Warkworth to beam into satellite network

Press, Volume CXI, Issue 32661, 17 July 1971, Page 1

Warkworth to beam into satellite network

New Zealand will become an active member of the 79-nation consortium Intelsat by beaming into the Pacific satellite network this evening. The Postmaster-General (Mr McCready) will open the satellite ground station at Warkworth—New Zealand’s most sophisticated piece of communications equipment.

’ The station will be the 1 fifty-fifth of 90 planned 1 to be working throughout the world by the end of this year. [ The primary purpose of the > station is to provide international telephone Units be--1 tween New Zealand and the j rest of the world- The receiv- . ing and transmitting nerve is i the lOOft-diameter dish which 1 towers above the surround- , ing pastures of Warkworth. I The dish and terminal ; building are linked by micro- ■ wave to the Auckland International Exchange. 1 Theoretically, the operation of the system is simple. SIGNALS BOUNCED Telephone communications between New Zealand, Aus- ; tralia, the United States, and

. other Pacific Basin countries 1 with ground stations are ' flashed in the direction of the 1 satellite. 'Hie signals bounce ■ off the satellite and are ' picked up by the stations at which they are aimed. The satellite, named Intelsat 111, is 23,000 miles above I the Pacific Ocean rotating at I the same speed as the earth, , and thus appearing to be stat tfonary. , . The advantage of the system is that the communica- ! tion path is more stable than i radio links on earth. For most J of its journey to the satellite,

B the signal is unimpeded as it i 1 passes through outer space : where nothing exists to . change its character. ■ i . The satellite itself is no 1 more than an amplifier with frequency conversion to convert the signals going up and e down. The satellite is pow- [. ered by solar cells and pro- , vides a common amplifier for (he earth stations to work e together at the same time. ’- The satellite is restricted in s its capability because of its h low power, but the earth stations with their refinements and large parabolic antennae make up-for this. il When the beam from the . ground station reaches the , satellite, it is 50 miles wide ' —and very accurate tracking information is needed to cona trol the antenna and retain the satellite in the centre of the beam. DELICATELY TUNED s The Warkworth station can : transmit and receive simul-

taneously on its antenna, but the signal from the satellite is so low that the main receiving amplifier is delicately tuned to take the tiny signal.

1 While the station primarily : provides links for telephone 1 and telegraph traffic, it can ’ also transmit and receive ’ television pictures. ' New ’ Zealand, like some other ‘ countries, can only “see” the • Pacific satellite; which means 1 that it cannot operate direct 1 circuits bounded broadly by ' the west coast of the United 1 States, the west coast of Aus- ! tralia, and Thailand. Circuits to other countries, Britain for example, have to be extended by submarine cable. The opening of the station this evening will be the highlight of 83 years of development of radio communication in New Zealand. This development began with George Kemp’s first feeble success in using wireless communication between Wai-

roa and Gisborne in 1888—a year after Hertz discovered radio waves and eight years before Marconi demonstrated his invention in England. The Warkworth station will initially work to Intelsat 111 but will switch to Intelsat IV, a bigger satellite, to be sent into orbit lafer this year. From tonight, 30 international telephone circuits working to Australia, Hong Kong, and the United States will be in operation, and by the end of the year there will be 50. By 1976, there will be 200. The Warkworth station will be available immediately for exchanging either live or recorded television programmes in black and white or colour between New Zealand and any other country with an earth station.

The diagram illustrates the links New Zealand will have with other countries through the satellite.