yes, much like altitude we will support storing additional position information as attributes.
5. The beta will be available on all three supported platforms (Android, iOS, Windows).
6. On all three platforms there should be no limitations beyond the receivers capabilities in terms of accuracy.

Hope this helps and look forward to your participation and feedback in the beta.

-Doug

[DanAllen]

Hi Doug.

Thank you so much for answering all of my questions.  I can't wait to give the BETA a try.  Sounds like your team has been hard at work adding improvements.  Those will be greatly appreciated.

Dan