Accurate Delay Calibration for Two-Way Time Transfer Earth Stations
Abstract
The most accurate clocks are using cesium beam frequency standards as their source of accuracy. The atomic time scale TAI is built from the SI seconds after adopting the definition of its origin. As a practical time scale close to the astronomic time, UTC has been introduced, which is equal to TAI, but kept in close agreement with universal time, by additional or subtraction of leap seconds. UTC and TAI are computed by the BIPM from the time comparison data of laboratory and commercial cesium clocks. The accuracy of comparing clocks all over the world has been: improved significantly by the use of the GPS common view method. This one way method is capable of precision around 8 ns and accuracies of about 30 ns if not deteriorated by Selective Availability measures. A further improvement can be realized by using two-way methods, as demonstrated in several experiments using groundstations at each clock site capable of reception and transmission. This paper addresses the calibration of the groundstations to achieve high accuracy in such two way time comparisons.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1989
- Accession Number
- ADA497822
Entities
People
- Gerrit De Jong