Geolocating a random island using geometry and CUDA programming

(yassa9.github.io)

167 points | by yassa9 3 hours ago

17 comments

  • NKosmatos 1 hour ago
    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 ;-)
    • jambalaya8 9 minutes ago
      agree! AWESOME work!
    • yassa9 1 hour ago
      yea, thanks :D , I used a tiny idea from geoguessing, that I banded the search on islands only in latitude between -30 to +30 deg. based on the sky and the tropical vibes in the img , and it worked !
  • bmurray7jhu 2 hours ago
    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.

    https://en.wikipedia.org/wiki/TERCOM

    • yassa9 1 hour ago
      oh, wow, I didnt know that existed, thank u, sure gonna look into it
  • o4c 1 hour ago
    Really great article! OP, you did an awesome job breaking down a complex problem into manageable chunks and synthesizing the solution.
    • yassa9 57 minutes ago
      thanks, appreciate it
  • dwa3592 51 minutes ago
    This is awesome. I worked on something similar a few months ago. It is a general purpose navigation system based on TERCOM and dead reckoning - https://github.com/deepanwadhwa/anumaan
  • num42 23 minutes ago
    Good article! Off-topic, Is Palantir doing the same thing with its internal software to geolocate?
    • yassa9 18 minutes ago
      thanks ! no idea about Palantir, but in my opinion, this can not be automated , needs much manual work and tons of trial and error
  • lexlambda 2 hours ago
    OpenStreetMap data really is a godsend for such OSINT purposes. Works much better in populated areas too, with more features like roads, shops, electric lines that can be used to search.
    • GaryNumanVevo 54 minutes ago
      Claude / Gemini + OSM Turbo is a crazy you can do natural language queries like "find me a bus stop in germany that's surrounded by more than 5 three story buildings"
    • yassa9 2 hours ago
      yea , heard about them before, but didnt know that whole treasure till I really used it , impressive
  • ImJasonH 49 minutes ago
    Excellent read, I loved it.

    Incidentally, the image seems to be the one the resort uses on their website! https://oanresort.wixsite.com/chuuk

    • yassa9 33 minutes ago
      thanks, and yea, it should be solved easily by passing the img to google lens, the website is the first result, but I found a fun opportunity to solve it in different way
  • cecinuga 2 hours ago
    I read all the process, literally awesome, i don't do OSINT (i know only what is this) and i think that's very cool
    • yassa9 2 hours ago
      thaaank you !! Its my first ever challenge to do, and yea, I really found my passion
  • ape4 1 hour ago
    What about tides? Would the outline of the island be different based on the time of day.
    • yassa9 53 minutes ago
      honestly, I didn't think about it, I just trusted the OSM polygons
  • bitcurious 2 hours ago
    It’s interesting that most top contenders don’t pass the eyeball halo check, seems like there’s room to optimize that filter in code.
    • yassa9 2 hours ago
      yea, good observation, my guess is its the data more than the filter. OSM coastline polygons are generalized to different degrees depending on who traced them and from what imagery, so the fine shape detail a halo check would key on often is not in the geometry at all.

      I observed that at the end, didnt push on it further though. It already passed and I was super exhausted

  • phalanxx 1 hour ago
    What do you mean by no LLM generation if an LLM did all the coding based on reading through the .py files? Pangram isn't kind to "your" text either.
    • yassa9 1 hour ago
      I meant the blog itself, the writeup, the steps and the walkthrough all by hand , the final code u see is llm refined, of course, I wont publish my messy and spaghetti files with much tests, failures and dead ends, also vizualizations functions to produce that green maps , and faulty versions of them

      but you are right, I should add that

      • StilesCrisis 1 hour ago
        Just by reading your actual messages it's easy to see that you didn't write the blog post entirely by hand.
    • StilesCrisis 1 hour ago
      "No EXIF, no GPS, no camera make or model."

      Yeah, a human definitely wrote this. Nothing fishy here. (Why would the camera make or model matter???)

      • yassa9 1 hour ago
        ok, if u came with the whole conclusion by only this line, ok , but to answer u, ( I hate to justify myself , but have to ) I started writing the blog after I started solving another challenge from gralhix : https://gralhix.com/list-of-osint-exercises/osint-exercise-0...

        and the part of the solution came from the metadata, the camera model, you can check urself, so when I came back to write the blog, it just came by flow,

      • voidUpdate 1 hour ago
        If you know the camera make and model, you might be able to get lens parameters and get better estimates of real world geometry from the image
        • yassa9 1 hour ago
          yea thank u, that's another part, but mainly it would hard although knowing that, because you need to know elevation of the drone or the camera, which is also extremely difficult (I already mentioned that in the blog)
          • StilesCrisis 46 minutes ago
            The camera make and model wouldn't tell you the lens parameters. The EXIF would, but that was already covered in the triplet.
  • hhh 2 hours ago
    great blog and great writeup
    • yassa9 2 hours ago
      thannks, really grateful :D
  • piterrro 2 hours ago
    really impressive, could that be the way to locate yourself without GPS? assuming we know more/less where we are
    • yassa9 2 hours ago
      yea, search about geoguessing on youtube, people like Rainbolt, https://www.youtube.com/@georainbolt

      they literally memorize and get patterns of every possible road, place, map of any area (scanned by google earth), getting exact coordinates from single image, and play competitions and world cup based on that

      they do really nice videos about finding places in old photos people ask for

  • grodes 2 hours ago
    impressive
  • fenestella 2 hours ago
    [dead]
  • ohyoutravel 2 hours ago
    > NOTE: this is a genuine human work, didnt use LLM generation.

    A million upvotes from me.

    • yassa9 2 hours ago
      haha, thanks :D I was hesitant to whether write it or not, but I really really despise llm generated posts and blogs and im glad someone appreciated it
  • hno8a34nwn 1 hour ago
    This is the real takeaway