Hello,
I'm wondering if it is necessary to apply a transformation from CGVD13 to WGS84? I have a large dataset of hydrographic soundings obtained with GCS WGS84 and a reference water surface elevation (WSE) obtained with CGVD13. I need to subtract the WSE from all depth soundings to get a true bed surface elevation. I can't find any references online that provide a simple or straightforward answer.
From what I gather here, Height Reference System Modernization (nrcan.gc.ca), CGVD13 uses the CGG2013a realization which is 'synonymous' (?) with NAD83(CSRS)/ITRF2008 realizations. Then from other sources, WGS84 is 'synonymous' with ITRF2008. So does that make the CGVD13 and WGS84 ellipsoid near equal?
