Georeferenced Control Points/World File

Craig_Eissler_Iceman

When Georeferencing (DWG CAD data) limited to only 2 Control Points, the alignment is OK, but not great. It automatically produces a World File that I show below.

1. Do the results look odd? They sure don't resemble the ArcGIS Pro Help doc example.

2. And, where values do exist, they do not appear to have anything to do with the Coordinate System ...why?

3. Finally, what do each of these 6 Columns represent? ...The Help doc was confusing to me.

Thanks, CCE

ThomasHoman

Looking at https://pro.arcgis.com/en/pro-app/latest/help/data/cad/world-files-for-cad-data.htm

Line1 - <from-pt1x,from-pt1y,from-pt1z> <space> <to-pt1x,to-pt1y,to-pt1z>
Line2 - <from-pt2x,from-pt2y,from-pt2z> <space> <to-pt2x,to-pt2y,to-pt2z>

where:

from-pt2x - starting x (E) point in cad dwg
from-pt2y - starting y (N) point in cad dwg
from-pt2z - starting z point in cad dwg
<space>
to-pt2x - destination x (E) point in cad dwg
to-pt2y - destination y (N) point in cad dwg
to-pt2z - destination z point in cad dwg

They looks perfectly fine compared to the help example, it's just that your cad dwg started from a different location thus the zeros on the front end and since there was no vertical transformation the z values are zero.

With this information, it appears that the cad drawing was somewhere around 0,0,0 and moved/transformed into the neighborhood of 1240814, 375667, 0 (X,Y,Z)

Something to consider, in most coordinate systems Y equates to north and X equates to east, so does reversing the coordinate make sense for your particular coordinate system 375667, 1240814?

Regards,

Tom

Craig_Eissler_Iceman

Thanks, Tom.

Here's a re-do. The Map View and Reference (Target) data are set to the same projected coordinate system.
The CAD has an Unknown coordinate system.

The Control Point table definitely reflects those projected coordinates, but I still cannot make sense of the coordinates in the associated and, automatically created, World file. ..Any clue?

Also: I know what a PRJ file is, and noticed that was automatically created as well, and was assigned the aforementioned projected coordinate system. ...So, does it just take this from the Map coordinate system?

By the way: I also tried assigning a coordinate system FIRST to the CAD DWG data to see if that changed anything. The Control Point table looked the same but the World file had completely different values, and still not the real projected coordinates.