I'm interested in obtaining Digital Elevation Models for areas in the 20,000 acre range, as I use them to create contour maps for agriculture.
The USGS Earth Explorer has a wonderful free DEM database with world coverage, which is important to me, since I live in Argentina. Sadly, the resolution for the global dataset is too coarse, so it's useful to analyze whole countries, but not for smaller scale analysis.
So I searched the web looking for commercial satellite data providers that offer DEM files.
I found two companies that offer satellite imagery and derived products, like preprocessed DEMs, with worldwide coverage:
Airbus Defense & Space (http://www.geo-airbusds.com/worlddem-sampledata/) BlackBridge ( http://blackbridge.com/rapideye/all-products/nextmap.html )
Of course, the data is not cheap, and, at least in the case of Airbus, they'll not take orders of less than 500 km2.
I wonder if there are any other providers of this type of data, ideally free and open, but realistically, commercial, that may be better tailored for smaller scale projects. A resolution of around 12m is perfect, but in the case of free/open sources, of course beggars can't be choosers :)