National_Catalogues: Stabilization of a Fiber-Optic Link Using a Temperature-Controlled Fiber Segment

Title: Stabilization of a Fiber-Optic Link Using a Temperature-Controlled Fiber Segment
Identifier: ADA500810
STOAbstractExternal: The Deep Space Network (DSN) of the National Aeronautics and Space Administration (NASA) is operated by the Jet Propulsion Laboratory (JPL), California Institute of Technology. The DSN uses fiber optics to distribute frequency and time to remote sites that may be as far as 32 kilometers from the Signal Processing Center (SPC) which contains the frequency standards and master clock. The fiber-optic cables are buried 1.5 meters underground. At this depth, the only apparent temperature variations are those due to the annual cycle, having a pseudo-sinusoidal behavior with a 1-year period and a diurnal cycle that is greatly reduced due to the insulation of the earth. Some variation is also caused by the air-conditioning cycling of the fiber-optic cable temperature in the plena of the buildings and the lengths of cable that are in manhole vaults along the run. The resulting stability of the references at the remote site is well within the requirements of the DSN. However, the radio science requirements for the Cassini mission are much more stringent than the DSN requirements and the existing performance does not meet these requirements. The particular antennae (DSS-25) to be used for the 32 GHz portion of the Cassini radio science mission is 17 kilometers from the main control center and the apparent temperature variation (as measured by the delay variation) is 11 deg C peak to peak over the annual cycle. By inserting a temperature-controlled section of fiber-optic cable whose temperature is controlled in such a manner as to force the total delay to be constant, the annual variation (and small variations due to storm fronts passing through the area) can be reduced to a negligible amount. The length of this inserted fiber-optic section is > 3.74 kilometers and the temperature variation of this section over the year is 50 deg C. Details of the design and preliminary results are given.

STOAuthorExternal: CALIFORNIA INST OF TECHNOLOGY PASADENA JET PROPULSION LAB Sydnor, Richard L., Calhoun, Malcolm, Lopez, Jerry, Diener, William
STOClassificationExternal: N
STOKeywordsExternal: CASSINI SATELLITES, DEEP SPACE NETWORK, TIME DELAY, PRECISE TIME, DSS-25 ANTENNAE
STOPublisher: USA
Language: English
STOReportSource: http://www.dtic.mil/docs/citations/ADA500810
Published: 12/1/1996

Created at 11/9/2016 3:26 PM by System Account
Last modified at 11/9/2016 3:26 PM by System Account
 
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