Google WebGL Globe Visualization of World Tree Cover

I learned about the WebGL Globe project from this Metafilter post and decided to play around with it while I struggled with late night lab work. I plotted data from NOAA's Advanced Very High Resolution Radiometer (AVHRR), which I download from the Global Land Cover Facility.

The visualization will only run on the latest browsers that support HTML5. Click on the screenshot below to launch the 3D visualization. Very brief technical notes follow.

Technical Notes

The details of the visualization are fairly boring. I used a custom quick R script to parse the .GRD files of coordinates and reduce the number of points to plot. Since the data files were so large, I switched to Unix utilities at times. One neat trick I learned in the process: the following sed command will print every 100th line starting with the 7th:

sed -n '7~100p' input_file

Well, at least it should have. My (Mac's) version of sed had none of it. I turned to awk instead, and this worked:

awk 'NR%100==7' input_file

The implementation of the globe script was fairly straightforward. Be aware, if you're trying to get it to work, that several paths are hard-coded as absolute paths, even in the exteral javascript files. Those have to be changed to relative paths.