Homebuilt Rov Forum

I know light can travel in a vacuum, but I don't think the tool is normally used in a vacuum. lol. We would have a computer do these calculations. We will have a color camera on board so I think we will be able to see the laser and aim it at the PVC.

Cool. How do you plan to interface the computer with the laser? As for the tool being used in a vacuum, couldn't the same be said for it being used underwater?

Touché. We will probably either look at the reading with a camera, unless we can hack it and send it over an Arduino as an input.

standard speed of light = c ( in a vacuum )
in air the speed of light is almost the same as in a vacuum ( = c / 1.0003 )
in water the speed of light is c / 1.333

most measuring tools are designed for working in air, so when use in water you have to recalculate the distance


cool diy projects on a laser rangefinder:

http://hackedgadgets.com/2010/11/24/laser-range-finder-build/
http://diydrones.com/profiles/blogs/30-laser-rangefinder

will a kinect work underwater?

I'm sure it does, but to get correct dimensions/measurements for underwater use I'm sure tons of work would have to be done on the software side. I also think it might be a bit much overkill, unless maybe you go fishing with your ROV or something.

I guess it really depends what your measuring, what if you just carried a pair of 1"x1" maker cubes, laid them next to what your trying to measure and then calculated whatever distance you needed from a still shot? Or like someone said, a ruler, you lay the ruler in parallel to the pipe or whatever your measuring, then stand back and take a picture? Thats some basic math right there, you could probably have a kid crunching those numbers on a pad and paper once you took a picture for him.

You just need a fixed reference to measure from. It would be cheap at least.

Hi ltdcruze,

You might like to look at the 'Parallax' Laser Range Finder.

http://www.parallax.com/

or

youtube video "very cheap homemade cam range finder (LIDAR) programed in visual c++ 2008 express"

Max

If you're just trying to measure the size of an object under water you can try using two simple laser pointers.

The pointers would be attached to your frame so that they are exactly parallel to each other and say a foot apart. You then can shine the lasers on the object and the then estimate the over all size of the object by looking at the distance of the two laser dots compared to the whole object.

-Steve

Two Lazers mounted in perfect distance apart would be an idea. I saw an ROV that look like a cube with a setup like that. AC-ROV