Topic: Topo data

[danallen]

I am an architect developing a house on a 23 acre site in Malibu, California, and I'd like to download 3d topo data for development of a sketchup model of the larger site context. We have a survey of just the site, but would like to expand into the larger area. The google earth sync seems too rough and I'd like to see what other options are out there, for AutoCAD and Sketchup. We do have a demo of QuickSurf that allows us to manipulate 3d data and generate TIN, contours etc, for bring into Sketchup. I thought to find DEM files from USGS via http://viewer.nationalmap.gov/viewer/ which QuickSurf 5.1 is supposed to read, but I seem to be only able to download PDF topos, GeoTIFF, ArcGrid, GridFloat, and BIL_16INT. It seems the national map viewer is new, most of the help pages refer to old defunct websites. (The viewer also needs IE, both Firefox & Chrome get errors)

Any tips?

Thanks,

Dan

[Jeff_M]

Maybe the LA County GIS portal?

Here's the link to the elevation data:
http://egis3.lacounty.gov/dataportal/category/theme/elevation/

The City of Malibu may have more localized data...scratch that, looks like their GIS is too basic.

[Novarese]

GeoTIFF, ArcGrid, GridFloat, and BIL_16INT

ArcGrid is a 100% DEM file, while I'd bet the other ones too, sir.
You can easily triangulate 'em with free tools like Microdem or Qgis.
Here in Europe we can get 1/3" resolution DEMs, whereas I know that in the USA are available stunning 1/9" grids (i.e. 1 pixel = 3.5 meters)

[mjfarrell]

GeoComm.com has free DEM files.
depending on the site location you may want a copy of Global Mapper to piece multiple DEM files together and then clip out only the area you are after