4 replies to this topic

[Dennis McClendon]

I'm starting work on a tabloid-sized map of Washington State that will lap into British Columbia and Oregon a bit. It's for a book, and will be about 2 million in scale. Please refresh my memory on the easiest sources and methods for putting in shaded relief at that scale. I have ArcGIS 10, but not any of the extensions.

[David Medeiros]

For elevation data sources the best for free hi resolution US data would probably be the Seamless Server:
http://seamless.usgs...less/viewer.htm

very high quality global data at 90m can be found at CGIA:
http://srtm.csi.cgia.../inputCoord.asp

On methods I use Natural Scene Designer Pro. Relatively inexpensive and pretty powerful. There are a few smaller shaded relief tools around, like MacDEM (not for newer versions of Mac OS though). ArcGIS will shade a DEM directly from the properties menu of the DEM layer and you could output that as a tif to adjust in photoshop. Relief from Arc never looks that good to me but I'm sure it can be finessed.

[Adam Wilbert]

Everything goes wonky once you try and cross that US/Canadian border. Unfortunately, I practically live on the border, which makes data acquisition a real headache! I typically pull tiles from the USGS SRTM server at http://edcsns17.cr.u...wEarthExplorer/ when I need international elevation data, but it's only the 3 arc-second (90m) data that is available. The problem with most (all?) online sources is that you have to grab dozens of tiles and merge them together. The EASIEST option would be to buy a data DVD that has the entire SRTM set already put together, but that doesn't come as cheap.

[sitesatlas]

Since you have ArcGIS 10, you might be interested in the Supplemental World Imagery set of four DVDs from Esri. It includes SRTM and GTOPO data for the whole world and it's free if you're on the maintenance program. It could definitely come in handy -- I've just ordered mine.

[rudy]

You can access Canadian DEMs from Geobase as long as you don't require detailed resolution - they seemed to have botched the creation of the DEMs, resulting in a stair-stepping effect. If you are able to, you can recreate your own DEMs from 1:50,000 NTS data available from Geogratis.