GPS used to improve weather forecasts

Posted by Kate Taylor

Australian scientists are employing GPS to make weather forecasting more accurate, with a new type of temperature profile observation.

Researchers at RMIT University’s SPACE Research Centre and the Bureau of Meteorology have found that data from GPS and low earth orbit satellites can improve real-time observations and help cross-calibration of instruments.

"We are actually able to measure the amount of bending in the GPS beam as it passes through the atmosphere," says RMIT adjunct professor John Le Marshall.

"We can then use that knowledge to more accurately measure atmospheric temperatures and use this to improve temperature fields and calibrate other satellite readings. This extra information, in the data-sparse southern hemisphere, is now making our forecasts more accurate."

Already, he says, the Australian Bureau of Meteorology is delivering forecasts of the same accuracy 10 hours earlier.

Professor Kefei Zhang, Director of the RMIT SPACE Research Centre, says that using GPS for positioning, navigation and timing (PNT) provides a low-cost, powerful means of precise measurement.

"Weather forecasting is dependent on accurate observations of the atmosphere surrounding the whole planet, but there is a significant lack of ground-based meteorological observation stations," he says.

"That and the shortage of accurate surface level data from over the world’s oceans and polar regions limits the reliability of climate and weather predictions. GPS can fill that gap. It’s revolutionary technology. It’s the missing link."