hi everyone I was hoping someone could help? I have been in charge of inspecting GIS program at my job and i want to make sure the points that are laid out are correct. When they inputed them they used northings and eastings from our map contracts but i cant figure out how to convert them to NAD83 so i can make sure that they where placed correctly. I beleave the contract documents are in NAD27 but our GIS is in NAD83. Is their a formula or a web page that would do the ocnversions for me.
ArcGIS can do the conversion, but isn't set up to do individual coordinates. You could convert your points into an XY Event layer, transform or reproject them, and/or convert the layer into a permanent feature class. This workflow has the benefit of allowing you to overlay the points against reference data. If you just want to convert a few values by hand, you can check values in ArcMap on the status bar (in the data frame's coordinate system). Or for a stand-alone program, perhaps CORPSCON would be useful.
How many points are we talking about here? We had a similar change-over in our state years back with many lingering NAD27 reference points out there (necessary for basic digitizing). This may have simply been a function of our state plane coordinate system, but we were able to use some simple math to adjust the coordinates datum when needed. It all depends on how many points and how cumbersome its going to be to input them in a table, or if that's even needed...because if its not its likely going to be simpler to attack it from a different angle.