I realize there are other posts on this topic but I'm not understanding the logic of the consensus so I'm hoping that someone can enlighten me.
I'm using a Trimble Geo7X GPS unit and post-processing the data using the base station positions from Trimble's base station list. Therefore, I am confident that my data is in a newer realization of WGS84 which is essentially equivalent to ITRF00. Following post-processing I export my data from Pathfinder Office to ArcGIS keeping it in the WGS84 datum. All of my GIS map documents and data are in NAD83(1986).
I understand that:
NAD83(1986) = original WGS84
NAD(1986) <> current WGS84/ITRF00
In ArcGIS, I either let the program reproject my GPS data "on the fly" or reproject to NAD83(1986). The consensus seems to be that no datum transformation/shift should be applied in this conversion. If this is correct, can anyone explain why? If NAD(1986)<>current WGS84/ITRF00 how is a datum shift not needed?