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Which is a common transformation between NAD 1983 and WGS 1984?
A common transformation in North American data is between NAD 1983 and WGS 1984, such as between the GCS_North_American_1983 and GCS_WGS_1984 geographic coordinate systems. See ESRI Support KnowledgeBase article 24159 for tips on how to determine which transformation to use between NAD 1983 and WGS 1984.
How does a geographic transformation change a datum?
Because geographic coordinate systems contain datums that are based on spheroids, a geographic transformation also changes the underlying spheroid. There are several methods, which have different levels of accuracy and ranges, for transforming between datums.
Is the World Geodetic System 1984 the same as NAD 1983?
When originally defined, North American Datum 1983 (NAD 1983) and World Geodetic System 1984 (WGS 1984) were equivalent. In order to minimize coordinate changes, NAD 1983 is tied to the North American, Pacific (for Hawaii, Guam, etc.), and Marianas tectonic plates.
How big is the semi major axis of WGS 1984?
This axis for WGS 1984 is 6356752.3142 meters, while the semi-major axis both spheroids measures 6378137 meters. Article 18317 What NTv2 geographic transformation grids are supported in ArcGIS Desktop?
How are geographic transformations recorded in the metadata?
When using the Project Tool, the geographic transformation is recorded in the metadata. To learn more about geographic transformation methods, check out: Map Use: Reading and Analysis, 6th edition, by Kimerling, Buckley, Muehrcke and Muehrcke.
How to change NAD to World Geodetic System?
The picture above illustrates a transformation that converts from North American Datum (NAD) 1927 to World Geodetic System (WGS) 1984. When working with geographic transformations, if no mention is made of the direction, an application or tool like ArcMap will handle the directionality automatically.