[MetaCRS] Datum Transformation Issues

[Richard Greenwood]

On Wed, Feb 22, 2017 at 10:26 AM, Nick Fordes <nick.fordes at locusview.com>
wrote:

> Hi -
>
> I am using the Proj4js library and am having trouble successfully
> transforming coordindates from ITRF 2008 (EPSG:5332) to NAD83 (2011)
> (EPSG:6317).
>

Are you getting an error or incorrect results? The espg definitions for
5332 and 6317 are the same (see below) but that's not to say they are
correct.

# ITRF2008 <5332> +proj=geocent +ellps=GRS80 +units=m +no_defs  <>
# NAD83(2011) <6317> +proj=geocent +ellps=GRS80 +units=m +no_defs  <>


> I have bee successful in entering coordinates into the following tool and
> generating results for going from WGS83 (EPSG4326) to NAD83 (2011)
> (EPSG:6317), however, there is no transformation applied.
>

"NAD" datums are tied to the North American continental plate, "WGS" datums
are tied to the center of the earth. To get meter or sub-meter accuracy
transformations you need to use a grid shift transform. Is that what you're
looking for when you say that no transformation is applied?




-- 
Richard W. Greenwood, PLS
www.greenwoodmap.com
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