Converting DEM Topo Data to BIL Format
Q: Can I use USGS DEM or Canadian CDED data files with TAP?
A: With TAP5.0.1057 or later and a Maintenance Subscription date of May 31, 2005, or later, the TAP Topo Utilities module can be used to convert the USGS DEM format files to the .BIL format. The CDED files available from the government of Canada that use the DEM format can also be converted.
Note that all values in this example are for demonstration purposes only. You should determine appropriate settings for your application.
USGS DEM files are available from http://seamless.usgs.gov/
Canadian CDED files are available from http://www.GeoBase.ca/geobase/en/index.html
To convert the DEM / CDED format files, use the “Import USGS DEM to BIL Format” selection from the Utilities|Topo Utilities menu in TAP6:
In earlier versions, the function is under the Topography menu:
You will be prompted to select the folder where the DEM files are located:
If the files are in sub-folders below another folder, you can select the top level folder and the files in the sub-folders will all be imported.
The files must be the ASCII DEM files. If the files are zipped they must first be unzipped.
Click the OK button when you have selected the folder.
You will be prompted to select (or create) the folder where you want to write the new files in the BIL format:
Click OK when you have selected the folder you want.
The conversion process will start, displaying the file name and progress in each file:
When the conversion is completed, any files not processed will be listed:
The unzipped downloaded files often include other “metadata” information in files which are not converted.
A reminder message is displayed for indexing the newly converted data.
Select Topo Data from the TAP Configuration menu:
Click the “Browse folder” button to select the folder where you wrote the new files:
Select the folder where the new data files are located:
Click the OK button to start the index process.
The files will take a few seconds to index, then the results will be displayed.
The indexed data files can now be used in TAP.
If you need help converting DEM / CDED data files, and you have a current SoftWright Support Subscription, you can contact support@softwright.com
If you have a problem with a particular DEM file, it will usually be helpful to email that file with your support request.
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