Time comparison system, time comparison device, and time comparison method
US11695473B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 2020 |
| Grant date | Jul 4, 2023 |
| Priority date | — |
| Expiry date | Aug 11, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/0075
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
[Problem] To determine a time difference between clocks which, for example, are placed far apart from each other with high accuracy at low cost.[Solution] In a time comparison system 20, an intermediate station 21 disperses a single optical signal 21c in the spatial region using the optical complex amplitude modulation to simultaneously transmit the optical signal 21c to a plurality of comparative stations 22 and 23 apart from each other. The intermediate station 21 transmits the optical signal 21c while changing the transmission angle using phase modulation, performs intensity scanning for the reflected light c1 of the optical signal 21c, and detects the peak intensity to determine the directions of the comparative stations 22 and 23. The reflected light c1 of the optical signal 21c transmitted to the comparative stations 22 and 23 of which the direction have been determined, is detected to determine a round-trip propagation delay time between the intermediate station 21 and each of the comparative stations 22 and 23. The difference calculation unit 25 calculates a sum of time difference between each of times to and tb associated with the comparative stations 22 and 23 and the tim…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.