I've recently been playing a bit with trying to get DEMs working in TG v. 3.2.03.0. On the National Map Viewer, the only format it seems to offer me that has 1/9 arcsecond resolution is IMG. And I can't seem to get those to work. I have gotten some other formats to work. But with IMG, I just get something like this:
[attachimg=1]
With a few of the IMGs I downloaded, I get part of something, a corner with some geometry or something like that, but most of the surface is missing, like this:
[attachimg=2]
I also had that with an IMG file. Changing the displacement factor from 1 to 0.01 (I believe) helped.
Hi,
Try checking the "Replace NODATA values" checkbox and clicking the "Set to Min Height" button.
Regards,
Jo
Actually, I discovered what the problem is. I just apparently didn't know how the National Map Viewer works. I was downloading elevation data for areas for which that kind of data isn't available. I finally selected the overlay that shows availability of 1/9 arcsecond data, and the areas I had defined by drawing a box to download data for aren't covered. I tried an area that is inside the coverage and that worked.
I am surprised that their map viewer allows you to order data for areas for which there is no data of that type, and even sends you a file with nothing in it!
Thanks anyway for your suggestions!