Covered on these pages are a number of notes on taking SDTS format data and converting it to a format that can be more easily used in GIS software. The emphasis is on DLG format and ESRI format data, both of which are used by many GIS programs.
One of the methods included here can be used to import SDTS data into ArcView and link the related attribute data. DLG format data are an intermediate product of this method. The steps and tools used were developed by a number of people and refined to this point via discussion on the ARCVIEW-L discussion group. The methods could still use more refinement: contact information for offering comments can be found at the bottom of the page. Particular thanks for the work so far to Jeremiah Bergstrom, Mike Sloop, Sol Katz, Mark Negri, Lee Padrick, and Mike Beardslee. These tools were developed mostly for the 1:24,000 (Large) scale SDTS data, but will also work for the 1:100,000 scale data.
This method has been tested on a number of files. A couple of generalizations; while it runs fine on Win95, the dlgbld.exe program will NOT run on Windows NT (ver 4.0). All the other programs seem to work. Also, only the hydrology and transportation data have been thoroughly tested with this method and given consistent results. Boundary information and public land survey information are being tested now and notes will be available shortly. The topolopgy on those files seems to convert consistently but there are still some questions on the attributes. The manmade features have not yet worked at all, while the surface cover and nonvegetative features have been inconsistent, meaning that not all of the features will relate to attributes or not all of the features (especially polygons) will show up in the shape file (although occasionally everything works).
While this conversion method looks long and complicated, it actually goes fairly fast after you have done it a few times. There are lots of notes included below that you will not need after the first time through.
The other method discussed is the direct SDTSIMPORT command, used by Arc/Info. While the command imports and converts data well, the steps to relate the attribute information in the Info files created by the import are not immediately obvious. This is due in large part to the nature of SDTS data. There are many associated files in SDTS data, and the import maintains many separate files; therefore quite a bit of knowledge concerning the SDTS format is needed to make sense of the imported files.
These pages will be under constant expansion for a while; input and comments are welcome, via the contact information below.
For additional information regarding this Web page, contact Chris Lett National GIS Coordinator, in the Division of Information Resources and Technology Management, at Chris_Lett@fws.gov
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Keywords=GIS, data, SDTS
Last Modified January 04, 2001 07:46 AM