Height Detection From Top Down?

Hi Guys,

I have a client that is looking to detect the height of a mound of material (dirt, gravel, rocks, etc.). I have yet to find a sonic sensor that can do this accurately at a 25m mounting height.

Normally, we set a camera up at some set distance away to view from the side, but is there a way to look top-down and determine the height? The issue becomes that we would have to erect a tower and run power and data (or use wireless) if we go with the first option.

Thanks very much!

Sonic sensors are progressively imprecise because of the beam spread.

What about a laser distance sensor like this:

You could always put a camera on a Fat Max as well, though I'm not sure how they would last in continuous duty.

Only way I can think of that it would work top-down would be to use two cameras for a binocular view - once calibrated for angle and separation distance, distance from object to camera can be easily calculated.

...distance from object to camera can be easily calculated.

Calculated by what?

Tenth grade trigonometry.

Tenth graders cost ten bucks an hour.

What if...

Put Pole/Stick at front of camera (left or right side) with wide horizontal bars (any color) calibrated with relative height of the mound....

Interesting. Maybe a light from the opposite side casting a shadow on the stick to make it easier to read. Or a mirror?