A differential flat approach to trajectory noise assessment

The sustained growth of air transportation traffic along the last decades has induced increasing noise exposure for the areas surrounding large and medium airports. International and national regulations regarding noise exposure have been established by civil aviation authorities. So to meet the resulting noise constraints, new departure and arrival procedures have been established locally. The accuracy of the trajectory followed by a given aircraft depends on many parameters such as navigation and guidance systems and trajectory dispersion is a common phenomenon which should modify the expected performance with respect to noise exposure of airport neighborhood. Since the guidance flight dynamics present a differential flatness property, given the 4D trajectory to be followed by the aircraft, nominal control inputs which are characteristic of the generated and diffused noise, can be established. The generation of deviations from the nominal trajectory can be used to establish more realistic noise level curves at ground level. The proposed approach is illustrated in the case of an approach trajectory at Santos Dumont domestic airport.