What Makes a Laser Range Finder Accurate and Reliable?

[Blue Scallop]

What is the most accurate range finder have you come across? If the laser hit a surface that won't reflect.. would it still register?

 

[Baluncore]

What range of ranges ?
Range to what targets ?

 

[Blue Scallop]

What range of ranges ?
Range to what targets ?

1 to 50 meters.
or 50 meters to 100 meters.
What targets can't reflect back?

 

[Baluncore]

What targets can't reflect back?

Some wavelength will always reflect back. Even a black body will get hot when you hit it with an IR laser.
An efficient diagonal “front surface mirror” would be a difficult target. You could not see it to get a correct range. But you could fire a pellet of reflective paint along the boreline, then get a correct range on the mirror surface.

 

[berkeman]

1 to 50 meters.
or 50 meters to 100 meters.

Those are two very different dynamic ranges. 50:1 is harder to deal with than 2:1...

What is the application? What resolution do you want to achieve? And as aked already, what kind of targets do you want the range to? People? Walls? Vehicles?

 

[Blue Scallop]

Those are two very different dynamic ranges. 50:1 is harder to deal with than 2:1...

What do you mean 2:1.. 2 meters range only?

What is the application? What resolution do you want to achieve? And as aked already, what kind of targets do you want the range to? People? Walls? Vehicles?

Buildings to measure property & signboards extensions. Do you know of ranger finder where you can aim it at an angle up to a building and it can give you the distance by taking account the angle? Because sometimes there is no horizontal object to aim like upper signs and billboards.

 

[berkeman]

What do you mean 2:1.. 2 meters range only?

LOL, no. dynamic range means max divided by minimum. That goes directly into the accuracy calculations that you should be doing.

Buildings to measure property & signboards extensions. Do you know of ranger finder where you can aim it at an angle up to a building and it can give you the distance by taking account the angle? Because sometimes there is no horizontal object to aim like upper signs and billboards.

If you can't get a reliable reflection (of light, radar, ultrasound, etc.), then your next best technique is probably optical
triangulation. Have you looked into optical triangulation yet? It is commonly used in animal hunting range finding applications, for example...

 

[berkeman]

Like this...

http://www.bowhunter.com/wp-content/blogs.dir/3/files/new-rangefinders-for-2013/01_bushnell.jpg

 

[Baluncore]

Cheap laser range finders, (less than US$50), are available for distances up to about 100 metres. The Pythagoras mode requires a horizontal range to the foot of the wall, which is why they have a bubble level built in.

Expensive laser range finders now have a two axis accelerometer so they can measure elevation angle. They do Pythagoras without a horizontal range to the wall.

Included here on pages 10 and 11 are the Pythagoras mode instructions for cheap type.
http://www.spoton.com.au/wp-content/uploads/2014/06/Powerline-PLM70-Instruction-Manual.pdf