Posted by tombh 14 hours ago
We go into all the details at https://alltheviews.world
And there's an interactive map with over 1 billion longest lines, covering the whole world at https://map.alltheviews.world Just click on any point and it'll load its longest line of sight.
Some of you may remember Tom's post[1] from a few months ago about how to efficiently pack visibility tiles for computing the entire planet. Well now it's done. The compute run itself took 100s of AMD Turin cores, 100s of GBs of RAM, a few TBs of disk and 2 days of constant runtime on multiple machines.
If you are interested in the technical details, Ryan and I have written extensively about the algorithm and pipeline that got us here:
* Tom's blog post: https://tombh.co.uk/longest-line-of-sight
* Ryan's technical breakdown: https://ryan.berge.rs/posts/total-viewshed-algorithm
This was a labor of love and we hope it inspires you both technically and naturally, to get you out seeing some of these vast views for yourselves!
So in mine you can click on a spot and it draws black lines over any land that is occluded by terrain, within 100km.
(But all with AI-generated JavaScript, not cool Rust and SIMD stuff)
This is what I get when I set the observer height to 20m, and increase the "max distance" to 300km (200km = ~124 miles so may not be enough).
https://img.incoherency.co.uk/6478
It's also possible that the half dome is too short and the sampling rate of the line-of-sight jumps over it!
Heh, I almost hit back at the "in Rust" mention.
Would the end result have been different if it were done in python calling C libraries for performance? I strongly doubt it.
1) Poking around our local peaks I find that the calculation appears granular, it's offering me things I could see from the summit that I could not see from where I clicked.
2) It's offering me one I never even considered looking at (peeking just beside another mountain, the terrain appeared flat, I never realized there was a distant peak there) and one I knew about--and know I have no hope of actually seeing.
https://map.alltheviews.world/longest/-83.1653564346176_29.8...
Ultimately we plan to mix in higher resolution data from different more recent surveys.
[1] https://beyondrange.wordpress.com/2016/08/03/pic-de-finestre...
This is an independent observation from the Fabra Observatory: https://english.elpais.com/elpais/2015/03/03/inenglish/14253...
I did some longshots back in the early days of wifi.
You could probably talk between ends using cheap crappy 446MHz 250mW walkie-talkies though.
But then the actual message would be encoded by very slightly favouring the high or low end of the spread spectrum map as a kind of terribly slow FSK.
Thanks for this tool!