Z Values Incorrect after Projecting WGS to State Plane

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09-01-2018 10:46 AM
MatthewMcCloskey1
New Contributor

Hey all,

I use the project tool to project shapefiles that are in WGS to a state plane coordinate system. After running the tool my Z values remain in meters and after converting them to international feet they are still incorrect. They are around 200 feet lower than they should be. In the project tool the vertical checkbox is always disabled (greyed out), which I assume would fix my problem. I was wondering if anyone has had this issue before and knows of a method to obtain the correct Z values. 

Thanks

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3 Replies
DanPatterson_Retired
MVP Esteemed Contributor

what are some example values? and how did you convert the z-values?

Project—Data Management toolbox | ArcGIS Desktop 

An as for the vertical transformation, it is disabled if the file doesn't have one defined.

To perform a vertical transformation, check the optional Vertical parameter on the dialog. By default, the Vertical parameter is disabled and is only enabled when the input and output coordinate systems have Vertical Coordinate System, and the input feature class coordinates have Z values. Also, additional data (Coordinate Systems Data) setup needs to be installed on the system.

so you might have to define the projection assuming you have z-enabled data in order to get the z values changed

VERTICALApplies the transformation specified in Geographic Transformation parameter. Project tool transforms X, Y, and Z values of geometry coordinates.

Maybe this will get you started to see if the files were defined correctly in the first place and whether the features are Polygon/Polyline/Point-Z for the Shape field

MatthewMcCloskey1
New Contributor

Thanks for the response. I am using a program from Trimble called Terraflex. It is collecting data in WGS84. The elevations I am getting are height above ellipsoid. This is where the issue arises. I also use a GPS data collector that collects in State Plane and uses a geoid as reference for elevations. This is what I would like to transform my Terraflex data to. In arcmap I project my terraflex data to state plane, however the Z values don't change.

The checkbox for vertical transformation in the project tool is still disabled. My input and output coordinate systems are both defined, both have vertical coordinate systems and the input data has Z values. As far as "additional data (coordinate systems data) needs to be installed on the system", I am not exactly sure what this means. Could this be what is holding me up? Any guidance here would be greatly appreciated.

I collect only points with my GPS receiver, however, with Terraflex I collect point, line, and polygon features. Again, thanks for the response. 

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TiffanyPuett
Occasional Contributor II

Hi Matt,

If you use the free Terraflex plugin for ArcMap and author your projects from ArcMap, then you can configure the z to be based on MSL/Geoid when checking the data back in.

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