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This is a related question to this one asked ~3 years ago:

Geographic Transformations in Alaska Between NAD83 and WGS84

We are currently on ArcGIS Desktop 10.4.1

What is the best geographic transformation for Alaska to go from NAD83 (NSRS2007) to WGS84?

NAD_1983_NSRS2007_To_WGS_1984_1
NAD_1983_CORS96_To_NAD_1983_NSRS2007 + WGS_1984_(ITRF00)_To_NAD_1983_CORS96
NAD_1983_NSRS2007_To_NAD_1983_2011 + WGS_1984_(ITRF00)_To_NAD_1983_2011
NAD_1983_NSRS2007_To_NAD_1983_2011 + WGS_1984_(ITRF08)_To_NAD_1983_2011

The parameters for the transformations can be found in this Esri pdf: http://desktop.arcgis.com/en/arcmap/latest/map/projections/pdf/geographic_transformations.pdf

NAD_1983_NSRS2007_To_WGS_1984_1, NAD_1983_CORS96_To_NAD_1983_NSRS2007, and NAD_1983_NSRS2007_To_NAD_1983_2011 are all null transformations, so they are changing the datum definition only. The latitude and longitude values remain the same.

Out of the four available Esri transformations "chains" I think best option is to use NAD_1983_CORS96_To_NAD_1983_NSRS2007 + WGS_1984_(ITRF00)_To_NAD_1983_CORS96 or NAD_1983_NSRS2007_To_NAD_1983_2011 + WGS_1984_(ITRF00)_To_NAD_1983_2011 (they are equivalent).

NAD_1983_NSRS2007_To_NAD_1983_2011 + WGS_1984_(ITRF08)_To_NAD_1983_2011 is not acceptable because maximum latitude of WGS_1984_(ITRF08)_To_NAD_1983_2011 is 66.67 degrees north. This puts some of our project data on North Slope outside of its use area.

NAD_1983_NSRS2007_To_WGS_1984_1 is a null transformation (bookkeeping) so it can be rejected as well.

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  • As per the Tour there should be only one question asked per question.
    – PolyGeo ♦
    May 2, 2017 at 23:41
  • @PolyGeo I have cut out the second part of it as requested. Can you please take it off hold?
    – fallingdog
    May 3, 2017 at 0:04
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    This is a case where specifying a software version would make a difference. We added GEOCON v1 files at 10.4, so NAD_1983_NSRS2007_To_2011_GEOCON11_Alaska + WGS_1984_(ITRF08)_To_NAD_1983_2011. There's a separate data install for the GEOCON files (plus some vertical tfm files).
    – mkennedy
    May 3, 2017 at 0:15
  • We are on 10.4.1. i edited the question as well
    – fallingdog
    May 3, 2017 at 16:50

1 Answer 1

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Right click on your NAD1983 data to see its properties (in ArcCatalog) If raster click edit under Spatial Reference XY and create a CUSTOM GCS_WGS_1980. Choose GCS_WGS_1980, change your central meridian to -180, click ok, click apply and it is done. Now whenever you need it you have a custom reference system. The key is changing the central meridian for Alaska. For NAD1983 the 180 is positive. This works for Albers, etc. All will change Alaska to look like Alaska with all the islands present and no inset needed. If not a raster right click the layer for properties and do the same. THis is a geographic tranformation.

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  • Hi Evelyn. Welcome to Geographic Information Systems. Please take the tour so you can find out more about how this site works. Your answer does not appear to apply to the question which asked about transformations. You also appear to have a mix between WGS 1984 and GRS 1980.
    – mkennedy
    Mar 13, 2019 at 21:22

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