I don't think I'm understanding how the wgs84 to nad83 tranformations work. I'm using ArcMap/ArcPad 10.
From a Gnss-enabled personal geodatabase my ArcPad project properties are:
- Projection = NAD_1983_StatePlane_South_Dakota_South_FIPS_4002
- GPS Datum = D_WGS_1984
- Datum Transformation = NAD_1983_To_WGS_1984_5
I post process thru Trimble GPS Analyst using the "reference positon from base provider" option.
Am I in the State Plane NAD83(1986) realization or a newer realization of NAD83(Harn) or (Cors96)? The transformations differnces beteween the NAD_1983_To_WGS_1984_1 and NAD_1983_To_WGS_1984_5 options confuse me. Wasn't sure if the _1 trans keeps everything in the NAD83(86) version and the _5 transformation places me in the later versions (Harn...Cors96)? I check into published S. Dakota State Plane HARN control fairly well (about a half foot), which is about as accurate as our Geo XH can get. I need to be on the State Plane NAD 83(Harn) system, so I may need to re-project my data and start using a _HARN transformation. Just need to figure out where I'm starting from first.
Any help is appreciated. Thanks, Todd
