Custom projections

DustyRobinsonDustyRobinson Global Mapper UserPosts: 114Trusted User
edited October 2007 in Projection Questions
I would like to add a custom projection for the Minnesota County Coordinate system. There is a website that details all of the information for the conversion, and there is a program called MnCon to perform manual conversions on points. I am trying to set up GlobalMapper so it can perform the conversions instead.

How do I go about doing this?

Website:
http://www.olmweb.dot.state.mn.us/tech/Projections.htm

MnCon:
http://www.olmweb.dot.state.mn.us/lis/software/MnCon.html

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited October 2007
    You can create Minnesota County Coordinate System projections in a couple of steps. First of all, since each county seems to have its own custom ellipsoid, you'll need to create a new datum based on a custom ellipsoid with the necessary parameters. You can do this from the Add Datum button on the Projection Selection dialog.

    Once you have that created for the county, then select the Lambert Conformal Conic (or Transverse Mercator if using one of those counties) projection and input the parameters needed for the county that you are working with. Those parameters are listed on the web site that you listed under the title "Parameters for NAD83 Lambert Conformal Conic County Zones".

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • DustyRobinsonDustyRobinson Global Mapper User Posts: 114Trusted User
    edited October 2007
    When creating the new Datum, which datum transformation method should I use, and where do I get the values for the shift and rotation?
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited October 2007
    Use the 3-parameter transformation and keep all transformation parameters at 0 (the defaults). This will basically generate a NAD83-like datum based on a custom ellipsoid for the county, which is what you want.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • kotikkotik Global Mapper User Posts: 1
    edited October 2007
    How can I pue Estonian coordynate system ("L-EST97 (EUREF89)", 3, 115, 7, 24, 57.51755393056, 58, 59.33333333, 500000, 6375000 ) into Global Mapper.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited October 2007
    The L-EST97 projection is a Lambert Conformal Conic projection with the following parameters:

    Origin Latitude: 57.51755393056
    Central Meridian: 24
    First Standard Parallel: 58
    Second Standard Parallel: 59.333333333
    False Easting: 500000
    False Northing: 6375000

    For the datum choose either ETRS89 or WGS84.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • Hello,
    I would like to add a custom projection for Costa Rica, CRTM 05 proyections. What parameters must I introduced in the software? and how must I performed this action, step by step?

    How do I go about doing this?

    Thank you very much, Cesar
  • partjohnnerpartjohnner Global Mapper User Posts: 16Trusted User
    Is there any built-in version of the NAD83 datum which has an embedded "Clarke 1866" spheroid? If not, what parameters do I need to enter if defining a new datum ("Create New Datum") which would associate the Clarke 1866 spheriod with the otherwise normal parameters of NAD83?  The reason I am asking this is that I am trying to sync GIS data with a data set that was built with the following parameters:

      <entry name='UTMZone12NorthNAD27_HillCountyMT'>
        <structure type='ProjectionUTM'>
          <entry name='datum'>
            <value>NAD83</value>
          </entry>
          <entry name='ellipsoid'>
            <value>Clarke 1866</value>
          </entry>
           <entry name='name'>
            <value>UTMZone12NorthNAD27_HillCountyMT</value>
          </entry>
          <entry name='originLatitude'>
            <value>0</value>
          </entry>
          <entry name='originLongitude'>
            <value>-111</value>
          </entry>
          <entry name='originX'>
            <value>500067.0561320803</value>
          </entry>
          <entry name='originY'>
            <value>6.096012192024385</value>
          </entry>
          <entry name='scaleReduction'>
            <value>0.9996</value>
          </entry>
        </structure>
      </entry>

    As far as I can tell, this specification seems to be using all of the components of the NAD83 datum except for the older spheroid/ellipsoid.  In a custom datum pictured, I am not having luck only specifying the Ellipsoid as "Clarke 1866" -- there is probably something else I need to do to "recreate" the fundamentals of the NAD83 datum.

    Any assistance would be appreciated.

    John
  • kbelliskbellis Global Mapper User Posts: 404Trusted User
    I was thinking about building a globe and was wondering what the best projection might be for its construction. One of the projections I'm considering is an interrupted sinusoidal projection. 

    Is it possible to create an interrupted sinusoidal, 12 gore custom projection in Global Mapper?



    Is it possible to create an interrupted sinusoidal, staggered 12 gore custom projection in Global Mapper?



    Is it also possible to vary the number of gores beyond 12, to say for example 30?

    If it's possible to define any or all of the above described custom projections in Global Mapper, what must I do?

    If there's a better projection to consider for building a globe, please let me know.


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