Hi,

For what I can see France Digital Terrain Model resolution is good enough to be viewed at 1:100.000 scale and be close to 1 sample per pixel on the other hand Spain DTM roughly is 20 times less dense, there is an official source (Instituto Geografico Nacional / National Geographic Institute) available at 200, 25 and 5 meters per pixel for the whole Spanish territory.

Is there any chance you could use that source (it is free for personal use but I believe it is paid for commercial use) to improve the actual SD?

http://www.ign.es/ign/layoutIn/modeloDigitalTerreno.do

Thanks

Isaac

Hi Tim,

Spain is the second roughest country in Europe after Switzerland, you will not see big heights but the terrain constantly goes up and down, this is a (mostly) irrelevant fact for General Aviation but it is a critical factor for gliders and Ultra Light aircraft (in Spain the law mandates that Ultra Lights must fly below 1000 feet AGL).

I don't consider myself qualified to decide what should and what should not be represented at a higher DTM density (you already clarified what is your policy on this) so I will provide some elements to decide what should be done.



This map covers Catalunya (North East of Spain), the red color indicates a slope of 60% or higher and the green color represents a 0% slope, as you can see most of the country displays high terrain height variability which may be a factor for low flying (<1000 feet).

This example can be extended to most of the Spanish ground with some exceptions, if you want I can present a similar study for the rest of the Country (at high resolution not like the image presented here).

Cheers

Isaac