An Operational TWSTT Monitoring System
Abstract
The U.S. Naval Observatory (USNO) Time Service (TS) uses the AOA TWT-100 Atlantis Modem for its most important Two-Way Satellite Time Transfer (TWSTT) applications. A method was devised to measure delay changes due to hardware failures in an operational monitoring system. The VSAT on the Roof (VSR) of building 78 is a 1.8-meter dish using a SKYDATA RF unit and is used as the primary operational earth station for TWSTT with the USNO Alternate Master Clock (AMC) located at Falcon AFB, Colorado and for other stations. The Mobile Earth Station (MES) monitors the VSR performance by making six experiments per day. A second 1.8-meter VSat on the Other roof (VSO) is also used as a monitoring system. As long as the hardware remains in normal operating specifications, a constant time difference should result. The MES, VSR, and VSO are colocated with a common-clock reference, Master Clock 2 (MC2). Temperature measurements were taken using a thermocouple-based temperature measuring system. The thermocouple probes used to monitor the temperatures of each modem are located on top of the analog section. This paper presents the results of the estimation of time delay change with temperature difference between the modem in MES and a modem in the USNO TS earth station control room.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1997
- Accession Number
- ADA500801
Entities
People
- J. A. Deyoung
- P. Mai
Organizations
- United States Naval Observatory