I have a large raster layer with wind speed values assigned to each cell. I also have point data that displays locations where wind farms have been constructed. I would like to add the raster values to the wind farm location data. The goal is to figure out when each wind farm was built over each wind speed value. Any ideas?

1 Answer 1


If you have the Spatial Analyst extension, you can use the Extract Values to Points geoprocessing tool to do this very easily.

If you have multiple rasters for which you want to perform this extraction, you can use the Extract Multi Values to Points geoprocessing tool.

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    I've used the Extract Values to Points tool but it keeps assigning the "RASTERVALU" as -9999 for every location. I created my wind speed value raster using matlab. Each pixel has a color value that has been assigned a number. I'm worried that this is causing the tool you mentioned to fail.
    – Jessica
    Jul 2, 2012 at 21:55
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    A RASTERVALU of -9999 indicates placeholder data, meaning the raster data does not properly underlie your point data. Have you visually confirmed using the Identify tool in ArcMap that your raster data directly underlie your points? If not, one of your datasets probably has a projection issue.
    – dmahr
    Jul 2, 2012 at 23:11
  • Check your spatial reference system.
    – Tomek
    Jul 3, 2012 at 5:23
  • I georeferenced using Albers Equal Area Conic projection, which is what the original map was projected in. Once the values were added I needed to project using WGS 1983. I've used the identity tool to confirm each cell contains the correct value. The mouse shows the correct lat/long. Are there typically issues when you georeference to a base map using one projection then change to another?
    – Jessica
    Jul 3, 2012 at 13:34
  • And - the wind raster data says there isn't a defined spatial reference system.
    – Jessica
    Jul 3, 2012 at 13:36

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