Boffins in the UK have succeeded in refining global positioning satellite (GPS) technology so that it can locate positions to within half a centimetre. A report in today's The London Evening Standard said that scientists have used mathematical formulae to refine GPS, allowing it to be used to monitor micro-movements. The newspaper said that Professor Paul Cross, at University College, London, announced the breakthrough at the British Association Science Festival. He said that uses included the exact positioning of engineering projects, weather forecasting and other geological surveys. The technology could also make GPS a practical way of assisting blind people. ®