Distance measurement by beating a varying test signal with reference signal having absolute frequency value predetermined with a specified accuracy
US9506739B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 2013 |
| Grant date | Nov 29, 2016 |
| Priority date | — |
| Expiry date | Sep 14, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/34
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method determines a distance with a specified accuracy. The method transmits to an interferometer a test signal oscillating with a test frequency and receives, in response to the transmitting, an interferometric signal formed by interfering the test signal with a delayed signal produced by delaying a copy of the test signal over the distance equal to a path length difference in the interferometer. The test frequency is varying such that the test signal oscillates with different values of the test frequency. The method determines at least two values of the test frequency corresponding to particular values of the interferometric signal by beating the test signal with a reference signal having a reference frequency, wherein a value of the reference frequency is an absolute value predetermined with the specified accuracy. The method determines the distance using the two values of the test frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.