Missing plane: How did a UK firm track the plane?

It has been announced that the missing flight MH370 crashed in the southern Indian Ocean - with information based on analysis from British satellite firm Inmarsat.

They were able to work out the flight went south after comparing previous Malaysian Airlines Boeing 777 flights' satellite data with flight MH370.

Inmarsat's senior vice president for external affairs, Chris McLaughlin, told the BBC's Richard Westcott that the firm studied electronic "pings" sent from the plane.