By Ian Hutchings*
Early years of Scott Base
This radio station at Scott Base was initially installed to support the ongoing research work on the continent run by the then DSIR although it is now run by Antarctica NZ.
The base was established in 1957 and Post Office support was known to be present from at least as early at 1960, and possibly earlier.
The Post Office provided two forms of personnel, a “winter over” technician, and a “summer season” technician. Additional staff were deployed as required for the summer.
Initially they were AM DSB services, but by the late 1960s these links became single sideband, with improved performance. Scheduled times were typically set for an hour or two a day, and pre-booked telephone calls were made as necessary.
There were also radio links (HF or MF) from Scott Base to support field parties and more remote sites such as Vanda.
The progress of technology
A major change occurred in 1990 when a satellite earth station (SES) was planned to enable communications via the Intelsat system with the SES at Warkworth, New Zealand. This facilitated multiple circuits and allowed much greater automation of calls on the basis of a continuous service. The 9m diameter antenna is located at Arrival Heights, a few kilometres from Scott Base, and is housed in a weatherproof geodesic dome. Cables connect the SES to Scott Base.
The Scott Base SES was innovative in that the site gave the antennae a very low angle of elevation (about 3 degrees) to the Intelsat satellite at 174 degrees east. This was below the Intelsat approved parameters of no less than 5 degrees. However, despite the low angle and greater percentage of the propagation path being in the more variable earth’s atmosphere, the system was tested and installed successfully in 1991.
At that stage the HF system to New Zealand was only required as a back-up in case of system failure. In due course the stations at Makara and Himatangi were closed, with Scott Base using facilities at the United States McMurdo base as a back-up.
One significant failure, which caused a prolonged outage, was the total failure of the Intelsat IS 804 satellite itself (at 174 deg. East) in January 2005. This disrupted Scott Base communications for some weeks as it was necessary to use capacity on a New Skies satellite at a different orbital location and with a different transmission polarity. A slightly lower elevation angle was required, and some additional waveguide parts were urgently sent to Scott Base to facilitate use of the required transmission polarity.
The system is now operated by Spark and forms part of the New Zealand telephone network. There is significant use of the system for data transfer associated with the science programmes. There is also a good cooperative arrangement with the US station at McMurdo, which means that alternative circuit routing is possible if serious equipment failure occurs.
* Ian Hutchings trained as a radio technician with the New Zealand Post Office in 1965, and worked on a variety of radio installations before obtaining an engineering degree in 1971 and moving to the Wellington Regional Engineers Office He later moved to POHQ and was subsequently Manager, Radio Spectrum Policy under a succession of government ministries. He retired in 2015 and holds the amateur radio callsign ZL2HUT.