Identification of friend or foe (IFF) systems
US4862176A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 17, 1978 |
| Grant date | Aug 29, 1989 |
| Priority date | — |
| Expiry date | Feb 17, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/78
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The IFF system uses basic identification codes which are transmitted between an interrogator and a responder. The basic codes are chosen in dependence upon the time and position of the interrogator or responder at the time of choice. In one version of the system, the lifetime of a code is less than or equal to the propagation time of a radio signal for a given maximum range between the interrogator or responder. Interactive interrogation may also take place using codes chosen in the same way as the basic codes. Local information may also be transmitted between the interrogator and transponder. An example of apparatus for performing these operations transmits basic or other codes together with a time code defining the time of production of the basic or other codes. It is not essential to transmit a time code in some circumstances. Position and time information may be gained from an external communications system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.