Systems and Methods for Assuring the Accuracy of a Synthetic Runway Presentation

摘要

Automated systems and methods that utilize high-accuracy landing system data to correct the position of a synthetic runway presentation on a pilot display. This is achieved by first computing the “synthetic” lateral and vertical rectilinear deviations of the airplane from an ideal beam using the airplane's GPS position and barometric altitude, the runway location and orientation contained in an airborne database, and approach angle information. This synthetic deviation data is then compared to rectilinear deviation data computed by the computer system as received from a ground installation. The computer system is programmed to determine the differences between the ground-based and GPS-based rectilinear deviation data and then compute a corrected position vector using those differences. The position of the synthetic runway symbology on the pilot display is adjusted as a function of the corrected position vector.

主权项

1. A method for positioning a synthetic runway presentation on a display screen of a display unit as an airplane approaches a runway, comprising the following steps performed by an onboard computer system:
(a) computing first rectilinear deviation data representing successive estimated rectilinear deviations of the airplane from the desired flight path during the approach, the first rectilinear deviation data being computed based at least in part on airplane sensed angular deviation data from ground-based reference beams and airplane-to-runway distance data; (b) computing second rectilinear deviation data representing successive estimated rectilinear deviations of the airplane from the desired flight path during the approach, the second rectilinear deviation data being computed based at least in part on airplane latitude, longitude and altitude data and runway data; (c) computing a corrected position vector based at least in part on a difference between said first and second rectilinear deviation data; and (d) controlling a display unit to display a synthetic runway presentation having a position on the display screen that is a function of said corrected position vector.