Reprojection from UTM to geographic

prabhakarprabhakar Global Mapper UserPosts: 2
edited April 2008 in Raster Data
Good day,

I am new to this images.Can I change the utm projected ,wgs-84 datum raster in to geographic(lat/long) without any changing datum and planer units.

Regards,
Prabhakar

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited November 2007
    You can reproject your UTM data to Geographic simply by going to the Projection tab of the Configuration dialog and changing the projection to Geographic after loading the data. While you can keep the datum the safe, you do have to change planar units as UTM uses linear units like meters or feet while Geographic uses angular units like arc degrees.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • kartoone76kartoone76 Global Mapper User Posts: 38Trusted User
    edited April 2008
    Is there any way to automate this procedure? I can't find anything in the scripting language that allows you to do this reprojection automatically. You have to manually define your projection, or you have to save the current projection -- but how can you have a script automatically reproject to UTM (the reverse direction of the original poster's message)? Thanks in advance... Brian
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited April 2008
    You can easily change the projection in a script file using the LOAD_PROJECTION command. It can use either a projection that was defined in the script using the DEFINE_PROJ command or load one from a file. Here is some example code to define a Geographic projection and load it:

    DEFINE_PROJ PROJ_NAME="GEO_NAD83"
    Projection GEOGRAPHIC
    Datum NAD83
    Zunits NO
    Units DD
    Xshift 0.000000
    Yshift 0.000000
    Parameters
    END_DEFINE_PROJ
    LOAD_PROJECTION PROJ_NAME="GEO_NAD83"

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • kartoone76kartoone76 Global Mapper User Posts: 38Trusted User
    edited April 2008
    Thanks for the quick reply - but the project you gave would convert to geographic. How would I convert to UTM? Doesn't that depend on the lat/lon bounds of the currently loaded data? Wouldn't that determine which "UTM zone", easting, northing, degree, etc... that goes inside the projection? Does this need to be calculated outside of global mapper or is there a generic UTM projection that can be defined? Thanks again, Brian
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited April 2008
    Brian,

    Sorry, I didn't read close enough. While there is not a way in the script to define a UTM projection that automatically chooses the most appropriate zone for the loaded data, you can do this in the File->Batch Convert/Reproject menu command. With that when you select a new projection to use, select a UTM projection and in the zone box choose the option to automatically choose the best zone. This should do what you are after.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
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