Ingenicomm was chartered by NOAA to implement a multi-site distributed earth terminal at Barrow, Alaska and Fairbanks, Alaska.
The NOAA ground station in Fairbanks, Alaska has three 13-meter antennas that can be used to support spacecraft operations. As this is insufficient to support planned contact schedules at the site, it is necessary to use a secondary antenna array located at Barrow, Alaska.
Key Design Objectives
Reliably transport telemetry and command data between the NOAA sites at Barrow and Fairbanks
Provide data buffering and store-and-forward to compensate for the low bandwidth of the Barrow-Fairbanks link
Allow either Barrow or Fairbanks antenna assets to be used for a ground contact without affecting other components of the ground segment
Store and Forward
Two pairs of RS-422 data/clock signals are ingested by the system
The higher-priority channel is sent directly to the network interface for encapsulation and transmission
The lower-priority channel is sent to a buffer on disk while the high-priority channel is active
When the high-priority channel completes transmission, the low-priority channel is extracted from the buffer and transmitted
The path switching at Fairbanks is transparent to the FEP
The NOAA subsystems at other sites interface only with the Fairbanks FEP, not the antennas directly
The ground network can therefore treat the combination of Fairbanks and Barrow as a single logical earth terminal