I would guess they do it by hand, as you suggest, but I would also guess they use some kind of GPS surveying technology, now, to get it all so perfect.
TheJapanChannel.com
2024-06-30 01:35:30 +0000 UTC
That's got to be a painstaking process! My back hurts just looking at it. (Starting to rethink "crop circles" now, as well.)
How in the heck do you do this?