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United States Patent | 5,070,334 |
Commissaire , et al. | December 3, 1991 |
A method for assisting terrestrial vehicle traffic involves equipping at least some vehicles with a radar system and a transponder capable of re-transmitting with selected frequency transposition any radar wave received within a predetermined frequency band. The radar system semi-continuously transmits the waves capable of measuring a distance over a range of several hundreds of meter, and the radar system receives the transposed echoes in order to carry out distance measurement thereon. It is also possible to provide certain bodies, not equipped with radar, with individual transponders which are different from those provided on vehicles.
Inventors: | Commissaire; Henri (Elancourt, FR), Pathier; Pierre (Biervres, FR), Sirven; Jacques (Versailles, FR) |
Assignee: |
Electronique Serge Dassault
(Saint-Cloud,
FR)
|
Appl. No.: | 07/490,308 |
Filed: | March 8, 1990 |
Mar 21, 1989 [FR] | 89 03700 | |||
Current U.S. Class: | 342/43 ; 342/125 |
Current International Class: | G01S 13/00 (20060101); G01S 13/84 (20060101); G01S 13/02 (20060101); G01S 013/80 () |
Field of Search: | 342/51,42-44,125 |
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2746776 | Apr., 1979 | DE | |||
2248517 | May., 1975 | FR | |||
2353863 | Dec., 1977 | FR | |||
256294 | Oct., 1985 | FR | |||
IEEE, "Automatic Vehicle Identification Technology and Applications", pp. 285-291, May 1985.. |