custom utm projection

phxdwlphxdwl Global Mapper UserPosts: 56Trusted User
edited October 2009 in Projection Questions
i am attempting to use a custom utm projection, that places 0,0 at the borders of ut, id, and wy

i loaded it and the cordinates shown in the corrner are not showing that it is using my prj file.

is it just not using the prj file or showing the original utm cordinates

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited October 2009
    I took a look and found the problem. Global Mapper was recognizing the UTM zone from the projection name and using that despite the custom projection definition. I have updated GM to check the parameters to make sure they are a valid UTM projection before assigning it as UTM. I have placed a new build at http://www.globalmapper.com/global_mapper11.zip with the change for you to try. Simply download that file and extract the contents into your existing v11.xx installation folder to give it a try. If you are using the 64-bit v11 version there is a new build at http://www.globalmapper.com/global_mapper11_64bit.zip .

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • Frank2Frank2 Super Moderator Posts: 105
    edited October 2009
    One thing to be aware of though is that many projections are designed to work with numbers in a certain range. False Eastings & Northings are chosen for instance so that none of the numbers in the valid area end up negative. Some projection transforms will fail/crash/give unexpected results when you change things too much. UTM may/may not work correctly with your parameters.
  • phxdwlphxdwl Global Mapper User Posts: 56Trusted User
    edited October 2009
    because im unising v 10 i cant use the fix you did is there any way to make it work in v10?
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited October 2009
    It's not currently possible for me to update v10, but if you edit the PRJ file and just change the projection name where it says 'UTM_ZONE', just rename it to something else, like 'UTM_MOD_ZONE'.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • phxdwlphxdwl Global Mapper User Posts: 56Trusted User
    edited October 2009
    thank you as allways great support.

    in version 11 can i do viewsheds from a poly line insted of points?
    for example i want to do a viewshed from a transmission line alternative.
  • phxdwlphxdwl Global Mapper User Posts: 56Trusted User
    edited October 2009
    thanks for the post frank, typically I would never shift my data like this. but unfortunately 3ds max has a nasty habit of dropping decimal points on numbers to far from zero. when trying to model a structure down to the inch the significant digits are important. so this shift is only applied just before data is exported to 3ds max not to the actual data. thanks again for the post
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited October 2009
    While you can't directly generate view sheds from a selected polyline, you can select that polyline, then right-click and select the Advanced Feature Creation option to create point features from the line vertices, then select those points and right-click to create view sheds from those points, which is basically the same thing.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • Frank2Frank2 Super Moderator Posts: 105
    edited October 2009
    phxdwl:

    OK, I understand the need in your type of situation. A Local Cartesian or Orthographic is often used for that. If it works for you with UTM, I wouldn't bother to change it.
    http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?TopicName=Local_Cartesian_Projection
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