Is it possible to collect accurate Z coordinate values with Collector and Trimble R2?

DonRodgers

We have been told that the ESRI software does not calculate the correction from HAE to MSL. We have also been told that people are, indeed, using this equipment configuration to do so. And it seems like it should be poosible.

LanceCole

Don,

Below are the instructions to convert the HAE to actual elevation transformation from the data obtained from high accuracy GPS using Collector.  I have assumed the following:

1. You have configured the database receiving the data to support the GPS metadata.  In particular the ESRIGNSS_LATITUDE, ESRIGNSS_LONGITUDE and ESRIGNSS_ALTITUDE fields.  If you have not, this can easily be added using the Add GPS Metadata Fields tool in ArcGIS Pro. I can also provide additional instructions, if needed.
2. You stated your GPS is configured or is receiving data in the GCS NAD 1983 (2011) for horizontal data and I am assuming it is configured to receive vertical data in an ellipsoidal based, North American NAD 1983 (2011) datum coordinate system.  It is critical that you have the correct coordinate systems for this data.  ArcGIS collector stores this raw data in the Latitude, Longitude and Altitude fields noted above.
3. Insure your coordinate systems have been updated.  Go to my.ESRI.com and download and install the Current ArcGIS Coordinate System Data - I believe the current version is 10.7.10000.  You can check your Windows Control Panel > Programs and Features to see if this is installed.
4. If you have not already, go to the Github ESRI / Collector-tools site and download the tools for collector.  I recommend you download the entire tool set using the Clone or download button, save and extract to a common location.

Now lets get to the actual transformation of the 2D data stored in ArcGIS Online (AGOL) to 3D data with the correct elevation data. 

• Open ArcGIS Pro and load the original AGOL data into a map.
• Right-Click the feature and select Data > Export Features and point to a local GDB.  You will be working with is local copy of the data.
• On the Insert Tab select Toolbox > Add Tool box
• Navigate to the folder you downloaded from GitHub and add CollectorUtilis_Pro.tbx.  This should be located in the folder ...\collector-tools-master\CollectorUtils\pro
• Go to Catalog in ArcGIS Pro and select Toolboxes > CollectorUtilities_Pro.tbx > GeneralUtils > ProjectZ

• In the ProjectZ tool, select the newly created feature Class in the local GDB for the Input Features.  Mine is called SurveyPointFeatures_Copy for this example.  A warning triangle will appear as the data does not have z data - ignore
• For the Input Coordinate System - Click on the globe and select the following for Current XY and Z - based upon assumptions above

Click on the Current XY box then select:

    Geographic coordinate system > North America > USA and territories > NAD 1983 (2011)

Click on the Current Z box and select:

    Vertical Coordinate System > Ellipsoidal-based > North America > NAD 1983 2011

Click OK

• Confirm the X-Value is set to the Longitude field, the Y-Value is set to the Latitude field and the Z-Value is set to the Altitude filed.  These should populate by default.
• Enter an output feature class - I used "SurveyPointFeatures_ProjectZ" in the same GBD
• For the Output Coordinates - Click on the Globe and Input the following for Current XY and Z - based upon assumptions above

Click on the Current XY box then select:

    Geographic coordinate system > North America > USA and territories > NAD 1983

Click on the Current Z box and select:

    Vertical Coordinate System >  North America > NAVD 1988

        Select NVAD 1988 even if you want ftUS.  It is not possible to directly translate to NAVD88 (height) (ftUS)

Click OK

• A Geographic Transformation will automatically populate, you can change to other options but typically this is the optimal transformation for the Input and Output coordinate systems entered into ProjectZ

• Click "Run" - This will use the Latitude, Longitude and Altitude fields to create a new feature class as named above in NAD 1983 and NVAD 1988 as 3D data points.

If you need to convert the elevation data to US Feet, continue with the following. If you only need elevation in meters skip this step.  This step is only converting the NVAD 1988 in meters to NAVD88 (height) (ftUS)

• In the Geoprocessing tab search for and select the "Project" tool, it should be in the data management tools
• For the input Feature Class select the feature class created above - SurveyPointFeatures_ProjectZ in my example
• Input a new feature class name for the Output Feature Class - I chose SurveyPointFeatures_Feet
• For the output Coordinate - Click on the Globe and Input the following for Current XY and Z

Click on the Current XY box then select:

    Geographic coordinate system > North America > USA and territories > NAD 1983

Click on the Current Z box and select:

    Vertical Coordinate System >  North America > NAVD88 (height) (ftUS)

Click OK

• Check the Vertical Box

• Click Run

One last step. 

• In the Geoprocessing tab search for and select the "Add XY Coordinates" tool, it should also be in the data management tools
• Select the SurveyPointFeatures_Feet or SurveyPointFeatures_ProjectZ feature from above and run the tool.  This will add X,Y and Z data to the feature. 
• Open the attribute table and the added Z value is your Elevation in feet or meters depending which feature you are using.

I hope this helps you with adding the elevation data to your data.  As noted previously, please double check the coordinate system your GPS is running on.  This is critical for accurate translation.  You can also select a different output coordinate system if I assumed the incorrect system.  For example we output to a projected coordinate system rather than a geographic system.  So we set our Output Current XY to Projected coordinate system > State Plane > NAD 1983 (2011) (US Feet) > NAD 1983 (2011) StatePlane Ohio North FIPS 3401 (US Feet).  This will return Northing, Easting and Elevation, rather than Lat, Long and Elevation. 

Lance