The heightmap was added in rP15219.
Check if those files are indeed useless.
Did you try to grep for references to these files ?
Could also run checkref.pl :)
Looking at it it seems that the height map was used to create the map and that the author left it here in case someone wanted to recreate it.
I'd say we move it to the art source repository :)
I did grep it.
Could also move it to the maps/skirmish directory which already contains some heightmaps like the Greece one. But I never saw the point of keeping those heightmaps in this repo. Art repo seems to be a better place.
Bonus question: Did michael leave any word about the source of this file on the forums or irclogs or can we assume that to be copyrighted material like was with many of his or mine heightmap commits as well, thus warranting to delete/reproduce the map as well (given that there was no copyright claim in the concerning commit and we already had to delete 12 heightmaps for that reason)?
Is that heightmap accurate? I could find no resemblance with that heightmap or the skirmish map to the real place.
Edited for a better more trustworthy link.
Did a quick lookup since I have the related data on my disk anyway:
Couldn't find anything in irclogs in 2014 for "siwa", "nasa", "srtm", "heightmap", "topography" or "Mythos_Ruler".
Blue Marble data looks different, can copy&paste from lower_nubia.js etc.:
lat=29.205278; lon=25.519444; width=10
lat1=$(bc <<< ";scale=5;$lat-$width/2"); lon1=$(bc <<< ";scale=5;$lon+$width/2"); lat2=$(bc <<< ";scale=5;$lat+$width/2"); lon2=$(bc <<< ";scale=5;$lon-$width/2"); gdal_translate -projwin $lon2 $lat2 $lon1 $lat1 gebco_08_rev_elev_C1_grey_geo.tif lower_nubia.tif;
convert lower_nubia.tif -resize 512 -contrast-stretch 0 lower_nubia_heightmap.png;
That's not a topographic map, but the bodies of water don't match.
Perhaps it was SRTM. But it seems plausible that the heightmap comes from a different location to begin with.
As the image was mostly likely downloaded from somewhere and not drawn manually, safer to treat all files of the derivative work equally (i.e. either document this as a possible copyright violation and get a clarification before acting or delete the derivative work to rule out a copyright violation).
lat=29.205278; lon=25.519444; width=5; lat1=$(bc <<< ";scale=5;$lat-$width/2"); lon1=$(bc <<< ";scale=5;$lon+$width/2"); lat2=$(bc <<< ";scale=5;$lat+$width/2"); lon2=$(bc <<< ";scale=5;$lon-$width/2") gdal_translate -projwin $lon2 $lat2 $lon1 $lat1 gebco_08_rev_elev_C1_grey_geo.tif siwa_oasis.tif convert siwa_oasis.tif -resize 512 -contrast-stretch 0 siwa_oasis.png
What I had used, Couldn't get something related even after tweaking a lot.
Would also be good to know from which location it came from, since it doesn't appear to be Siwa Oasis. If we know the location, one could compare.
Without further information, it is at least uncertain whether this image and the pmp file are a derivative work violating the copyright of the author.
I think most NASA material is public domain, most SRTM versions were usable for us (just not the one specific modified SRTM version we had used).
From a visual comparison we can confirm that the png file is the same as the pmp file, or at least certainly a "derived work" under US copyright.
It's not NASA Blue Marble of Siwa Oasis as we tested that last time.
If it's NASA SRTM of Siwa Oasis as we can see 8 or more SRTM sets with some clicks in https://earthexplorer.usgs.gov/ and they all look equal but entirely different from the committed png.
The heightmap might come from NASA, since most publicly accessible maps come from there. But it would have to be some other location of the earth that was just claimed to be Siwa Oasis.
Or the PNG was reworked from top to bottom up to the point irrecognizability, creating entirely new hills and lakes, which seems unlikely.
The author doesn't recall the exact origin of the heightmap and has practiced taking things that are free as in beer but not free as in GPL v2+ / CC-BY-SA before.
The burden of proof is on the one committing the map that the licensing is correct.
The map is not bad, so it's loss that it has to be removed from the repository until someone can clarify this or write some fancy algorithm to find the location of that heightmap.
(There is a scenario map called Siwa Oasis which looks entirely different. More realistic if that map is centered around that western smaller oasis.)
That one doesn’t have to be deleted ofcourse. Looks like it was handmade. Just putting it out here.
No further information available other than a heightmap of an unknown location of an unknown NASA elevation map. Supposedly multiple heightmaps superimposed and one of them being from Siwa Oasis.
But I can't recognize the location from NASA heightmaps that all look very similar.
From a visual inspection, and a comparison of the resolution to the blue marble heightmaps, I would say it's a random mountainrange with black water and white hills being added in an image editor.
Siwa oasis google maps:
Siwa oasis map in question:
Siwa oasis scenario map:
Siwa oasis blue marble topography:
Siwa oasis map in question:
Blue marble composites random USA mountainrange: