US PATENT SUBCLASS 342 / 399
.~.~.~ Tacan

Current as of: June, 1999
Click HD for Main Headings
Click for All Classes

Internet Version by PATENTEC © 1999      Terms of Use


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.~.~.~ Tacan {2}
400  DF  .~.~.~.~> Receiver only {1}
404  DF  .~.~.~.~> VOR {1}

DEFINITION

Classification: 342/399

TACAN:

(under subclass 398) Subject matter including a complete ultra-high-frequency polar coordinate (RHO-THETA) navigation system using pulse techniques, wherein the distance (RHO) function operates as distance measuring equipment (DME) and the bearing function is derived by rotating the ground transmitter antenna so as to obtain a rotating multiple pattern for coarse and fine bearing information.

(1) Note. A typical TACAN system is comprised of the following: (a) a parasitic antenna element rotating at 900 RPM, generating an amplitude-modulated pattern at 15HZ, with phase proportional to the bearing of the receiver, (b) nine other parasitic elements, also rotating at 900 RPM, generating a multilobe pattern at 135 HZ, to improve the bearing accuracy; and (c) Reference pulses at 15 and 135 HZ to which the above variable phase signals are compared in the receiver to establish its bearing.

SEE OR SEARCH CLASS

701, Data Processing: Vehicles, Navigation, and Relative Location,

218, forcomputer navigation apparatus using TACAN equipment.