Sector scan ADF system
US4317120A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 1979 |
| Grant date | Feb 23, 1982 |
| Priority date | — |
| Expiry date | Sep 24, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S3/54
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An automatic radio direction finding system having inputs for a circular array with a plurality of directional antennas, each being switched in sequence producing a directional pattern in azimuth. The combined RF signal is carried through the receiver as a normal AM modulated signal and the intermediate frequency output of the receiver is detected and the added modulation is recovered, filtered, and accumulated in such a manner that random signals will cancel and any repetitive signals will increase in amplitude and be stored. The vector information of this stored modulation, when decoded with respect to the phase of the original modulation, contains the actual bearing information. The signal is then averaged over several cycles and displayed on a numerical readout in degrees azimuth. The averaging techniques are employed to eliminate jitter in the last digit. A second display, a circular bar-graph, also uses averaging to remove jitter, and gives the operator a more instinctive feel for the tendencies of a changing bearing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.