The Drop-a-Ramp itself is a retractable fork sticking out straight from the main steering fork, parallel to the ground. This fork will be a meter+ long when fully extended and ~one and a half feet wide (a bit more than a third of a meter-ish). On the end of the fork will dangle a small uncurved ramp at a 30 degree angle to the ground. The ramp will be lightweight (probably plywood) and will have small rubber feet on its' bottom. On its upper corners will be attatched two lengths of fishing line that are just far enough apart to clear the pedals when the bike goes over the ramp.

The Drop-a-Ramp system will also have a slightly more complex section located near the deraileur, which will catch the fishing line once the bike is on the ground having cleared the obstacle, and hoist the ramp (probably using the spinning of the rear wheel) up to the resting point of the ramp, a rack positioned above the rear wheel, where it can later be loaded onto the dropping fork once more.

I have jumped off of a similar ramp everyday for years and have gotten about a meter-long jump in the air and a foot-high jump vertically.