Intensity modulation at two frequencies for interferometric measuring of distance
US9631921B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 2015 |
| Grant date | Apr 25, 2017 |
| Priority date | — |
| Expiry date | Apr 13, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/66
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for measuring a distance includes modulating the light beam at a first frequency, receiving a second beam by the optical detector to produce a first electrical signal having the first frequency and a first phase; modulating the light beam at a second frequency different than the first frequency; receiving the second beam by the optical detector to produce a second electrical signal having the second frequency and a second. After these steps, the retroreflector is moved while modulating the light beam continuously at the second frequency; and a first distance to the retroreflector is determined based at least in part on a the first and second frequencies and phases.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.