Patent ID: 8416100

Claim:
A method for onboard monitoring of a horizontal position of an aircraft taxiing on the ground during an airport navigation, comprising the steps of: determining said horizontal position in part by determining first current height positions of the aircraft, wherein said first current height positions are repetitively determined over a first duration by an onboard positioning device that receives aircraft position information from an associated receiver that cooperates with a satellite positioning system, wherein the following steps are carried out automatically and repeatedly by an onboard monitoring device: a) repeatedly measuring second current height positions using at least one onboard altimeter for a second duration which is less than or equal to said first duration; b) calculating, using the second current height positions measured in step a), a plurality of second height differences which correspond to the respective differences between two successively measured second current height positions; c) comparing each of the calculated second height differences with a predetermined threshold value which depends at least on characteristics of said altimeter; d) calculating a first height difference which corresponds to a difference between said repetitively determined first current height positions determined by said onboard positioning device; e) comparing the first height difference with said threshold value; and f) emitting a warning signal which signals a problem with the reliability of said monitored horizontal position of said taxiing aircraft, in the event none of said second height differences is greater than said threshold value, but said first height difference is greater than said threshold value.