Susan Smith has worked as an editor and writer in the technology industry for over 16 years. As an editor she has been responsible for the launch of a number of technology trade publications, both in print and online. Currently, Susan is the Editor of GISCafe and AECCafe, as well as those sites’ … More »
Inmarsat satellite data key in locating Malaysian Flight MH370
March 27th, 2014 by Susan Smith
Fragments of the missing Malaysia Airlines Flight MH370 are believed to have been found in the Indian Ocean, according to a press conference by Malaysian prime minister, Najib Razak. Inmarsat satellite data was instrumental in finding the debris. It is one of those events that baffles technologists, as the plane disappeared mysteriously two weeks ago, off the radar, and even now, the evidence is not conclusive that this debris belongs to the missing airliner.It is further proof that all the technology in the world cannot make sure of our safety and can also be manually turned off if someone has the desire to lose a plane.
Right after the aircraft disappeared, Inmarsat was involved in the search for the plane. Although the main aircraft communications addressing and reporting system (which would usually transmit the plane’s position) was turned off, one of Inmarsat’s satellites continued to pick up a series of automated hourly ‘pings’ from a terminal on the plane, which would normally be used to synchronize timing information.
Inmarsat analyzed these pings and was thereby was able to establish that MH370 continued to fly for at least five hours after the aircraft left Malaysian airspace, and that it had flown along one of two ‘corridors’ – one arcing north and the other south. This was shown in various news reports, but this information was given by the Doppler effect, the change in frequency due to the movement of a satellite in orbit. This gave two predicted paths for the flight – one northerly and one southerly route. Inmarsat engineers came up with this prediction which had never been done before, according to senior vice president of external affairs at Inmarsat, Chris McLaughlin. He said that the technology to track position and speed of the aircraft can be made available on planes for less than a dollar and hour. The plane was reportedly flying at a cruising height above 30,000 feet.
Although this information was given to Malaysian officials by March 12, the Malaysian government did not acknowledge it publicly until March 15, according to the Wall Street Journal. This delay in responding has been sharply criticized in the press and is thought to have contributed to a considerable loss of valuable time in recovering the lost aircraft.
Inmarsat’s engineers continued with their further analysis of the pings and came up with a much more detailed Doppler effect model for the northern and southern paths. They compared these models with the trajectory of other aircraft on similar routes and were able to confirm a matching between Inmarsat’s predicted southerly path with reading from other planes on that same route.
These pings from the satellite coupled with assumptions about the plane’s speed, made it possible for Australia and the US National Transportation Safety Board to narrow down the search area to just 3 per cent of the southern corridor on March 18th.
“We worked out where the last ping was, and we knew that the plane must have run out of fuel before the next automated ping, but we didn’t know what speed the aircraft was flying at – we assumed about 450 knots,” said McLaughlin. “We can’t know when the fuel actually ran out, we can’t know whether the plane plunged or glided, and we can’t know whether the plane at the end of the time in the air was flying more slowly because it was on fumes.”
The analysis was given to the UK Air Accidents Investigation Branch (AAIB) by Inmarsat this week. So far, the cause of the crash remains unknown.