Local Coordinate

txrplstxrpls Global Mapper UserPosts: 83Trusted User
edited June 2014 in Raster Data
What would you select for a coordinate system that is local (project based) in meters that you want to convert to a feet in a local system in other words the tiff is meters and I want it converted to feet.

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited June 2014
    If you don't care about where it is placed but just the scaling, I would choose Orthographic with meters. Then you can change the units to feet on the Projection tab of the Configuration dialog. If you want it placed correctly and it doesn't have coordinates, use the File->Rectify Imagery menu command or just select to manually rectify it when prompted.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • txrplstxrpls Global Mapper User Posts: 83Trusted User
    edited June 2014
    If you don't care about where it is placed but just the scaling, I would choose Orthographic with meters. Then you can change the units to feet on the Projection tab of the Configuration dialog. If you want it placed correctly and it doesn't have coordinates, use the File->Rectify Imagery menu command or just select to manually rectify it when prompted.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation

    Thanks Mike. What I am doing is using TX State Plane but creating surface/project coordinate scaling by the reciprocal of the average combined scale factor depending on what you want to call them. I then drop of the millions to keep them being confused with TX State Plane. I have to use meter because the Pix4D software has a bug that will only use meters to process an LAS and ortho Tiff in a local system. I want want to get that back to feet so the ortho will open up in C3D in the correct location with the rest of the survey data. I also need to get the LAS into feet so my DTM will be in the correct location. Sorry to be long winded, but you probably know a better approach.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited June 2014
    If you just want to drop the millions off you could change to the same base projection as the TX State Plane, but just change the false easting and northing to subtract off the millions. The LAS should still store the correct georeference when exported from GM, it just won't be TX State Plane anymore but the custom projection with the large false easting/northing.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
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