Rafa brings up 30-0 in no time, his viciously-spinning forehand forcing Ferrer to return balls at head height.

BBC: Australian Open day 10 as it happened

By timing how long the signal takes to make the return trip, the instruments can determine differences in height.

BBC: Mapping Earth's surface in 3D

Siemens' president and chief executive Dr Heinreich von Pierer forecasts that the growth in IT will return, but they are unlikely to see levels of growth seen at the height of the boom.

BBC: US Secretary of State Colin Powell