Accession Number : ADD005966

Title :   Measuring the Speed of an Aircraft.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Graewe,Eberhard ; Krajeweski,Siegfried

Report Date : 13 Mar 1979

Pagination or Media Count : 6

Abstract : A continuous wave ultrasonic wave transmitter transmits modulated waves in two opposite directions being intercepted by a forward receiver and an aft receiver. The received signals are demodulated and the relative phase is used to obtain a speed reading. The wave length of the modulator signal must be larger than the two, preferably equal transmitter-to-receiver spacings. A similar but orthogonally arranged receiver system permits acquisition of a speed vector. Different modulation frequencies are to be used for different speed ranges; all these frequencies are transmitted simultaneously and selection of the desired one is made in the processing circuit only. (Author)

Descriptors :   Patents, *Airspeed, *Measuring instruments, Ultrasonics, Continuous waves, Signal processing, Velocity, Flight speeds

Subject Categories : Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE