Testing was done by using ridge lift.

The rising air is due to thermals, ridge lift or other meteorological features.

Parlick is a popular venue for foot-launched gliders, because it produces good ridge lift in an unusually wide variety of wind directions.

Once pilots learned to exploit ridge lift and thermals, flights could be extended further.

In this way a gliding object can gain additional potential energy from sources such as thermals and ridge lift.

The lift is thus a combination of ridge lift and thermal.

Ground effect should not be confused with ridge lift when explaining how walkalong gliders stay up.

Walkalong gliders are sustained and controlled in the ridge lift produced by the moving paddle.

Speed to fly is a principle used by soaring pilots when flying between sources of lift, usually thermals, ridge lift and wave.

Once launched sailplanes try to gain height using thermals, ridge lift, lee waves or convergence zones and can remain airborne for hours.