Vehicle identification system using radar and acoustic information
US4635058A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 14, 1983 |
| Grant date | Jan 6, 1987 |
| Priority date | — |
| Expiry date | Dec 14, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/86
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A vehicle identification system includes a doppler radar producing a doppler frequency signal having noise components and having a value f.sub.D corresponding to the speed of the vehicle to be identified and a doppler frequency having a value X.multidot.f.sub.D corresponding to the speed of the vehicle propelling means, each doppler frequency being modulated by signals corresponding to the movements made by individual elements of the vehicle propelling means. The doppler signal is passed through first and second adjustable filters adjusted to pass f.sub.D and x.multidot.f.sub.D respectively and sidebands relating to the modulating signal. Amplitude detectors coupled to the outputs of the two filters remove the doppler frequencies leaving the modulating signals relating to the movement of the vehicle elements. The modulating signals are applied to an adjustable commutating filter adjusted to frequency by a signal corresponding to frequency f.sub.D. The output signal from the commutating filter represents sounds made by the vehicle individual elements by which one can identify the vehicle as to type.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.