I am assuming that its not autonomous and the angle/thrust is either pre-programmed for the demo or is human operator controlled.

I'm thinking just basic geometry and some rangefinders and other sensors. It needs to know how high off the ground its rangefinder is, and how far away the base of the target is. Once it knows that, it's some basic arithmetic to determine the height of its target landing area. Set a trajectory, charge for both the distance and height (and possibly to compensate for wind) and you're done.

There's some implementation subtleties I'm sure, especially considering your launch surface may vary, but that's the gist of it.

> Jumps of 1-8 m heights are user selectable

> Laser-based ranging to guide launch

(http://www.bostondynamics.com/img/SandFlea%20Datasheet%20v1_...)