Accession Number : ADD006781

Title :   Aircraft Orientation Determining Means.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Lewis,Bernard L

Report Date : 11 Sep 1979

Pagination or Media Count : 6

Abstract : The invention concerns a system for measuring, in conjunction with a GCA radar, the crab angle of an aircraft which is making its landing approach above a runway just prior to touchdown. Two doppler radars are placed, one on each side of the runway at equal spacings from the center line of the runway, with their antennas facing each other. The doppler radars function at very nearly the same frequency. The average doppler frequency of the echo received by each radar is determined and the frequencies are substracted from each other. The difference in doppler frequency and the ground velocity of the aircraft are coupled to a computer which solves an equation to provide the value of the crab angle of the aircraft. The result can be radioed to the aircraft so that an adjustment in yaw can be made to zero the crab angle before touch-down.

Descriptors :   *Patents, *Aircraft landings, *Doppler radar, *Orientation(Direction), Inventions, Angles, Measurement, Equations, Runways

Subject Categories : Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE