Laser Rangefinder

Determining altitude is trickier than it may seem. An IR range finder will not work due to the heat of the engines and ultrasonic wont work because of the noise. The only real options left are Radar or a laser.

I have looked lots of  laser range finders but they are all either expensive or not suited to my application. There are plenty of cheap "laser tape measures" but all display the distance on a built-in screen and attempts by others to modify them  have been limited to hacking the segment display. Parallax make a reasonable priced sensor but it uses triangulation (with a camera) instead of time of flight and I think that the cloudy exhaust might interfere and also only works at 1Hz. There are heaps of industrial ones but none under 1K$.

Today I came across this:

Its a board  by Porcupine Electronics that connects to a fluke 411D (laser range finder) and outputs the distance data over USB and serial.:

The display and keyboard is removed and replaced

Apparently it can output at 10Hz with +- 3mm accuracy from 10cm to 30m. Also it will be quite light as the housing can be removed and the electronics themselves wont weigh much.