jlmedfordjlmedford Global Mapper UserPosts: 1
edited June 2007 in Projection Questions
Need some help! I have some Russian Topo of Mongolia that I am georeferencing. The printing on the map is telling me that I have UTM Zone 48 WGS 66. The only two selections for that datum are WGS 84 & WGS 72. It will let me build a new datum, but I don't know the difference or the shift or scale factor between WGS 84 and WGS 66. Is WGS 72 the same as WGS 66? Can You Help? Also I did create a new WGS 66 Datum and did not put in any parameters, it saved it and now I can only over write it and not delete it!



  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited June 2007

    I could not find any transformation parameters from a WGS66 datum to a WGS84 projection. The WGS66 ellipsoid is built in to Global Mapper, so I'd suggest just creating a new custom datum based on the WGS66 ellipsoid with no transformation parameters. The WGS66 ellipsoid is slightly different than the WGS72 ellipsoid.

    To delete custom datums, you need to close Global Mapper, then open the custom_datums.txt file in the Global Mapper installation folder and delete the line with the custom datum that you want to remove.

    Let me know if I can be of further assistance.


    Global Mapper Support
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