topic Re: Custom Transformations in Coordinate Reference Systems Questions

Custom Transformations

CaitlinChristenson1 — Tue, 08 Mar 2016 15:53:27 GMT

I just made a custom transformation as a .gtf file. Where/ How do i use this to transform my data? Please let me know thank you

Re: Custom Transformations

AdrianWelsh — Tue, 08 Mar 2016 15:59:51 GMT

This article may help describe what is needed to do:

Create Custom Geographic Transformation—Help | ArcGIS for Desktop

Look under the Usage section.

Re: Custom Transformations

CaitlinChristenson1 — Tue, 08 Mar 2016 21:24:13 GMT

I tried that step and it did not work.

Re: Custom Transformations

AdrianWelsh — Tue, 08 Mar 2016 21:28:56 GMT

Caitlin,

Can you explain what isn't working and if you are getting errors or not?

Re: Custom Transformations

CaitlinChristenson1 — Tue, 08 Mar 2016 22:03:31 GMT

I got an unknown coordinate system layers called Outlet and Tile from someone. I then asked what their projection was suppose to be and it was NAD 1983 UTM Zone 14N so used the define projection tool for both of those layers. I then did the custom geographic transformation tool and did steps according to this 44021 - Transform between NAD 1983 and Minnesota County Coordinate Systems then I used the project tool to get it from NAD 1983 UTM 14N to NAD 1983 HARN Adj stevens feet and used the custom geographic transformation in place of the geographical transformation. Please refer to the picture below. Unless I am setting it up completely wrong. I don't think I got any errors it just wasn't lining up with our data.

Re: Custom Transformations

AdrianWelsh — Tue, 08 Mar 2016 22:59:46 GMT

How far off was your geographic data? Like, where did it put your stuff in relation to where it should have put your stuff?

Re: Custom Transformations

CaitlinChristenson1 — Wed, 09 Mar 2016 14:34:40 GMT

Miles and miles. I couldn't see it in ArcMap

Re: Custom Transformations

AdrianWelsh — Wed, 09 Mar 2016 16:52:02 GMT

If that's the case, then it sounds like something needs to be done with the coordinate system. It seems that it's not matching up with the data. I would first toy around with the different coordinate systems in order to try to get it relatively close to where it needs to be. If it is that far off then sometimes you may need to look at UTM versus lat/long type of systems or maybe zone N versus zone S type of systems (depending on how far off it is). It sounds like this will take some testing to figure out, unfortunately.

Re: Custom Transformations

MelitaKennedy — Thu, 10 Mar 2016 00:27:54 GMT

Caitlin,

Can you post a sample coordinate pair from the original dataset (UTM)? If you add a basemap, does it look like it's overlaying correctly? Or if you change the data frame's display unit to decimal degrees, do they make sense?

Generally, if the output of a Project shows up in a weird place, the original data will too.

Melita