Accuracy of GPS Time Transfer Verified by Closure Around the World
Abstract
The precision of time transfer over intercontinental distances by the GPS common-view method, using measurements of ionospheric delays, precise ephemerides provided by the DMA and a consistent set of antenna coordinates, reaches 3-4 ns for a single 13-min measurement, and decreases to 2 ns when averaging several measurements over a period of one day. It is thought that even this level of precision can be bettered by improving the ionospheric measurements, the ephemerides of the satellites and the antenna coordinates. In the same conditions, an estimation of the accuracy is attained by using three intercontinental links encircling the Earth to establish a closure condition: The three independant time links should add to zero. We have computed such a closure condition over a period of thirteen months using data recorded at the Paris Observatory in Paris (France), at the Communications Research Laboratory in Tokyo (Japan) and at the National Institute for Standards and Technology in Boulder, Colorado (USA). The closure condition is verified to within a few nanoseconds but a bias, varying with time, can be detected.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1991
- Accession Number
- ADA512423
Entities
People
- Christoph Thomas
- G. Petit
- Wlodzimierz Lewandowski
Organizations
- International Bureau of Weights and Measures