Feeds

Inmarsat: Doppler effect helped 'locate' MH370

Mind you, we still haven't found the wreckage

Eight steps to building an HP BladeSystem

As air and sea searches continue to try and identify and retrieve wreckage from Malaysia Airlines MH370's presumed crash site in the southern Indian Ocean, Inmarsat has briefed Reuters on how it estimated the path the flight took.

Since relatively early in the search for the flight, reference has been made to the seven “pings” Inmarsat satellites received from the aircraft after it stopped communicating with air traffic control.

Initially, those pings gave two possible tracks for MH370: one heading north-west, which gave rise to a huge number of conspiracy theories suggesting it had been hijacked and landed somewhere on that path; and one heading towards the Indian Ocean.

Inmarsat has now told Reuters it took a second look at the satellite pings, focussing on how much they deviated from the notional frequency of the transmitter, to try and decide which of the two paths the aircraft took.

If we ignore the Reuter's “19th century physics” angle, that's still an impressively accurate frequency resolution: taking the cruising velocity of the aircraft as around 250 m/second, its impact on a 1 GHz signal would be a change of around 0.08 per cent, even if MH370 had been flying directly at the satellite.

With Inmarsat at geostationary orbit, the Doppler effect on signals from the aircraft must truly be tiny. It's no surprise, then, that before releasing its results, Inmarsat passed its analysis to another company to check before making its announcement.

A discussion of the analysis has been published by the Malaysian Ministry of Transport, here.

The Sydney Morning Herald reports the area offering the best prospects to locate wreckage is probably in the vicinity of the Southeastern Indian Ridge, a zone of underwater volcanoes that hasn't been surveyed for more than 20 years. ®

Boost IT visibility and business value

More from The Register

next story
Motorist 'thought car had caught fire' as Adele track came on stereo
'FIRE' caption on dashboard prompts dunderheaded hard shoulder halt
Delaware pair nabbed for getting saucy atop Mexican eatery
Burrito meets soft taco in alleged rooftop romp outrage
Japanese artist cuffed for disseminating 3D ladyparts files
Printable genitalia fall foul of 'obscene material' laws
Carlos: Slim your working week to just three days of toil
'Midas World' vision suggests you retire later, watch more tellie and buy more stuff
Brit Rockall adventurer poised to quit islet
Occupation records broken, champagne corks popped
Accused! Yahoo! exec! SUES! her! accuser!, says! sex! harassment! never! happened!
Allegations were for 'financial gain', countersuit claims
Yahoo! Japan! launches! service! for! the! dead!
If you're reading this email, I am no longer alive
Plucky Rockall podule man back on (proper) dry land
Bold, barmy Brit adventurer Nick Hancock escapes North Atlantic islet
prev story

Whitepapers

Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.