Video report by ITV News reporter Lewis Vaughan Jones
Inmarsat is a British satellite company that helped analyse and calculate the route of missing Malaysia Airlines Flight MH370 from its control centre in London.
The firm's senior vice president for external affairs has told ITV News' Lewis Vaughan Jones that this is the first time the company has ever tried to locate a plane using such little information.
"It's completely unusual. Inmarsat's been doing the global maritime distress service for 34 years now," Chris McLaughlin said. "We were founded to do that - this is the first time we've ever been asked to try to find something with just a single signal once an hour."
For several hours after going missing the plane still gave off a signal, called a "ping."
Pings don't reveal a location on their own, but the experts at Inmarsat used the Doppler Effect - slight changes in the wave frequency as they hit the satellite - to work out how the plane must have been moving.
Inmarsat claims that the plane could have been fitted with a better tracking system to avoid these delays - even now they still can't pinpoint exact co-ordinates, so the search at sea will continue.