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I'm using ArcMap 10.3 on Windows 10.

I have a number of .bil and .tif files pertaining to altitude and weather data. I want to open these in ArcMap. When I attempt to add them to the map I get this dialogue box: Box

Can someone walk me through how to use this to open these files in ArcMap?

This is the error that I've encountered trying to do this myself: Box1

Or it throws up a generic "can't open this" error. I would share a screenshot of this but I can't replicate the error.

The goal is to use these data to find the average temperature, slope, etc for a number of points (n=157), so I assume I would need the .bil/.tif to have a spatial referencing system. I'm using the Irish Grid coordinate system.

EDIT I used the Define Projection tool on the files and they did change to Irish Grid (when I right click the feature class go to Properties < Source it does say it's in Irish Grid) - but the data doesn't line up with all my shapefiles in the Irish grid, it's "off in space" just the same as having no coordinate system. I tried this with both file types and the result is the same.

PolyGeo
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rakuenvi
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  • What happens when you click Yes and OK to the two dialog boxes? – Midavalo Aug 09 '16 at 19:16
  • unknown spatial reference is not an error - you need to assign a projection to your images (tif will be tfw) http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?topicname=BIL,_BIP,_and_BSQ_raster_files – Mapperz Aug 09 '16 at 19:17
  • @Midavalo: The same dialogue box appears when I click Yes. The image does appear if I "zoom to" but can't be projected. Are these files meant to have an attribute table? I can't open it when I click Yes and Ok to the boxes. – rakuenvi Aug 09 '16 at 19:19
  • @Mapperz: I can't assign one, which is the issue. If I go to ArcToolbox > Project the file does not appear as an input feature and cannot be projected. – rakuenvi Aug 09 '16 at 19:20
  • If you don't have spatial reference information (possibly should be a .tfw and .blw files with your images) you will need to georeference the images yourself. – Midavalo Aug 09 '16 at 19:28

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Building pyramids will not alter your data in any way, it only speeds up the display of the data as you pan & zoom.

Use the Define Projection tool to indicate what is the current projection/coordinate system of the rasters. The Project tool is for creating a new dataset in a different projection. The source of your raster data should know what projection should be used.

You may need to define the projection before pyramids can be built.

Bjorn
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  • Thanks. As per your answer, I used the define projection tool and it has changed to Irish Grid (when I right click the feature class go to Properties < Source it does say it's in Irish Grid) - but the data doesn't line up with all my shapefiles in the Irish grid, it's "off in space" just the same as having no coordinate system. I tried this with both file types and the result is the same. – rakuenvi Aug 09 '16 at 19:41
  • What I often do with undefined data is add it to an ArcMap project with projected data of known quality, then experiment by setting the Data Frame coordinate system to those commonly used in the region. When your unknown data suddenly lines up, that's probably the coordinate system it is in. – Bjorn Aug 09 '16 at 19:48
  • I'm afraid I don't understand - I've added the undefined data to my current project that contains other data in Irish grid like counties, roads, etc all from the Environmental Protection Agency website (so "known quality"), but it doesn't line up. Does that mean I need to change the coordinate system of all my other data to match whatever one my undefined data works best with? That would ruin weeks of work, as I would need to run my analyses again for the new coordinate system... – rakuenvi Aug 09 '16 at 20:02
  • No, do not change the coordinate system of any good data! Go into the properties of the data frame, select the Coordinate Systems tab, and change the settings there. If you happen to choose the one that your undefined data uses, it will then line up with your defined data. – Bjorn Aug 09 '16 at 20:12
  • Oh ok. That will be extremely tedious as the data could be in any of the coordinate systems as it's from a worldwide dataset (WorldClim)... I might just try looking for another place to get weather and topography data from that has a coordinate system defined. – rakuenvi Aug 09 '16 at 20:23
  • One clue would be the coordinates that appear as you mouse over the data. If it's between [-180,180] N-S & [-90,90] E-W, you can pretty safely assume that it's lat/long based.

    Yes, it would be tedious to try every coordinate system to find the one that works, that's why I said earlier to try the ones that are commonly used in the region.

     – Bjorn Aug 09 '16 at 20:27
  • Thank you - I tried messing around with the data frame's coordinate system but it never lined up... I went ahead and got new datasets for elevation and weather, hopefully they'll be easier to manage. – rakuenvi Aug 10 '16 at 19:32