For a school project we are trying to make a device for a bow that can tell you how far away the target is. Since archery is played on a distance of at least 30 meters we are going to need a sensor that can measure this distance. We've looked at ultrasonic sensors for example, but can't find any that measure further than 4 meters. We've also looked into other solutions like infrared lights and GPS, but we just can't find out what would be the best solution to tackle this problem (if there even is any). Does anyone have experience with sensors for quite far distances? The only real requirement that we have is that it can't cost too much. Thanks in advance.
LiDAR can do this.
TommetjeVE:
The only real requirement that we have is that it can't cost too much. Thanks in advance.
If you have enough money, nothing costs too much.
Take a look at existing solutions. The first few I looked at all use lasers.
Google "range finders" for lots of options.