Issues with a particular DXF file

Hunter GeophysicsHunter Geophysics Global Mapper UserPosts: 75Trusted User
edited August 2014 in Technical Support
A1 grid only.gmptrack.zip

Hi Mike, and others. :)

Having quite a bit of trouble with a DXF file and was hoping you'd be able to help, please.

I have attached two files:


A GMP file, with a single area.
A DXF file, which should contain a few dozen parallel lines (can't remember how many). The lines should be running roughly NNE-SSW, and should be roughly within the area in the GMP file.

I've never used CAD before so don't know what projection/datum it should be in.

The supplier says it should be in the same projection and datum as my GMP data, but selecting that makes it project some 12,000km to the south of the area in the GMP.

I would appreciate your help in trying to figure out how to get this to project properly, please.

Thank you in advance for your help, as always. :)

Dave

Comments

  • Hunter GeophysicsHunter Geophysics Global Mapper User Posts: 75Trusted User
    edited August 2014
    By the way, the parallel lines should be about 25cm apart.

    Here's a screenshot from the program that created the DXF, showing the lines (I also note the coordinates seem to be in some other system...?)


    Snap 2014-08-12 at 21.55.36.png
  • Josie_BMGJosie_BMG Global Mapper User Posts: 71
    edited August 2014
    Hi Hunter Geophysics, I have looked at the vertices of the line features in the DXF file, since the vertices are located very close to the point of origin, it does not appear that this data is projected. You will need to either go back to the data source or manually rectify the lines to a known location.

    Let me know if you get any more information from the source of the data or if you have any further questions.

    Regards,
    Josie
  • Hunter GeophysicsHunter Geophysics Global Mapper User Posts: 75Trusted User
    edited August 2014
    Hi Josie,

    Thanks for that advice; I appreciate it.

    "You will need to either go back to the data source or manually rectify the lines to a known location."

    Sorry, I don't quite understand... what do I need to find out from the data source? And how would I manually rectify the lines?


    Thanks again,
    David
  • Josie_BMGJosie_BMG Global Mapper User Posts: 71
    edited August 2014
    Hi David, Going back to the source of the data would be the preferred option. The screenshot of the application does show similar grid coordinates to the location of your polygon feature, so it may just be an export setting that they need to adjust to add the proper x and y coordinates. Alternatively, you can move the lines to the area feature location. Click the full view button, right click on the DXF layer in the Overlay Control Center, choose Select All Features in Selected Layer with Digitizer Tool, right click on the map and choose MOVE - Move Selected Features. You can then left click on the lines and drag them to the area feature. Because the lines are located at the origin of the map they are very far from the Area Feature, you will need to go through this step several times to get close enough to fine tune the location. You will need to have a known coordinate for one of the vertices in order to move them to an accurate location.


    Hope this helps!
    -Josie
Sign In or Register to comment.