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Measure the orthometric height in Field Maps

7096
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05-18-2021 04:47 AM
Hegik
by
Occasional Contributor

What the Field-Maps App is doing:

Right now our measurement crews connect their GNSS-antenna to their iPad (iPad Pro 11”, 2nd generation running iOs 14.3) and add points to our web-feature-layer. The height, which the app is saving is known as “Height Above Ellipsoid”. Germany (and other European countries) use another height called the “Normalhöhennull” (orthometric height). The Field-Maps app can display the “Normalhöhennull” but it will only save the (for us useless) “HAE”.

What is the problem:

If we want to measure the height of the GNSS-antenna, we always need to open the app of the antenna manufacturer, copy the (orthometric) height, and then we paste it into a field of the feature layer we specifically created for this purpose. This adds human error to the process, which is unfortunate. Another workaround would be post processing the data, but that would need a person who does that, and would probably add calculation error, so we would like to have it shown correctly in the first place.

How this will help us:

In the past few months we’ve invested in a lot of hardware (e.g. GNSS-Antennas, iPads, etc.) with the goal to simplify the process of our measurements, but with the wrong height it is more of an obstacle than a relief to use it. At the moment the data that the measuring crews are gathering, needs to be fixed by an ArcGIS Pro operator before it can be further processed and analysed by our CAD or laboratory staff. This adds big delays to our workflow.

Why this is important:

We as a German authority must work with our official German standards especially when we are measuring things. The “Normalhöhennull” is the standard for every German authority, office, department and university. I would say, that every time someone is measuring the height somewhere in Germany, it will most certainly need to be the “Normalhöhennull” because it is the national standard since 1992. Because of that not only our authority has this problem, but everyone who wants to measure the height in Germany using Field Maps.

14 Comments
Y_Chau
by

@LaurenceLanglois1 if you select the correct geoid in Leica Zeno Connect app then the MSL heights are transferred to feature Z. The GNSS metadata will always display HAE though. I did this test with Leica FLX100.

Sincerely

Basbo
by

@Y_Chauthank you for your message. What do you mean that the heights are transferred to feature Z?

Is there any attribute showing this information? Or do I need to add POINT_Z with ArcGIS Pro to see this value?

Y_Chau
by

@Basbo hello, Add XY Coordinates (Data Management)—ArcGIS Pro | Documentation

This tool will pull geoid heights from feature geometry and write them to POINT_Z field. Your layer SHOULD be Z enabled.

If you don't have one of the esri partner GNSS devices, then you will get ellipsoidal heights in both metadata and feature geometry. In this case you can do a vertical transformation from ellipsoidal to geoid, provided your geoid is available in the esri supported vertical CS files. You have to install a special CS package to do vertical transformations.

LaurenceLanglois1

My goal is to have this work without any extra steps.  My Zeno Connectpp shows the altitude on the screen. I would think it would easily move that altitude info into a field in field maps. That is not the case.