More ‘eyes in sky’

Press, 26 September 1980, Page 4

More ‘eyes in sky’

PA Wellington From today, meteorologists will be able to have access to information on New Zealand’s weather beamed from four satellites. The new receiving complex, at the Meteorological Office at Kelbum, was opened yesterday by the Minister of Transport (Mr McLachlan). On the roof of the office are the three new dish antennae, one of which is used for tracking the orbiting satellites. The rest of the receiving equipment is housed on the fourth floor of the building, and includes a computer able to handle the rapid flow of information. The information will be relayed from two stationary satellites — one orbiting at 36,000 km over Papua New Guinea and the other over the eastern Pacific — and two orbiting satellites, which

each pass over New Zealand twice a day.

The satellites’ sensors can detect visible, thermal, and microwave radiation. The receiving station can compose detailed pictures of cloud cover and distinguish snow, ice. or rain over the land. Temperature change with height and the temperatures of sea surface and clouds can be calculated. Amounts of water vapour, carbon dioxide, and ozone will also be determined The satellites were launched by the United States and Japan. The orbiting satellites, Tiros N and Noaa 6, give detailed “views” with a maximum resolution of Ikm. Tiros and its mate have on board very sophisticated sensors providing so much data that it must be transmitted to Earth in digital form at high speed — 660,000 “bits” a second.

The stationary satellites Gms and Goes-W, scan the Earth with cameras which respond to both visible light and invisible infra-red radiation, and so clouds can be seen even at night The satellites transmit these images to the ground for computer processing into more useful forms after which the products are sent back to the satellites to be re-broadcast to countries such as ours. Temperature data from satellite measurements is particularly valuable. It helps the meteorologist “see” the atmosphere in three-demen-sions in regions where there are few other measurements, often obtained at great cost. Not only will the weather forcastr benefit, but satellite measurements of sea temperature and surface water are of great interest to oceanologists, fisheries reasearchers and hydrologists.