I'm using ArcMap 10.3 on Windows 10 and I have the 3D analyst, ArcScan, Geo-statistical analyst, network analyst, publisher, schematics, spatial analyst and tracking analyst extensions.
I have a number of .tif files from ASTER and I need to get a Digital Elevation Model (DEM) of Ireland from them. The end goal is to get the altitude and slope for a number of points across Ireland. Here is a screenshot of these images in ArcMap: These files are in a different coordinate system to everything else that I have - I have read that it's best to project them to the correct coordinate system after I change them to raster. Is this the correct thing to do? Or should I project them first?
I've used 'Mosaic to new raster' to try and bring these images together into something I can use. I had a value of 1 in the number of bands and selected 16 bit unsigned. This did not work. Here is an image of the result: Am I on the right track with mosaic to new raster and just made a mistake, or is this not the way to go about this?
I have tried to project these tifs to the Irish Grid coordinate system (Project Raster), like the rest of my data. However, this doesn't seem to work - what's going on here?
in terms of trying to get the slope, I have been using the spatial analyst tool Slope - every time I use it I get this error, why?
Summary: What are the steps I need to take to use these .tif files to obtain altitude and slope?