GEOTRANS is an application program which allows you to easily convert geographic coordinates among a wide variety of coordinate systems, map projections, and datums. GEOTRANS runs in Microsoft Windows (95 and NT) and UNIX Motif environments. Developed by the United States National Imagery and Mapping Agency




    Using GeoTrans for large files

    Perseverance pays off. We got our GeoTrans data file to convert (just renamed it) and sorted through the intricacies of the software, but found it really handy. It's just saved us likely 3 days of hand datum conversions of about 3300 sheep and goat locations. Thanks for the tips. If you decide to download it and give it a whirl, I've attached the steps for large file conversion (it took quite a while to work out the bugs, but it's very simple). This may have some applications to the wildlife crowd with regards to old paper location data. Thanks again Salut!
    -- Todd Powell - 30 July 2003
    For large spreadsheets of locations such as in excel, you need to convert the excel file into a .dat file. This is done by saving as a .txt (tab delimited) file, then rename the file suffix as a .dat from a .txt. (may have to go into your computers control panel and select folder options/view/show known file extensions box). In the excel file, before saving, the data must be grouped into one column, and this can be done by writing the formula “=a1&”, “&b1 for all the columns to group up so your resulting column looks like 11, N, 337200, 5996700 Delete all other columns and make sure that the worksheet you’re using is the first one on the worksheet order.


    Setting up the file

    in UTM data there needs to be a setup that looks like this:
    11, N, 337200, 5996700
    (zone, north, easting, northing) Each number/letter needs to be separated by a comma and at least one space no paranthesis are able to be used. Example:


    COORDINATES: Universal Transverse Mercator (UTM)
    11, N, 337200, 5996700
    11, N, 340000, 5994700
    11, N, 337300, 5996500
    11, N, 337200, 5996500
    11, N, 337200, 5995900
    11, N, 337200, 5996400
    11, N, 337100, 5996700
    11, N, 337000, 5995800
    11, N, 337300, 5996500
    11, N, 337200, 5996700
    11, N, 340500, 5992500
    11, N, 341200, 5992400
    11, N, 337000, 5996900

    The input header (very key) can be created by selecting an existing file (several available from the examples in the geotrans program file) and then select the output file with the parameters you’d like for your header (ex NAD83, UTM, zone#). Paste this to the top of your .dat file



    the conversion

    Open GeoTrans and select open file, and select your .dat file to be your input file

    Select your output parameters for what you would like it to become (ex: NAD83, UTM, Zone#), and name a file for it when asked

    click through the instructions, it will display results and errors

    Open the .dat output file in excel, and go through the wizard to select the columns of easting and northing as you’d like and finish

    Now you can convert your new excel file into a text file, then in ArcView create an event theme in a view to bring in the table, then reproject it into the standard projection using avtools.

    For more complete GeoTrans instructions see GeoTrans User manual ({install_dir}/geotrans2/docs/user.doc)

    -- Todd Powell - 30 Jul 2003





    TopicCategory HowTo



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