You need a camera with a powerful telephoto lens like a Nikon P900/P1000. So many people have done this over the past 10 years you can save yourself the effort unless you think they're all liars. Taboo Conspiracy does the simplest tests with lasers around lakes in Utah. I think his latest test picked up a laser about 17 miles away that was two feet off the ground that should have been hidden by almost 200 feet of curvature. He's done dozens of these experiments as have hundreds of other people.
But if you REALLY wanted to do this yourself you'll need the camera at a minimum. You could also do this with a GPS-equipped boat on the ocean. The only difficulty with this method is that waves can cause you a lot of problems and block objects in the distance as well as humidity, condensation, etc. Larger lakes on calm days are easier to test with.
You need a camera with a powerful telephoto lens like a Nikon P900/P1000. So many people have done this over the past 10 years you can save yourself the effort unless you think they're all liars. Taboo Conspiracy does the simplest tests with lasers around lakes in Utah. I think his latest test picked up a laser about 17 miles away that was two feet off the ground that should have been hidden by almost 200 feet of curvature. He's done dozens of these experiments as have hundreds of other people.
But if you REALLY wanted to do this yourself you'll need the camera at a minimum. You could also do this with a GPS-equipped boat on the ocean. The only difficulty with this method is that waves can cause you a lot of problems and block objects in the distance as well as humidity, condensation, etc. Larger lakes on calm days are easier to test with.
Here's Taboo Conspiracies channel if you want to try and emulate his methods: https://odysee.com/@TabooConspiracy:c
Good luck!