FalconView (#1) - Importing elevation data into FalconView (#251) - Message List
I used EarthExplorer? to download 0.3 arc second elevation data, but I can't figure out how to get it into a format that FalconView can read. It appears that the bulk of the data is in a file named like "77650578\77650578\w001001.adf" along with about a dozen other sidecar files. What's the process for converting this?
The only topographic data that FalconView reads is DTED, which is a standard primarily used my the military. I was able to convert 1/3 arc-second NED data to DTED3 and bring it in to FalconView using the following steps:
- I downloaded the data from USGS in ArcGrid format. I downloaded a one degree by one degree rectangle since this is how DTED usually comes.
- I used MicroDEM with the FWTools option to convert the ArcGrid topo data to a DTED3 tile. It took some fooling with MicroDEM to get the right options. As I recall, I had to select the DTED3 option, had to constrain the export to the proper lat / lon square, and had to select the option to force one degree cells.
- I added the DTED3 tile to the proper place in my map data folder. I then used the map data manager to do a "data check" on that folder so that FalconView would catalog the new data.
After I did all of the above, I could generate contours using the higher-resolution DTED3, and I could hover over points to get the elevation (see the attachment to this discussion for the screen capture).
Generating contours was very slow and even crashed (!) FalconView if I made the spacing too close. I suspect that generating close contours for a relatively small area is not a common use case. Also, I couldn't get the shaded topographic map to draw with the DTED3, which is a big bummer. I opened ticket #1280 for these issues.
You can download the DTED3 for the area from http://www.falconview.org:8080/trac/FalconView/downloads/20 but use it at your own risk!joelodom09/30/10 10:09:27 (3 years ago)
I just noticed some weirdness when I switch from generating the contours from DTED3 to DTED2. It actually appears at a glance that the DTED2 has better resolution than the DTED3. I'm wondering if something didn't get messed up in the data conversion process when I went from 1/3 arc-second NED to DTED3? Then again, all of the additional contours on the DTED2 screen capture (which I will attach) may be "false" contours as they don't seem to follow the pattern of the lakes, etc on the map. The DTED3 may be more finished and smoother, so the contours may be more accurate at this small scale. I'm not quite sure which is the case...joelodom09/30/10 10:33:08 (3 years ago)
DTED 3 is 0.4 Arc second posts in 1 degree tiles, not 0.3 arc second.
9001 pixels x 9001 pixels, 1 pixel overlap to N and E neighborsDanielLonghurst09/30/10 13:37:03 (3 years ago)