Is it wrong to temporarily switch layer coordinate systems?

947
3
Jump to solution
08-09-2016 07:33 AM
Highlighted
New Contributor II

I want to temporarily change my layer coordinate system from a state plane to WGS 1984, use the Geometry Calculator to populate  Lat / Long fields, then switch it back to my state plane.

Would this cause any issues?

I've read a number of longer work arounds, but curious if this is an acceptable method.

Thanks in advance

Reply
0 Kudos
1 Solution

Accepted Solutions
Highlighted
MVP Esteemed Contributor

it is fine to temporarily switch, do the calculations, then switch back.  Alternately, you can just use the tool in arctoolbox and specify the coordinate system there.

Add Geometry Attributes—Help | ArcGIS for Desktop

View solution in original post

3 Replies
Highlighted
MVP Esteemed Contributor

it is fine to temporarily switch, do the calculations, then switch back.  Alternately, you can just use the tool in arctoolbox and specify the coordinate system there.

Add Geometry Attributes—Help | ArcGIS for Desktop

View solution in original post

Highlighted
MVP Esteemed Contributor

It's been a while since I've noticed a black SUV with FPPEA ( Federal Projection Protection & Enforcement Agency) emblazoned on the doors.  Pretty sure they are laying low until after November.  Now's a really good time to follow Dans advice and go for it.  But if anyone asks, you heard it from him.  Not me... 

Highlighted
Frequent Contributor II

Specify the coordinate system you want to use in a blank session.

Add the features you want to calculate.  Create your Fields and use the calculate Geometry tool.

Specify to use the coordinate system of the data frame.

If you don't specify the projection before you add the data it will default the data frame to the projection of the data.

You can also specify the data frame projection after you add the data.

However, I don't think you really need to do that.

Using the calculate Geometry tool if you select Decimal Degrees as you units. It will calculate it in Decimal Degrees.  I do this quite often in my State Plane projections and then use the resulting X,Y to generate new features using WGS84