Traffic radar system
US4335382A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1980 |
| Grant date | Jun 15, 1982 |
| Priority date | — |
| Expiry date | Mar 10, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/92
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A traffic radar system is provided in which the speed of a target vehicle is determined by measuring the difference in frequency between a component of a doppler signal which has a frequency proportional to the relative speed of the target vehicle and a moving patrol vehicle and a reference signal having a frequency proportional to the speed of the patrol vehicle. The reference signal is developed from a tachometer device which generates a periodic signal having a frequency proportional to the rotational speed of a vehicle wheel and phase-locked loop arrangements including adjustable dividers are provided for locking an oscillator to the tachometer signal and generating a reference signal at a frequency proportional to the actual speed of the patrol vehicle. For calibration, a component of the doppler signal produced from reflections from stationary objects is used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.