Ciphering device improving the secrecy of the encoded replies of a secondary radar
US4145690A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1977 |
| Grant date | Mar 20, 1979 |
| Priority date | — |
| Expiry date | Aug 8, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/781
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A secondary radar system in which the transponder and central station possess for enciphering and deciphering complementary dispersive filters having expansion/compression factors of .theta..DELTA.F.sub.1, where .DELTA.F.sub.1 = 1/.DELTA..mu. is a measure of the spectral width of each reply pulse having a temporal width of .mu., .theta. being at least s .mu./.DELTA..mu., such that at least two adjacent pulses spaced s apart in the initial reply train are completely overlapped in the expanded reply. The application to secondary radar systems, especially of the IFF type, in order to improve considerably the secrecy of the link between an airborne transponder and the ground station.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.