Patent Document ID: 9342988
Application ID: 14586461
Patent Status: 1

Claim One:
1. A method for determining a linear terrain profile along a lateral approach trajectory of an airport, the method comprising: at a central processing unit (CPU) that is communicatively linked to a database and at least one memory: receiving measured values that are automatically stored in the at least one memory, wherein the measured values are automatically and repetitively measured on at least one aircraft during at least one flight of the aircraft along the lateral approach trajectory, during an approach to a landing runway of the airport, and wherein the measured values comprise a height of the aircraft relative to the ground measured using at least one onboard radio altimeter, a barometric altitude measured using at least one onboard barometric altimeter, a total air temperature and a Mach number of the aircraft measured using onboard sensors; automatically, after the flight of the aircraft and after receiving the measured values: repetitively, for each of a plurality of different distances relative to a threshold of the landing runway along the lateral approach trajectory: a) estimating, using the total air temperature, the Mach number and the barometric altitude, measured and stored in the at least one memory, a variation of the static temperature dependent on the altitude and a temperature on the ground; b) computing a geometric altitude, using the barometric altitude measured and stored in the at least one memory, as well as the variation of the static temperature and of the temperature on the ground, estimated in step a); c) computing a terrain height, by subtracting, from the geometric altitude computed in step b), the height measured by the radio altimeter and stored in the at least one memory; and for the set of the plurality of different distances relative to the threshold of the landing runway along the lateral approach trajectory: d) determining at least one auxiliary terrain profile from the set of terrain heights computed for the set of different distances; e) determining a one-dimensional terrain profile using at least the auxiliary terrain profile, the terrain profile representing the trend of the terrain height as a function of the distance relative to the threshold of the landing runway, the terrain height being defined relative to a reference altitude corresponding to that of the threshold of the landing runway; and f) storing, in the database, the terrain profile determined in step e).