
Accession Number : AD0723977
Title : Collision Geometry Formulae and Application to Collision Warning Techniques.
Descriptive Note : Research and development technical rept.,
Corporate Author : ARMY ELECTRONICS COMMAND FORT MONMOUTH N J
Personal Author(s) : Musillo,Anthony
Report Date : MAR 1971
Pagination or Media Count : 39
Abstract : The paper discusses two dimensional collision geometry in which straight and nonaccelerated flight paths are assumed. A derivation of the time dependence of the range (R), relative velocity (dR/dt), and relative acceleration (2nd dR/dt) will be presented and the quantities expressed as a function of R. The time to collision (tau) will be discussed, also. These quantities are applied to realistic collision geometries based on present Army aircraft operations. Also, a discussion of relative velocity versus range curves with reference to tau min (where tau = dR/(dR/dt)) and constant range warning lines is given. These parameters are incorporated in present stateoftheart techniques such as the Doppler and range increment techniques. The former technique attempts to detect any change in the Doppler frequency when tau = tau min ( in this case, 15 seconds). A change in the Doppler frequency indicates a noncollision course. The range increment technique measures differences in ranges over small constant time intervals and uses these range changes to obtain tau. A sample error measurement analysis in one of the low range rate change situations gives an indication of the magnitude of the range error measurement. (Author)
Descriptors : (*ARMY AIRCRAFT, FLIGHT PATHS), (*FLIGHT PATHS, *AVIATION SAFETY), WARNING SYSTEMS, AVIATION ACCIDENTS, MISS DISTANCE, DOPPLER RADAR, RANGE FINDING, DIFFERENTIAL EQUATIONS, NUMERICAL ANALYSIS, NUMERICAL INTEGRATION, CURVE FITTING
Subject Categories : Aircraft
Distribution Statement : APPROVED FOR PUBLIC RELEASE