Patent ID: 6564149
Filing Date: 2003-05-13
Classification: G01S,G08G

Abstract:
A method of determining conflicting flight paths between a first airborne vehicle and a second airborne vehicle, the vehicles being adapted to be airborne above the earth, the earth being shaped as an oblate spheroid having a curvature, said method comprising:determining a position and a velocity vector for each of the first airborne vehicle and the second airborne vehicle; defining a cylindrical volume about the first airborne vehicle, the first airborne vehicle being centrally disposed therein; determining a separation distance between the first airborne vehicle and the second airborne vehicle at a selected time, the separation distance being at least partially determined from the position and the velocity vector of each vehicle and being adjusted with respect to the curvature of the earth using a great circle earth model; determining an accuracy factor for the position of each vehicle; modifying the separation distance by the accuracy factor; and determining whether the modified separation distance is within the cylindrical volume about the first airborne vehicle during a time range so as to determine whether conflicting flight paths exist between the first airborne vehicle and the second airborne vehicle.