topic Re: Which Spatial Adjustment Method? in CAD/GIS Data Integration Questions

Which Spatial Adjustment Method?

Oliver_Burdekin — Thu, 11 Apr 2019 08:35:25 GMT

I have a CAD drawing with no world file or projection associated. I do have grid lines included in the drawing. I am using the spatial adjustment tool to relocate the drawing as when brough into Arc the coordinates are based on the CAD file (nonsensical in a geographic sense). The spatial adjustment tool offers three options for tranformations:

Affine
Similarity
Projective

Having read the docs it strikes me projective would be most appropriate (maintains shapes) but would like to know if this is suitable.

Re: Which Spatial Adjustment Method?

DanPatterson_Retired — Thu, 11 Apr 2019 09:07:10 GMT

Affine, if you just have a shift, rotation and equal scaling in the X, Y direction.. In other words, you just want to move the data to a new location

Re: Which Spatial Adjustment Method?

Oliver_Burdekin — Thu, 11 Apr 2019 09:21:39 GMT

Thanks Dan. In what use cases would the other two suitable? I'm trying all three with these particular data just to get a better feel for the differences.

Re: Which Spatial Adjustment Method?

AdrianWelsh — Tue, 16 Apr 2019 16:49:13 GMT

Oliver, in your own testing, what have you found with these different adjustments?