Simultaneous Transmission of a Frequency Reference and a Time Code Over a Single Optical Fiber

摘要

The Apollo communications station is located at the JPL/NASA Deep Space Communications Complex at Goldstone California. It supports the manned Shuttle flights and Earth-orbiting scientific and communications satellites. This station needs precise frequency and timing references to perform its various tasks. In the past the station used a local Cesium clock to keep track of time which was established with a Loran-C receiver. The station's frequency and timing system has recently been upgraded to improve accuracy and reliability. In the new configuration, a 5 MHz frequency reference and a NASA 36-Bit time code are provided to the station from a central frequency and timing facility located 10 kilometers away. Both signals are transmitted from the frequency and timing facility to the Apollo station over a single optical fiber using a slightly modified commercial fiber optic link. This paper describes this dual channel fiber optic transmission system and gives its performance.