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General Category => Map Making Support => Topic started by: hwstock on June 07, 2013, 10:07:58 PM

Title: Other sources of DEMs for Mexico
Post by: hwstock on June 07, 2013, 10:07:58 PM

I've just used the USGS server to get 1 arc-second DEMS for Mexico. These work (with some reregistration), but I'd like at least 1/3 arc-second.

I just need fairly small areas-- like a 24k quad-worth.

Have you folks ever tried the commercially-available DEMs?  I'm guessing they are pricey. Examples:
http://www.landinfo.com/products_dems.htm

Title: Re: Other sources of DEMs for Mexico
Post by: Indrid Cold on June 07, 2013, 10:52:44 PM

Here's their cost:

http://www.landinfo.com/mexstate.htm

Title: Re: Other sources of DEMs for Mexico
Post by: maps4gps on June 28, 2013, 02:14:24 PM

There may not be any more detailed data available.
Consider:
  The scale of the standard topo for the US is 1:24,000.  USGS first produced 1 arc-sec gridded elevation data from these and more recently using more refined algorithms produced 1/3 arc-sec NED.  Since Mexico's (and Canada's) standard topo scale is 1:50,000, 1 arc-sec is a sensible limit on what could be produced. 

Check with the Mexican government to see if anything more detailed is available. 

Title: Re: Other sources of DEMs for Mexico
Post by: hwstock on June 29, 2013, 05:41:49 AM

In areas that overlap with the US, the usgs will supply 1/3 arc-second. Some of these seem to be interpolations on much of the Mexican side, but others do have the detail one expects for 1/3 arc-second (based on comparisons with the GE images.

I used to work for a company that occasionally would contact finer detail satellite (LiDAR) from commercial vendors... back in the days when cost was not an issue. ;^)

Title: Re: Other sources of DEMs for Mexico
Post by: maps4gps on June 29, 2013, 06:39:08 AM

USGS has some 1/9 arc-sec LIDAR available which extends about two miles into Mexico.
http://ned.usgs.gov/usgs_gn_ned_dsi/viewer.htm