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Local oscillator distribution using a geostationary satelliteA satellite communication system suitable for distribution of local oscillator reference signals for a widely spaced microwave array has been developed and tested experimentally. The system uses a round-trip correction method of the satellite This experiment was carried out using Telstar-5, a commercial Ku-band geostationary satellite. For this initial experiment, both earth stations were located at the same site to facilitate direct comparison of the received signals. The local oscillator reference frequency was chosen to be 300MHz and was sent as the difference between two Ku-band tones. The residual error after applying the round trip correction has been measured to be better than 3psec for integration times ranging from 1 to 2000 seconds. For integration times greater then 500 seconds, the system outperforms a pair of hydrogen masers with the limitation believed to be ground-based equipment phase stability. The idea of distributing local oscillators using a geostationary satellite is not new; several researchers experimented with this technique in the eighties, but the achieved accuracy was 3 to 100 times worse than the present results. Since substantially and the performance of various components has improved. An important factor is the leasing of small amounts of satellite communication bandwidth. We lease three 100kHz bands at approximately one hundredth the cost of a full 36 MHz transponder. Further tests of the system using terminal separated by large distances and comparison tests with two hydrogen masers and radio interferometry is needed.
Document ID
20060043742
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
Bardin, Joseph
Weinreb, Sander
Bagri, Durga
Date Acquired
August 23, 2013
Publication Date
July 18, 2004
Meeting Information
Meeting: International Square Kilometer Array (SKA) Conference
Location: Pecticton, British Colombia
Country: Canada
Start Date: July 18, 2004
End Date: July 22, 2004
Distribution Limits
Public
Copyright
Other
Keywords
hydrogen maser
Local Oscillator (LO)
Two Way Time Transfer (TWTT)
distribution

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