Patent ID: 7853368

Claim:
A method performed by a computer to construct a low altitude flight trajectory to be followed by an aircraft, in particular a military transport plane, said flight trajectory comprising a lateral trajectory and a vertical trajectory, the method comprising: providing a terrain profile pertaining to a terrain to be overflown by the aircraft together with information pertaining to the aircraft and to its environment; constructing said lateral trajectory of the flight trajectory; and constructing said vertical trajectory of the flight trajectory over a profile section defined between two height maxima of said terrain profile by: displacing over said entire terrain profile a V-shaped construction profile, having two branches determined respectively by maximum angles of climb and of descent; and selecting a position of said construction profile, at which edges of said construction profile are tangential to said terrain profile, and no peak of said terrain profile crosses said construction profile, so that the position thus selected of the construction profile allows the construction profile to form the part of the vertical trajectory which is situated at the level of said profile section, wherein the two branches of the V-shaped construction profile join up according to a circular arc transition phase, and the method further comprises: setting a highest summit over the entire lateral computation trajectory as a first height maximum of the two height maxima; extracting the height maxima from the terrain profile from the highest summit, taking account of a minimum length of segments of the construction profile; topping the height maxima by circular arc transitions; sliding the construction profile by starting from a given height maximum topped by a transition circular arc, until the construction profile arrives in contact with a transition circular arc corresponding to a height maximum; and sliding the edges of the construction profile to be tangential with these circular arc transitions.