Abstract
For an unmanned autonomous vehicle, it is important to estimate its position and attitude precisely. Pressure altitude is effective to improve the accuracy in state estimation. It is known that the pressure altitude is affected by ground effect. In case of helicopters with a single rotor, the ground effect is supposed to appear when the altitude is lower than the diameter of the rotor. The helicopters equipped with multi rotors in the same horizontal plane, it is supposed that ground effect would appear higher altitude than the diameter of the rotors. Using quadrotor helicopters, experimental data is collected, which explicit the impact of the ground effect.
