Geolocating a Random Island Using Geometry and CUDA Programming
A developer solves an OSINT challenge by writing a CUDA program that searches the entire globe for a match to a photo of a resort island. The approach involves extracting geometric fingerprints (triangle angles, distances), filtering OpenStreetMap land polygons, and using GPU parallel processing to test 80 million candidate triangles in 204 milliseconds. After narrowing down with shape and vegetation checks, the island is identified.
80.7 million triples go in, one thread each, in parallel. 158,784 pass the mask.
- NKosmatos
Excellent write up and an enjoyable read! Reminds me of the “good old times” where posts on HN were written by humans and with a specific writing style like yours.
You could’ve used a little bit more of geoguessing to narrow down results, or do a brute force visual check on the last hundred or so ;-)
- bmurray7jhu
For drones and missiles, this technique is known as Terrain Contour Matching. If terrain contour are measured optically, navigation is independent of RF jamming, unlike GNSS.
- zer0x4d
Super fun! Interestingly, this is how JPL was able to significantly reduce the Mars 2020 landing radius on Mars. Cameras onboard take pictures of the terrain and match that to maps to figure out where the lander is. https://www-robotics.jpl.nasa.gov/what-we-do/flight-projects...
- deiptx
I find it highly ironic that his is the second article on the main page right after "avoid building technologies that could be used by a police state".
- sllabres
People liking this post will probably like this [1] and especially these [2] from the channel. All solved using algorithms and map data.
[1] https://www.youtube.com/@colsto
[2] https://www.youtube.com/watch?v=eY-W9gmwxhg