A software package has been developed to measure, monitor, and archive the performance of timing signals distributed in the NASA Deep Space Network. Timing signals are generated from a central master clock and distributed to over 100 users at distances up to 30 kilometers. The time offset due to internal distribution delays and time jitter with respect to the central master clock are critical for successful spacecraft navigation, radio science, and very long baseline interferometry (VLBI) applications. The instrument controller and operator interface software is written in LabView and runs on the Linux operating system. The software controls a commercial multiplexer to switch 120 separate timing signals to measure offset and jitter with a time-interval counter referenced to the master clock. The offset of each channel is displayed in histogram form, and "out of specification" alarms are sent to a central complex monitor and control system. At any time, the measurement cycle of 120 signals can be interrupted for diagnostic tests on an individual channel. The instrument also routinely monitors and archives the longterm stability of all frequency standards or any other 1-pps source compared against the master clock. All data is stored and made available for remote access via network connection.
This program was developed by Steven Cole, Jorge Gonzalez, Jr., Malcolm Calhoun, and Robert Tjoelker of Caltech for NASA's Jet Propulsion Laboratory.
This software is available for commercial licensing. Please contact Don Hart of the California Institute of Technology at (818) 393- 3425. Refer to NPO-30483.
This Brief includes a Technical Support Package (TSP).
Time Analyzer For Time Synchronization and Monitor of the Deep Space Network
(reference NPO-30483) is currently available for download from the TSP library.
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Overview
The document presents a technical overview of a Multi-Purpose Time Analyzer and Monitor developed for the NASA Deep Space Network (DSN). Authored by a team from the Jet Propulsion Laboratory (JPL), the report details the design and functionality of an automated system that continuously measures and monitors distributed 1 pulse per second (1 pps) reference signals critical for time synchronization in deep space communications.
The Time Analyzer is engineered to assess the performance of each 1 pps signal relative to a station master clock, providing essential data on time offsets and jitter (standard deviation) for each measurement. The system is capable of monitoring approximately 100 pps channels per station, ensuring comprehensive oversight of timing signals. Additionally, it tracks the long-term stability of both primary and backup frequency standards by analyzing time offset data over a 24-hour period.
One of the key features of the Time Analyzer is its alarm system, which alerts station operators to any anomalies or conditions that fall outside specified parameters. This capability is crucial for maintaining the integrity of time synchronization, which is vital for the success of deep space missions.
The user interface for the Time Analyzer is developed using LabVIEW and operates on a LINUX platform, providing a robust and flexible environment for monitoring and data analysis. The document also includes details about the frequency standard detail window, which displays a histogram of the previous 100 time difference measurements for selected frequency standards, allowing operators to visualize and assess timing performance over time.
The report emphasizes the importance of precise time synchronization in deep space operations, as even minor discrepancies can lead to significant issues in spacecraft navigation and data collection. The development of this Time Analyzer represents a significant advancement in the capabilities of the DSN, enhancing the reliability and accuracy of timekeeping essential for successful space exploration.
Overall, the document serves as a technical support package for the Time Analyzer, outlining its purpose, functionality, and the critical role it plays in the NASA Deep Space Network, ultimately contributing to the success of various space missions.
