Patent ID: 6239745
Filing Date: 2001-05-29
Classification: G01S

Abstract:
A global navigation satellite system (GNSS) landing system (GLS) for use in an aircraft preparing to land on a runway, the GLS comprising:a GNSS antenna adapted to receive GNSS positioning signals from a plurality of GNSS satellites;position determining circuitry coupled to the GNSS antenna and adapted to determine a position of the aircraft as a function of the received GNSS positioning signals; andvertical deviation computation circuitry coupled to the position determining circuitry and adapted to calculate an angular vertical deviation .alpha..sub.v from a glide slope of the aircraft as a function of a total horizontal distance between the aircraft and a GLS elevation reference point (GERP) using the relationship:[u.sub.lat.multidot..DELTA.r].sup.2 +[u.sub.rw.multidot..DELTA.r].sup.2 +Lwhere u.sub.rw is a vector which extends from a reference datum point (RDP) toward a flight path alignment point (FPAP) co-linear with the center line of the runway, where u.sub.lat is a vector which extends from the RDP in a direction perpendicular to vector u.sub.rw, and where .DELTA.r is a vector extending from a glide path intercept point (GPIP) on the center line of the runway toward a guidance control point (GCP) of the aircraft;wherein the GERP is offset laterally from a center line of the runway.