+ Reply to Thread
Results 1 to 2 of 2

Thread: Reprojecting State Plane & GCS_GRS_1980 to WGS_1984_Web_Mercator_Auxiliary_Sphere

  1. #1
    Brian Durham
    Join Date
    Jul 2010
    Posts
    3
    Points
    0
    Answers Provided
    0


    0

    Default Reprojecting State Plane & GCS_GRS_1980 to WGS_1984_Web_Mercator_Auxiliary_Sphere

    We are attempting to reproject several raster and vector datasets from GCS_GRS_1980 to WGS_1984_Web_Mercator_Auxiliary_Sphere. I have tried a several different transformations but each time there is a noticeable shift in the data. Does anyone know the correct transformation to use? Our data is mostly in the SE United States, mainly Georgia, South Carolina, & North Carolina. We also have a few datasets that span the entire USA.

    I'm having the same problem determining the correct transformation from state plane (GA FT, SC Int FT, & NC FT) to web mercator. Any ideas?

    Thank you very much in advance!
    Brian

  2. #2
    Melita Kennedy

    Join Date
    Nov 2009
    Posts
    1,816
    Points
    521
    Answers Provided
    75


    0

    Default Re: Reprojecting State Plane & GCS_GRS_1980 to WGS_1984_Web_Mercator_Auxiliary_Sphere

    Quote Originally Posted by brianddurham View Post
    We are attempting to reproject several raster and vector datasets from GCS_GRS_1980 to WGS_1984_Web_Mercator_Auxiliary_Sphere. I have tried a several different transformations but each time there is a noticeable shift in the data. Does anyone know the correct transformation to use? Our data is mostly in the SE United States, mainly Georgia, South Carolina, & North Carolina. We also have a few datasets that span the entire USA.

    I'm having the same problem determining the correct transformation from state plane (GA FT, SC Int FT, & NC FT) to web mercator. Any ideas?

    Thank you very much in advance!
    Brian
    Hi Brian,

    I assume, because they're state plane, that the geographic coordinate systems are either NAD 1983 or NAD 1983 HARN (or both). Any NAD83 / WGS84 transformation should do minimal to no shifting, depending on which one is used. At worst, in that part of the country, they should differ by no more than a meter. Are you seeing shifts larger than that?

    NAD_1983_To_WGS_1984_1 is a null transformation (parameters are zeroes). It assumes NAD 1983 and WGS 1984 are equivalent. That isn't true any more, so a more current transformation, NAD_1983_To_WGS_1984_5, does try to compensate for the current differences.

    NAD_1983_HARN_To_WGS_1984 is another null transformation.
    WGS_1984_(ITRF00)_To_NAD_1983_HARN is similar to NAD_1983_To_WGS_1984_5.

    Melita
    Melita Kennedy
    Sr. Esri Product Engineer

+ Reply to Thread

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts