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I am a bit new to ArcGIS and have run into a snag.
I have a series of points in a shapefile that only have x and y coordinates. Additionally I have a series of other points in a separate shapefile that have x, y, and z coordinates. I have added both to a map and have generated contours from the latter of the two files.
My question is: Is it possible to determine the elevations of the points in the first shapefile based on the second shapefile and contours and if so how?
Assuming that the 3D analyst Extension is available, here is how I would solve the problem:
Using the shapefile containing the heights, I would interpolate and create a DEM. There are many tools for this, such as IDW, Spline and Trend, but I would suggest that you use Topo to Raster tool. In My experience, this produces the most realistic output amongst all the tools.
Once you have the DEM raster, use the Extract Values to Points tool, to get the Z values for the input points(the shapefile having only x & y)
If you have access to the 3D Analyst extension, you could convert your contour shapefile to a TIN and then drape the 2D shapefile over it. You can then interpolate the z coordinates using the Interpolate Shape tool (also in 3D Analyst).
This PDF will walk you through creating the TIN from the contours and also the draping part. The part you want begins on pg. 6 of the PDF file.
In addition, this link provides background on the Interpolate Shape tool.
Hope this helps!!
