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A phase‐coherent link via synchronous satellite developed for very long baseline radio interferometry
Author(s) -
Knowles S. H.,
Waltman W. B.,
Yen J. L.,
Galt J.,
Fort D. N.,
Can W. H.,
Davidson D.,
Petrachenko W.,
Popelar J.
Publication year - 1982
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs017i006p01661
Subject(s) - interferometry , phase (matter) , very long baseline interferometry , satellite , geodetic datum , remote sensing , link (geometry) , transmission (telecommunications) , geodesy , physics , baseline (sea) , stability (learning theory) , optics , computer science , telecommunications , geology , astronomy , computer network , oceanography , quantum mechanics , machine learning
A high‐precision, phase coherent link between remote interferometer stations has been developed and has been utilized in a transcontinental radio interferometer to assess the feasibility of improved astrometric and geodetic measurements. A dual‐tone transmission method effectively cancels most phase‐degrading effects. An experimental Allen variance curve indicates that stability of 1 × 10 −13 was achieved over a 1‐hour period; the slope of the Allen variance curve was close to − 1 for all time intervals up to 24 hours, indicating that the link is truly phase stable at frequencies of less than 1 GHz. Changes in the link path were measured with an accuracy of 300 ps, corresponding to 10 cm, over periods of several hours.