Transformation issues between GCS WGS84 and GCS NAD83 using 10.2.1

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02-04-2014 01:59 PM
WhitynOwen
New Contributor
I've experienced some unexpected data shift when projecting between GCS WGS84 and GCS NAD83 using either the default ITRF00 transformation or the NAD_1983_To_WGS_1984_5 transformation. I'm aware that the difference between the same coordinates in each Datum will be up to ~2m on the ground in CONUS.

However, the transformation is consistently NOT applied at all when following the steps described below, even though it is selected from the Transformation drop down list in the Project tool.

Can anyone either confirm my results or point out my error?

Test (Revised):

Start with a point shapefile in GCS WGS84
Delete the .prj file
Use Define Projection tool to redefine to GCS WGS84 in 10.2.1

Add fields (Text, 20char) "Orig_X" and "Orig_Y"
In ArcMap, open table >> Calculate Geometry for each field to retrieve starting coordinates
Close ArcMap

Using Catalog - Toolbox >> Project the shapefile to GCS NAD83 using the default ITRF00 transformation

Add fields (Text, 20char) "GCSn83_X" and "GCSn83_Y" to the new NAD83 dataset
In ArcMap, open table >> Calculate Geometry for each field to retrieve transformed NAD83 coords
In my tests, these values match the Orig_X and Orig_Y coords exactly; i.e. not transformed




Thanks.
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2 Replies
JustinCarasick
New Contributor III
i'll have a look and try your test case. I am having a similar issue in 10.2.1 with regard to replication. I replicate my data from NAD83 to WGS84. it seems at 10.2.1 the "Synchronize" tool is no longer honoring my transformation set in the GP Environment.
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WhitynOwen
New Contributor
UPDATE:

I traced the issue to the .prj definition. In the .prj file, "Degree" was lowercase, i.e. "degree."
In 10.2.1, the transformation is not applied if "Degree" is spelled "degree."
Note that case does not appear to matter in previous versions including 10.2.0.

Also note that the .prj file packaged with 10.2.1 will be read correctly as it contains an upper case "Degree."
I had inadvertently saved a .prj file with the lowercase "degree" to my favorites. Thus when I deleted the .prj and then re-defined it, I used the lowercase "degree" version from my favorites, which then produced the bug.

So, to reproduce the bug, edit any WGS84 .prj to "degree" and the transformation will not be applied when going to NAD83.
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