Estimating aircraft altitude for automatic landing - makes estimate from two independent measurements from inertial reference signal whose magnitudes are compared and weighted, chosen result is integrated to obtain estimate

摘要

An estimate(Z) of the aircraft's altitude, from at least two independent measurements(Z1, Z2) of the altitude is carried out for the aircraft which has at least an inertial reference system(IRS). A signal(Zi1) or (Zi2) representing a derived altitude taken from the inertial reference system(IRS), together with two other independent altitude measurements(Z1, Z2) of the same order, are submitted to a vote. An integrating operation is carried out so as to obtain the altitude estimate. The signal(Zi1) represents the vertical speed of the aircraft or first order of altitude and the signal(Zi2) represents the vertical acceleration of the aircraft or second order of altitude. ADVANTAGE - Is simple and effective and provides improved performance for automatic landing aids.