Patent ID: 6845304
Filing Date: 2005-01-18
Classification: G01C,G01S

Abstract:
1. An airplane guidance method involving an inertial reference system and a GPS landing system, the airplane guidance method comprising: converting position coordinates of an aircraft from the inertial reference system to runway, lateral, and vertical coordinates; calibrating runway distance and lateral distance based on the converted position coordinates from the inertial reference system using runway distance and lateral distance from the GPS landing system with a third-order calibration filter when the aircraft is below a first height above terrain; calibrating vertical distance based on the converted position coordinates from the inertial reference system using vertical distance from the GPS landing system with a second-order calibration filter when the aircraft is below the first height above terrain; and using the calibrated runway, lateral, and vertical distances for deviation computations when GPS signals are interrupted below a second height above terrain.