Salt lake tests out latest imaging satellite

17 Jun 2002

NASA's latest satellite imaging technology has been put through its paces, but from the ground in the middle of an Australian salt lake.

The EO-1 satellite, which was launched in November, houses the Hyperion imaging equipment that records more detailed information about the Earth's surface than previous satellite instruments. However, before the instrument can perform successfully, it needs to be calibrated carefully to make sure that it is seeing from space what should be seen from the ground.

A team from CSIRO's Earth Observation Centre in Australia went to Lake Frome (which is a salt lake 500 km north of Adelaide) because it has a bright, white, uniform surface. Hyperion records the brightness of the Earth in 220 different spectral bands. Other Earth-observation satellites typically detect a maximum of only seven spectral bands, according to Dr David Jupp from CSIRO.

The team measured the exact brightness of the salt in the same 220 bands that were used by Hyperion. Other instruments on the shore measured the amounts of water vapour and dust in the atmosphere, and balloon soundings analysed the atmosphere above the lake. The results will be compared with the Hyperion readings and the effect of the atmosphere can be subtracted.

Over the next year, the instrument will be tested in other extreme landscapes, such as the darkness of the deep waters of Lake Argyle in Western Australia.

Project information: http://www.eoc.csiro.au/hswww/