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I have loaded a raster map that uses WGS 84. I want to locate stations/points on this map by using lat/long coordinated from an online map that uses NAD83.

Can I just copy and paste the lat/long coordinates from the online map into the XYtool in arcmap? Does the XY tool directly convert the lat/long to the correct decimal degree position on the map?

I tried a few samples, the stations look to be in proper positions but I am not sure because the difference in WGS84 and NAD83.

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  • What kind of accuracy do you need? What's the cell size of the raster? Current NAD83 and WGS84 differ by about 1-2 meters. If it doesn't matter, don't worry about transforming.
    – mkennedy
    Jun 10, 2016 at 16:44

1 Answer 1

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Here's What you have to do :

    1. Set ArcMAP to NAD83.
    2. Load your XY data.
    3. Export them to a Shapefile.
    4. Project your Shapefile to wgs84 using the "Project" tool in Data managements toolbox.
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  • The excel files contain lat/long coordinates that uses NAD83, but I have a base map that uses WGS84. After loading the XY Data, the default GCS is WGS84, do I leave it as it is or change to NAD83 (the original lat/long coods). Currently what I did is load the excel file with the lat/long cords from NAD83, in arcmap the default is WGS84 is left untouched. Jun 10, 2016 at 14:18
  • Change it to NAD83 before adding the data, after you finish the procedure, you can go back to wgs84. Jun 10, 2016 at 14:37
  • just to be clear, when I have added the xy data and specified x and y field, I need to edit the coordinate system of input cordinates to NAD83? and then create the shapefile in wgs84? Jun 10, 2016 at 14:50
  • create the shapefile in NAD83 and then Project it Jun 10, 2016 at 14:58
  • So it worked ? still have a problem? if everything is clear enough now, you can mark the answer. Jun 11, 2016 at 19:05

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