Ind Zone

smilesmile Global Mapper UserPosts: 171Trusted User
edited October 2007 in Projection Questions
I have checked the new Ind Yard linear unit introduced in a recent build. It is near perfect , once we select the required zone and as false Eastings and northings are fixed , there is a very minor difference once we create a point same as that of origin ( say 26n 90 e in IIB) in digitizer tool. It matches perfectly in meters and in Ind yard a very minor change may have to be done in the linear unit conversion taken to exactly show 3000000 indyds easting and 1000000 indyd northing). This is reqd just for the grid only and projection works fine.


Thanks

Smile

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited October 2007
    How large is the difference that you are seeing? The definition of an Indian Yard has actually changed very slightly several times over the last hundred years, so depending on what conversion factor you use you will get slightly different results. Global Mapper is using the conversion factor of one Indian Yard is equal to 0.914398530744441 meters. This was the most recent conversion factor from EPSG.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • smilesmile Global Mapper User Posts: 171Trusted User
    edited October 2007
    The difference is very minor .

    Easting - 3000000 ind yard - Actual 2999999.8999 - diff 0.101

    northing -1000000 -999999.966 -diff -0.034

    Can safely be ignored?

    Thanks

    smile
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited October 2007
    I'd say that you can safely ignore those differences. They are likely due to a slightly different Indian Yard definition being used. Since the differences are on the order of just a few centimeters, you should be fine.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
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