I like the idea very much as I have played also somewhat with the GTOPO30,
and the NASA DEM data. My personal interest is the Iberian Peninsula by the
way (oh! maybe Deception Island too, which I visited, 20 years ago...).
It is a project with ambition. I think that I would need another PC anyway
for better data crunching (something I am thinking about seriously)... and a
lot of theoretical help too. I am really a lay person in this matter. Time
would not be a problem, though.
I am tempted to contribute...

Thomas


news:4324810e$1@news.povray.org...
> High!
>
> Everybody is talking about GoogleEarth... even in less high
> tech-enthusiastic countries like Germany, the issue made it into prime
> magazine stories. But as GoogleEarth aims to be a real-time navigable
> representation of our planet, its level of detail is limited and far
> from photorealistic. As a commercial, proprietary project, the satellite
> and aerial imagery also is tagged over and over with those annoying "(C)
> 2005 Google" watermarks. Then, for vast parts of Earth's land mass,
> GoogleEarth's satellite maps are of lower resolutions as publicly
> available nowadays (for example the Landsat series).
>
> So what about starting a PoVEarth project? There are terabytes of public
> domain NASA/JPL image mosaics available, down the line at 0.5 arcseconds
> /pixel, which equals about 15 m/pixel on the equator. And not only image
> mosaics, but also altimetry data at a horizontal and vertical resolution
> high enough to do it without vertical exaggeration (3 arcseconds per
> sample, 1 metre vertical accuracy)! In my last rendering of Afghanistan,
> I used one of these 1 by 1 degree tiles...
>
> We could start with an overview representation of the Earth made of,
> let's say, 5 by 5 degree image mosaic tiles and the less accurate
> GTOPO30 altimetry data (15 arcseconds per sample, yet still 1 metre
> vertical accuracy) and then gradually filling in with the more precise
> datasets.
>
> Quite a challenge would be the color adjustment of the tiles, as they
> were photographed during several Space Shuttle Radar Topography Missions
> (SRTMs) in 2000 and 2001, so frequently adjacent portions of the tiles
> were shot at different daytimes and seasons, consequently showing
> different lighting angles, vegetation status and snow cover (an example:
> Tierra del Fuego on http://makeashorterlink.com/?H130237CB - note the
> sharp boundary between mountains deep in snow and almost snow-free or
> between dry reddish and lush green pampa!
>
> At a later stage of development, we could again start filling in even
> larger-scaled altimetry data derived from printed maps (for example 1 :
> 25.000 topographic maps) and converted from geodesic to simple
> cylindrical projection, same with aerial photographs replacing satellite
> images... this also would be the time to start populating the landscape
> with actual single rocks, trees and buildings.
>
> After the first "overview" modeling, each participant of the project
> might start modeling one certain place, region or country more
> thoroughly - whether this might be his or her home town or some other
> area of personal interest. With me, this would include the Cologne area,
> of course Afghanistan and some subantarctic islands...
>
> We PoV people don't have billions of dollars behind us. But we have
> thousands of gifted and enthusiastic programmers and multimedia geeks,
> and, most important, no deadline! No banks and shareholders would
> prevent us from embarking upon a decades- or even centuries-long
> raytracing adventure which only the grandchildren of our grandchildren
> live to complete. This soon could develope into one of the largest and
> longest-lasting non-profit computing enterprises ever undertaken...
>
> So, now what about PoVEarth?
>
> See you in Khyberspace - and not only there!
>
> Yadgar

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