Accession Number : AD0859554

Title :   Correlated Radionavigation Systems,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH

Personal Author(s) : Bogr, J.

Report Date : 30 JUN 1969

Pagination or Media Count : 13

Abstract : The most frequent application of correlation radio-navigational systems is in measuring actual altitudes of aircraft in flight, which is done by gauging time lapse between emitted and received radio signals. Such distance meters are composed of two sets of radar transmitters and receivers; one fixed on the ground transmits modulated signals and has a correlator to gauge time lapse. The second set acts as a beacon-relay, but for airborne radar the earth acts as reflector. Signal modulation and correlation function are analyzed with emphasis on time accuracy, and a formula is developed for mean quadratic deviation in altitude measurements. The conclusion is stated that correlative altimetering is most accurate in landing aircraft, much more reliable than the usual landing systems based on frequency modulated signals. The use of correlative radar altimeters in combination with white noise frequency modulation is discussed, with the conclusion that this system is no more complicated than present altimeters and its considerably more accurate at low altitudes.

Descriptors :   (*RADIO NAVIGATION, CORRELATORS), RADIO ALTIMETERS, RADIO EQUIPMENT, STATISTICAL FUNCTIONS, INTEGRATED SYSTEMS, CZECHOSLOVAKIA.

Subject Categories : Air Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE