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Could you not reproject those images to what you're after using something like GDAL or QGIS?
Finding a world map with an isostatic rebounded Antarctica
Hello! I'm looking for a world map with the rock-equivalent topography for my worldbuilding topography.
Something like these images here,
I want an equirectangular map of this in it, so I can get the accuracy of Greenlandic and Antarctic topogrpahy.
Could you not reproject those images to what you're after using something like GDAL or QGIS?
Probably not. I did find some bedrock world maps in the equirectangular projection. But the Antarctic and Greenlandic topography have not been isostatic rebounded. I'm trying to find an equirectangular map with the rock-equivalent topography. Like the bottom right image of Antarctica.
Also, how would you use those programs in this scenario? How do you use them?
[ EDIT: read my next two posts before wandering too far afield ]
I suppose it does come down to what you want to do with them. There is also a major element of your familiarity with the subject matter (especially GDAL and/or QGIS) and what level of accuracy you're interested in.
https://nsidc.org/data/user-resource...graphic-latlon shows how to take a polar stereographic map like the Antarctica ones and convert it back to the basic equirectangular one.
The most direct way might be to send an e-mail to the folks who published those maps asking if they have published the DEMs. With the digital elevation models in hand, there should be any number of ways to get shaded data out and those DEMs are likely to come with metadata that's easier than eyeballing it from low-resolution data.
Many years ago, I wrote a crude tool for eyeballing data. You'd need to play with settings a lot to get a good result, but your input data is low enough resolution that it probably won't be too bad. That's http://fracterra.com/ReprojectImage.zip if you are willing to install a Windows executable from the internet. It looks like I lost my "www." somewhere along the way, but I'm not going to worry about it. It's also not https as I never bothered to get a certificate, so your browser may or may not complain. I did a little trimming and reprojecting earlier today and came up with the attached image. You can probably do better with a little more patience than I have. Precision tools like GDAL and QGIS will let you do a much better job, of course.
Last edited by waldronate; 02-17-2023 at 10:55 PM.
I suspect that you have already come across the data sets associated with that last image you published at https://ddfe.curtin.edu.au/models/Earth2014/ with descriptions of the data sets? It includes a simple equirectangular binary raster that you should be able to stuff those into your favorite rendering software and get out what you're after. Specifically, the file https://ddfe.curtin.edu.au/models/Ea....1min.geod.bin is a raw raster with the rock-equivalent topography for the whole world and https://ddfe.curtin.edu.au/models/Ea....1min.geod.png is a hypsometric color file showing what it would look like.
The bin file is 21600 cells wide and 10800 cells high in 16-bit big-endian 2-s complement signed format, if that helps any.
Last edited by waldronate; 02-17-2023 at 10:42 PM.
Alrighty, I downloaded that DEM and looked at it in Wilbur (it was handy and I'm familiar with it) and got this badly-cropped screenshot (the original image is 21600 pixels wide and this machine doesn't have much in the way of image handling software installed on it):
I was a little surprised to see less rebound in the Baltic areas the I had expected, but the Great Lakes in North America are pretty much gone, so that's good.
Here are the Wilbur ( http://fracterra.com/software.html ) settings if you'd like to try it yourself:
Last edited by waldronate; 02-17-2023 at 10:55 PM.
How did you look at that bin file into Wilbur? Does G-Plates support bins?
In Wilbur, use File>>Import Subsection and enter the data shown above. If I recall correctly, the raster was flipped vertically, so Surface>>Rotate>>Flip Vertically gets it back to its original orientation.
I don't know what G-Plates supports for its input formats, but there may be one that Wilbur can export if a .bin file isn't natively supported.
Can Wilbur convert a map like this into equirectangular?
Can you try to convert the map?
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