US PATENT SUBCLASS 342 / 401
.~.~.~.~.~ VOR


Current as of: June, 1999
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342 /   HD   COMMUNICATIONS: DIRECTIVE RADIO WAVE SYSTEMS AND DEVICES (E.G., RADAR, RADIO NAVIGATION)

350  DF  DIRECTIVE {10}
385  DF  .~ Beacon or receiver {2}
386  DF  .~.~ With transmisson of bearing or position determinative signals {6}
399  DF  .~.~.~ Tacan {2}
400  DF  .~.~.~.~ Receiver only {1}
401.~.~.~.~.~ VOR {1}
402  DF  .~.~.~.~.~.~> Doppler {1}


DEFINITION

Classification: 342/401

VOR:

(under subclass 400) Subject matter including receiver means operating at VHF and providing radial lines of position in any direction as determined by comparing the phase of the beacon signal, which is a variable modulated signal, with that of a nondirectional reference modulated signal, within the receiver.

(1) Note. The variable signal has a phase relative to the reference signal which is different for each bearing point of the receiver from the beacon station.

(2) Note. A typical VOR system operates in the following manner: (a) The ground station (beacon) radiates a cardioid pattern that rotates at 30 CPS, generating a 30 Hz sine wave at the output of any airborne receiver; (b) The ground station also radiates and omni directional signal, modulated with a fixed 30 Hz reference tone; (c) The phase between the two 30 Hz tones varies directly with the bearing of the aircraft.

(3) Note. VOR us as abbreviation for VHF or omnirange.