What datum is my data in

Question

I am collecting location data using high resolution GPS with RTK correction.  The equipment I am using is an arrow gold setup to collect using geoid 18 NAV88/NAD83(2011)

I have three known referenced locations that I have been tracking and we are getting altitude results within 0.1' of the reference and horizontal within 0.3' of reference.  The reference is using NAV88/NAD83(2011)

Being new in all of this, I noticed after a year of collecting data that the datum for my feature is WGS84 Web mercaptor.  If I am understanding things correctly, I should then see an offset of about 1.5 - 2 feet.  And I am not.

Is Suvey123 looking at that data and assuming that it is WGS84, and giving results as if it is?  If Survey123 is doing some kind of data transformation, what is it?

DavidWLane · Answer

I think I figured out CS coordinate system,  dang I can be slow some mornings.

DavidWLane · Answer

Sorry, I am as dense as a rock what does "CS" stand for?

ZenMasterZeke · Answer

I think that AGOL, and possibly Enterprise, S123, etc., display data in Web Mercator, converting on the fly similar to Pro, where layers can have a different cs than the map. This doesn't change the features' actual cs. I'm not an expert on troubleshooting cs's though, so might well be wrong.