Convert a list of NAD27 Lat/Longs to NAD83 Lat/Longs

[spnclr]

Hello,

We have worked on this for a couple of days and are stuck.  We have a list of locations that given to us in "State Plane. NAD27. Oklahoma South Zone. EPSG: 32025".  We are tasked with converting these Lat/Longs to "State Plane. NAD83. Oklahoma South Zone. EPSG: 32125" and adding the new columns of NAD83 points at the end of the data table.  We have tried several things without success.  If anyone has done this and are willing to share, we would be very appreciative. 

Attached to this message is an Alteryx Workflow file with a sample of made up locations. 

Thank you!

[CoG]

I am not very familiar with these projections, but have you tried the following:

Where the Create Points Tool uses the NAD27 Projection (ESPG: 32025):

And the Spatial Info Tool is configured to output Centroid as X and Y Fields (Long/Lat, respectively) via the NAD83 projection (ESPG: 32125):

I learned something new working on this problem, so thanks for asking the question.

Hope this helps and Happy Solving!

[spnclr]

Hi CoG,

Thank you very much for the attempt.  This is the same process we've tried, and it seems like it works but the NAD83 output is not correct.

We are continuing to try but if anyone else can figure this out, it would be a huge help.  If we find a solution first, we will post.  

Thank you, Alteryx Community!  

[CoG · Accepted solution]

I ran the points through this converter: Transform coordinates - GPS online converter (epsg.io), and found that the outputs did differ between this site and Alteryx (although Alteryx thinks its own calculation is more correct (since distance is 0 between its own output and input). That being said, all of the points are off by 1.2 meters (According to Alteryx) which is quite small. I'm not sure what the cause of the difference is, but I'm curious if the scale of the difference is small enough to be inconsequential. The accuracy of NAD83 is 4 meters as it is.

Check out my response to this very similar post: Projection from NAD27 to NAD83 using Alteryx Spati... - Alteryx Community. 

[spnclr]

Awesome!  Thank you for the help.  I'm just now learning some of the more advanced features.