I recently was working with some maps, trying to create some pretty pictures for my thesis using some of the maps by Ron Blakey. However I was too lazy to plot points on the maps by hand and I wanted to georeference the maps. I found a hand tool with QGIS that was easy enough to use, but wasn’t as precise (or as quick) as another command-line tool I found called gdal_translate. GDAL (Geospatial Data Abstraction Library) and the associated OGR comprise a number of tools and libraries that are very useful for both raster and vector geographic image manipulation. Using gdal_translate was easiest with a straight up lat/long projection, as I could just give the geographic coordinates for each of the corners and it would spit out a GeoTIFF. Thus, I was able to quickly take some of the rectangular maps and georeference and have something that I could use in QGIS. While I was playing around gdal_translate, I found another tool called gdalwarp, which has been giving me a bit more of a headache. Theoretically, gdalwarp should let me transform some of these rectangular maps into different, possibly ‘prettier’ looking maps. So far though, all I’ve managed is to make some seriously un-pretty images. I’ll post an update in a little while giving some quick instructions once I figure out how to make it all work.
Entries from July 2009
Map projections and gdalwarp
July 6, 2009 · Leave a Comment
Categories: Uncategorized
Tagged: gdal, gis, palaeogeography
Sasquatch Distributions
July 6, 2009 · Leave a Comment
A paper from the Journal of Biogeography was published online today about ecological niche modeling the Sasquatch. While the name of the paper may excite a lot of cryptozoologists and Bigfoot believers, the authors use this oft-sighted-never-captured creature as a good example of why questionable occurrence data should always be taken with a grain of salt. The paper actually concludes by stating that based on the overlap of the predicted range of Satchmo and black bears, most of the sightings reported have been mistaken identities (although it is difficult to tell if they mean Bigfoot is really just a black bear, or if black bears are actually just really hairy cousins of ours).
Categories: Uncategorized
Tagged: gis, sasquatch, biogeography
