Hello everyone,

I have a very frustrating problem I need help with. I need to georeference points from a Total Station, but unfortunately during set up in the field it was set to the wrong coordinate system. The points were taken by the total station in NAD 1983 Alabama East State Plane, but the trimble points used to gps the control points (and the actual location of the field work) is NAD 1983 UTM 14 North. Is there any way I can still georeference the total station data?

I want to make sure first that I am not going about this in the wrong way: I tried generating the UTM coordinates for the total station points by using one GPS location to determine the UTM coordinate of the "origin" in the total station data, so I could then use that to determine the UTM coordinates for the rest of the points. The arbitrary values assigned to the total station origin were 1000 E and 1000 N. The known point I have GPS data for has a UTM coordinate of (let's say) 634,886.208 E and 3,348,607.547 N (NAD 1983 UTM 14N), and the total station reading for this point was 1030.68223 meters E and 879.26696 meters N of the origin. If I understand this correctly, this means the total station origin UTM coordinates should be 634,855.52577 E and 3,348,728.28004 N (subtract about thirty meters from the GPS UTM easting and add about 120 meters to the UTM northing). This procedure seems like it should give me correct UTM values, but the points are not ending up where they should based on the imagery I have for the area. They are usually 10-20 meters away from where they should be. Is this because the points were taken with the instrument set to the wrong coordinate system? Or am I doing something else wrong?

I also tried georeferencing the data using the spatial adjustment tools in ArcGIS, but I only have two GPS points, so the majority of the points end up very distorted. Any advice about how I could go about determining the real-world positions for these points, or if it's even possible given the coordinate system error when they were taken, would be greatly appreciated.

Thank you!