I'm trying to think of a practical and inexpensive way to tell at what point tree branches overhang our patio to know which parts can be used for a sukkah. The best ideas I've come up with that seem more precise than just eyeballing it (the branches are quite high) is to buy a drone and attach a long string to it, or use a level to point a laser straight up at the branches to see if they overhang. (Would a device like this work?) Any reasonable suggestions would be appreciated.
go outside, take a strong flashlight, lay it on a flat surface underneath the tree and see if it hits the branches or just disappears into the blackness of the night.
Here are some simple methods to determine if it's hanging over the sukkah, and how much space it's taking.
This method is assuming that the sukkah is already built, and you're just trying to see if any part of the tree is hanging in. Otherwise, see method two, below.
The simplest and cheapest way, would be to look up at the tree while pressing yourself to the inside wall of the sukah. This way, if you see the branch, that would tell you that it's directly on top of the sukkah. But if you don't see it, obviously it's not actually on top.
For this one, make sure the floor of the sukah is flat. And not on a slant.
Get a good laser¹, put it on the floor of the sukkah facing up, and move it around while still facing strait up, and see if it hits the tree.
If it does hit the tree, move it around to determine how big of an area it's taking up.
If it doesn't hit the tree, that would determine that the tree is not hanging directly over the sukkah.
The drone idea is extra and unnecessary work. The laser will give you an accurate answer.
The product you mentioned in your question, is reviewed in this video on Amazon, where the reviewer says that while the product is amazing for indoor purposes, it barely has any use for outdoors being that the laser is not seen past a few feet in daylight. (Great idea otherwise)
1. You can use any accurate laser for this. Try to get one that has a flat bottom, so that you can stand it up accurately.