Frequency tracking method and apparatus, and Doppler velocity meter using the same
US5696578A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 1993 |
| Grant date | Dec 9, 1997 |
| Priority date | — |
| Expiry date | May 13, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S7/4917
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention has as its object to provide a frequency tracking method, a frequency control apparatus (tracking apparatus) using this method, and a Doppler velocity meter using the same, which easily and quickly allow the center frequency of a band pass filter to coincide with the frequency of an input signal even when an input signal suffers from a large level drift. A tracking method for a center frequency of a band-pass filter relates to a method including the deviation information detection step of detecting deviation information of the frequency of a signal to be input to the band-pass filter or a signal output from the band-pass filter with respect to the center frequency of the band-pass filter, the deviation information detection step including at least the step of detecting the deviation direction, and the changing step of changing the center frequency of the band-pass filter on the basis of a detection result in the detection step of detecting the deviation information including the deviation direction, thereby adjusting the center frequency of the band-pass filter to coincide with the frequency of a signal to be filtered through the band-pass filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.