1. Trajectory in today's air traffic

1.1 Air traffic management

The concept of air traffic, simplified to the extreme, can be described as follows: airspace users, mainly airlines, offer to connect airports. To do this, aircraft fly between these airports. However, several aircraft may simultaneously occupy the same portion of the sky (known as airspace), creating a potential risk of collision. To minimize this risk, it is essential to put in place a structure capable of organizing and monitoring traffic, while intervening on aircraft to maintain sufficient distance between them. Air traffic management brings together all the players, systems and measures needed to guarantee safe and efficient flights. It is based on the definition, optimization, coordination, analysis and modification of aircraft flight paths....