Originally Posted by
awblain
Richard, Under similar assumptions does that rule out the Northern route? I assume that must require a weird combination of speed and track changes to remain consistent with the timings.
Neither the distance change away from the satellite between the hourly pings nor any potential Doppler information would by itself rule out a Northern location, any better than reasonable assumptions about the aircraft being spotted enroute ruled it out a week ago. It's also not really clear why today's news, if the better Inmarsat analysis is all there's been, merits the appearance of the Malaysian PM or the move of the victims' families to Perth.
Because INMARSAT have also reviewed the pings from other Malaysian 777s that flew northerly routes and their doppler signature was different to that received from MH370. As that rules out a northerly track it places the missing aircraft in the southern Indian Ocean, without a landing site anywhere near, and hence the need to tell the families that there is now no hope of survival.
[ edit to add this, from BBC - Engineers spent all weekend looking back at previous Malaysian Airlines Boeing 777 flights, going back several weeks.
They compared the satellite data from those flights with flight MH370 and were able to work out it went south.
This is cutting-edge modelling, never tried before. It uses the Doppler effect - which is what makes a police siren sound different from different points.
They had it reviewed by other scientists before handing it over.
As far as they can tell, the plane was flying at cruising height, above 30,000ft. They found no evidence of fluctuating heights being reported.
This is it now - they cannot pinpoint the position any further. They handed this data over on Sunday morning. ]