WGS84 transformations

[sambagis]

Hi all. 
Im working with data from Hawaii where the geographic reference system WGS84 is problematic.  Does any one know what realization of WGS84 agisoft is using in its basic format??  There are no options for choosing any of the ITFR realizations and my GCP data is all in ITFR00. 

Stephen

[GPC]

New WGS84 realizations are coincident to ITRF realizations to within 10cm, older pre-95) are within a meter. Assuming they are using anyn modern realization, transformation parameters don't even exist, they're assumed to be identical.

All that said, the error caused by using a 25 year old realization is far, far less than the error of auntonomous GPS or drone grade GPS.

What problem are you trying to solve exactly?

[sambagis]

The problem Im having is that when I am exporting data from Agisoft in a projected format the data is off by 1.5m from the original GCP data when viewed in an outside GIS (arcgis 10.x).  The only thing I can figure is that agisoft is assuming a different realization than what was actually used in post processing the GCP points.   In this case ITFR00 was used but it seems like agisoft assumes maybe the most recent realization or either ITFR08 or ITFR14.   The result again is that Im getting 1.5 meters of error just from transformation errors which is in excess of what I need to produce.  I think the major issue is that Hawaii (pacific plate) in comparison to the rest of the US is moving quite quickly every year making these different realizations more important.  Maybe Im completely confused.  Im not a geodesy guy and this stuff gets relatively confusing.   

[Alexey Pasumansky]

Hello Stephen,

If you are speaking about WGS84 (EPSG::4326), then the system parameters are defined according to the information from EPSG registry: http://epsg-registry.org/?display=entity&urn=urn:ogc:def:crs:EPSG::4326

In case you are exporting the results in another system (but the model is referenced in WGS84), you can set up the custom transformation parameters using "Datum Transformation Settings" dialog.
Alternatively, if necessary, create custom geographic coordinate system based on  International Terrestrial Reference Frame 2000 geodetic datum.