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Tuesday, May 27, 2014

MH370 satellite logs released, but redactions by Malaysian government will only fuel further conspiracy theories

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Malaysian authorities, working with British satellite company Inmarsat, has released 47 pages of satellite logs that were used to track flight MH370 to the southern Indian Ocean. The timing on this release is significant, as Australia today announced that the deep-sea search for flight MH370 has been postponed for three months, pending a complete bathymetric (topographical) map of 60,000 square kilometers of the seabed where MH370 is thought to have crashed. As the search for the missing plane moves into its eleventh week, we yet again have to wonder whether we are looking in the right place or not. With the release of the satellite logs, can we now check if Inmarsat is right about MH370′s final resting place?
Some 11 weeks ago, on March 8, Malaysia Airlines flight MH370, en route from Kuala Lumpur to Beijing, cut its radio ties and disappeared from radar screens forever. While we have tried to locate the plane’s signature in the radar logs of nearby countries, the only trace we have yet found are the satellite “pings” between the plane and the Inmarsat 4-F1 satellite above the Indian Ocean. Inmarsat used the Doppler effect to track the plane’s course to the south, using a technique that we previously covered in some depth.
A map showing the location of the Inmarsat satellite that received keepalive pings from MH370, and the plane's possible radius from that satellite, which led to the current search area in the Indian Ocean
A map showing the location of the Inmarsat satellite that received keepalive pings from MH370, and the plane’s possible radius from that satellite, which led to the current search area in the Indian Ocean [Image credit: Wikipedia]
Because this is the only data we have about MH370′s whereabouts, there has been a lot of pressure on the Malaysian government and Inmarsat to release the logs, so that they can be investigated and interrogated by third parties — primarily to check if Inmarsat got it right, but also to satisfy the conspiracy theorists who believe that foul play is afoot. Today, 47 pages of logging info has been released [PDF] — but unfortunately, they’re redacted, human-readable logs, not the raw data that was received by the ground station.Inmarsat and the Malaysian authorities say that all of the important data is there, and that the raw logs wouldn’t have been understandable. The company says the purpose of the release is transparency, not verification.
This continued coyness from the Brits, some 11 weeks after 239 people went missing, isn’t likely to quieten the conspiracy theorists. There are lots of gaps in the “readable summary,” ostensibly to remove extraneous info, but surely it should be up to the global community to decide what is and isn’t extraneous?
A snippet of Inmarsat satellite logs, showing a ground-to-air telephone call that went unanswered
A snippet of Inmarsat satellite logs, showing a ground-to-air telephone call that went unanswered
Still, the summarized logs are better than nothing — and, to Inmarsat’s credit, they are quite human readable. The first two pages of the PDF give you a pretty good grounding of what a satellite communications packet looks like in a log file, and how the company used the Doppler effect (burst frequency and burst timing offset) to track the plane. The document includes important timestamps, such as when the last ACARS message was transmitted. There’s also the curious inclusion of two ground-to-air telephony calls that went unanswered by the plane at 18:39 and 23:13 UTC.
Inmarsat 5-F1 and F2, huge communications satellites
Inmarsat’s communication satellites are huge. Shown here is the next-generation Inmarsat 5-F1, which is about the size and weight of a bus.
By all means, if you have the wherewithal to analyse Inmarsat’s data to see if MH370 actually landed in the southern Indian Ocean, please do.
In other news, the search of the ocean floor for debris of flight MH370 with the Blufin-21 AUV has been postponed for around three months. The Australian Transport Safety Bureau (ATSB) which is coordinating much of the search effort said that it would wait until a proper topographical (bathymetric) map of the area had been performed, before expending more resources. The Chinese ship Zhu Kezhen will spend the next few months trawling around 60,000 square kilometers (23,200 square miles) pinging the ocean floor with echosounding sonar.

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