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Guest tlc8126

USGS SDTS Data still available...

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Just a note to all who use TerraScene...I was able to access and freely download DEM (7.5 and 15 meter datasets) from the following link: http://www.geocomm.com/You need to create a login account (free) to download files. Then click on the 'GIS Data' tab along the top of the web page. I clicked on the USGS DEM's link under 'TOPICS' on the left side of the web page and eventually was able to see DEM's, DLG's, and LULC's - everything I needed to get TerreScene up and running again. (A 'Premium' account for the above link would cost but is more geared for businesses needing the data on a more frequent basis than most Flight Simmers.)Also, here is a link to the USGS SDTS page that told me to go to the 'geocomm.com' site, and also gave me more information on SDTS data sets. It mentions that the USGS wants the data to continue to be free, but also wants private/commercial vendors to have more access in the distribution of data. From the USGS web site: http://edc.usgs.gov/geodata/"The decision to provide SDTS DEMs through commercial vendors is consistent with the USGS goal of making more public domain data available at no charge while enabling the private sector to have a greater role in the distribution of USGS data. SDTS DEMs placed on media in response to customer orders will be sold by our partners at a price less than the USGS currently charges."Notice the phrase "at no charge", and "while enabling the private sector to have a greater role in the distribution of USGS data."Finally, there is the following web site. I am not sure if I need it just yet but it appears that you can download various types of USGS data, possibly DEM's, DLG's, and LULC's. It also looks like you can get Satellite Imagery. If anyone has the time to play around with it, or has already done so, please let me know what you find.Aloha'sThomas C.

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OOPPSS!!The USGS DEM info pages indicate that the data is 7.5 and 15 'minute' data (not 'meter'). Aloha'sThomas C.P.S. If anyone has a good understanding of how the data is specified - i.e. 7.5-minute, 1:24,000 scale vs 15-minute, 1:100,000 or 1:250,000 scales - can they please post a good note (or a link to a good web site) explaining this? I tried reading the USGS web site at http://rockyweb.cr.usgs.gov/elevation/2arcinfo.html but got a bit lost. Thanks!

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In my first post above I forgot that last link:http://seamless.usgs.gov/Its for something called the Seamless Data Distribution System. You're supposed to be able to download DEM's, LULC, DLG, etc for a larger area than you normally could in the standard 30 minute quadrangles, etc. I haven't figured out how to do it yet. I guess I should read the 'Tutorial'. (If it has a tutorial it must not be very easy to use!)Aloha'sThomas C.

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Aloha Thomas! Thanks for the links and info. Should help many of us who had links to the old sites, and lost em in computer reconfigurations .Hopefully Randall Rocke will see your other posts, as he's one of our best Terra-sceners, and may be able to answer your questions.Again, thanks for the info!Aloha!Ken Wood :-sun1http://www.avsim.com/hangar/fly/dfdg/bannernewkw.jpgGateway 700X; Intel P4 2.4GHz; 512MB RAM; NVIDIA Ti4200 4X AGP 128MB; SB Audigy; Thrustmaster TopGun Fox 2 Pro Shock

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Thomas,Though I have a ton of experience now with TS, it's all been with the default data access or shapefiles. I did pioneer some work accessing Tiger Census 2000 shapefiles to update land use and combined this with the higher-res USGS data.As far as I can understand Todd's programmimg, TS is set up to work with 1 deg. DEMs with a resolution of 90 meters and 7.5 minute DEMs at a resolution of 30 meters for shading. Now, there are settings within the program that may allow for different data to be used, but I do not have experience with other data types. Someone like Colin Sare-Soar may know what types of data may be used or whether the program can be adjusted.I would note that I did receive a "care package" from Frank Racis that has most of the original USGS data (set of 3 DVDs). I will be happy to produce copies of these and ship them to needy TS users if they would also copy them for others. If we work together on this, we can keep TerraScene vital in the community. When you generate new scenery, I recommend creating a data pack that includes everything a person needs to generate the same area. That way, the data pack can be uploaded to the file library with everything a person needs - as long as they have the TerraScene program they can make the scenery. I recommend global tile sets.

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The only problem I can see when using data that never changes is that 'it never changes' while the world does.That's not to say that the DEM or other data doesn't change, but I read on one of the links I posted in my original message that the data for DEMs is updated periodically . So, if a mountain range is gaining in height for some reason (plate tektonics?) we might want to have the mountain at the new height - thus we'd want the latest DEM (I guess that would be the 1 degree DEM?).As far as I can tell the different sites for free DEM (7.5 minute) don't have any ftp servers to point your TerraScene to. (You can easily change the URL under the TS Main Menu by using "Projects -> Advanced Options", then editing the properites under "TerraScene2 Settings -> AutoDownload -> DEM75" or other type of digital data file.) If I could find an ftp site that worked I'd let you all know, but I am certain others have looked into this before me without any success. As for 1 degree DEM, LULC, and DLG, I haven't checked into their availability, but from the sound of things in these forums there isn't a problem. I have never used Shapefiles so I could use some pointers as to how to use them, when they are necessary, and what they are.Aloha'sThomas C.

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Thomas,I noticed that USGS files that are still freely downloadable (though you have to jump through hoops to get them) have a different naming convention than what they used to have "back in the day" when I used TerraScene on a regular basis. They used to be named by county name (I think) and lived in sub-directories of "TerrasceneUSGS" folder (eventually broken down alphabetically). But now they have a bunch of numbers for file names.Where exactly do you park these "new" files inside the Terrascene 2 folder structure so that TS can pick them up and use them?Thanks,Michael

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