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Posted: Tue, 25 Mar 2014 12:03 am
by zzm9980
If Malaysia hasn't had their foot in their mouth so many times in the past few weeks I'd be less skeptical.
Posted: Tue, 25 Mar 2014 12:21 am
by PNGMK
zzm9980 wrote:So Malaysian PM has announced the flight was lost. As of right now I haven't seen any evidence that they know it was there. The news stories are just referencing the fact they haven't found it, satellite photos of debris, and an "analysis" which says it had to have flown towards the southern Indian ocean.
Inmarsat used doppler analysis of the frequency shift in the inmarsat transmitter pings.... to prove the pings were moving southward apparently. Pretty intensive maths and physics.
In very simple terms the frequency shift proved that the pings went underneath and then past the satellite I believe - which is only possible on a southerly track.
Sort of like a car blowing it's horn driving towards you...and then past you.
high pitch reducing in pitch to normal pitch then to an even lower pitch.
The data appears to have been vetted by the UK Accident investigation. I'd say it's solid and based on physics which is a lot better than most of the analysis in this investigation so far.
Posted: Tue, 25 Mar 2014 12:47 am
by zzm9980
PNGMK wrote:zzm9980 wrote:So Malaysian PM has announced the flight was lost. As of right now I haven't seen any evidence that they know it was there. The news stories are just referencing the fact they haven't found it, satellite photos of debris, and an "analysis" which says it had to have flown towards the southern Indian ocean.
Inmarsat used doppler analysis of the frequency shift in the inmarsat transmitter pings.... to prove the pings were moving southward apparently. Pretty intensive maths and physics.
In very simple terms the frequency shift proved that the pings went underneath and then past the satellite I believe - which is only possible on a southerly track.
Sort of like a car blowing it's horn driving towards you...and then past you.
high pitch reducing in pitch to normal pitch then to an even lower pitch.
The data appears to have been vetted by the UK Accident investigation. I'd say it's solid and based on physics which is a lot better than most of the analysis in this investigation so far.
Pretty solid then, if that's the case.
Posted: Tue, 25 Mar 2014 6:49 am
by sundaymorningstaple
sundaymorningstaple wrote:
Add to that, the pings picked up by the US communication satellites (of which were probably military in nature so we don't really know the full capabilities of which). I wonder if those satellites have some additional technology that allows them to also tell where (not what) they are coming from (I don't know if that is even feasible - as they are not sound waves like sonar)
Looks like I was thinking in the right direction even if I didn't know if it was feasible or not. Sounds like it anyway. Sure hope they can at least find some identifiable debris from the plane for closure at any rate.
Posted: Tue, 25 Mar 2014 8:11 am
by Strong Eagle
sundaymorningstaple wrote:sundaymorningstaple wrote:
Add to that, the pings picked up by the US communication satellites (of which were probably military in nature so we don't really know the full capabilities of which). I wonder if those satellites have some additional technology that allows them to also tell where (not what) they are coming from (I don't know if that is even feasible - as they are not sound waves like sonar)
Looks like I was thinking in the right direction even if I didn't know if it was feasible or not. Sounds like it anyway. Sure hope they can at least find some identifiable debris from the plane for closure at any rate.
I think it is down in that area and that positive id will soon be made. Now the big question is how deep is the water there? The flight data recorder pings can be picked up to about 20,000 feet in water, the ocean in this part dips to 23,000 ft or more.
Posted: Tue, 25 Mar 2014 8:42 am
by sundaymorningstaple
Too true. However, with a 3 knot current, the actual ditching site could be 1500~1800 km north if in fact they find any confirmation debris. I wonder how much +/- their pings calculation would be. They could probably be rather close on longitude based on trend/projections based on previous pings. If the directional heading had been reasonably stable and the time between pings being consistent then maybe a close approximation of speed factored, but latitude might be a problem. I wonder how close their current calculations would put them in relation to the recent debris field (as yet unverified by anything at all other than satellite imagery). And if the general debris field would possibly tie in based on the prevailing current/drift/time.
Posted: Tue, 25 Mar 2014 9:04 am
by rajagainstthemachine
I hope Malaysian govt really mean what they are saying.. I am rather sad to hear the plane ended up crashing, I was hoping for a miraculous ending to this long drawn saga but it seems like the people who have lost loved ones have suffered the most.
Posted: Tue, 25 Mar 2014 10:35 am
by rdueej
PNGMK wrote:
Inmarsat used doppler analysis of the frequency shift in the inmarsat transmitter pings.... to prove the pings were moving southward apparently. Pretty intensive maths and physics.
That would have been quite an impressive feat in analysis to make sure the frequency shifts were only due to the velocity doppler effect. These doppler shifts would have to be measured with an accuracy of better than 1 in a million and I can think of a number of other factors which could have also caused similar frequency shifts in the ping signals.
Sadly though, I think this only confirms the southern trajectory and cannot provide a location estimate for the final crash site. Maybe now, we can focus satellite imaging on this route for a better chance of finding debris.
Posted: Tue, 25 Mar 2014 11:20 am
by PNGMK
rdueej wrote:PNGMK wrote:
Inmarsat used doppler analysis of the frequency shift in the inmarsat transmitter pings.... to prove the pings were moving southward apparently. Pretty intensive maths and physics.
That would have been quite an impressive feat in analysis to make sure the frequency shifts were only due to the velocity doppler effect. These doppler shifts would have to be measured with an accuracy of better than 1 in a million and I can think of a number of other factors which could have also caused similar frequency shifts in the ping signals.
Sadly though, I think this only confirms the southern trajectory and cannot provide a location estimate for the final crash site. Maybe now, we can focus satellite imaging on this route for a better chance of finding debris.
I agree... very narrow shifts for sure. I assume Inmarsat themselves are able to access diagnostic or engineering data (i.e. RF frequencies) right off their satellite borne computer that the public would not normally need to know about or access.
Posted: Tue, 25 Mar 2014 6:14 pm
by rajagainstthemachine
apparently this is what it looks there ( you'll need your facebook accounts to view this though )
https://www.facebook.com/photo.php?v=50 ... =2&theater
Posted: Tue, 25 Mar 2014 6:18 pm
by rajagainstthemachine
and this is another really well written detailed article that mentions why all this took this long
http://www.telegraph.co.uk/news/worldne ... elays.html
Posted: Tue, 25 Mar 2014 7:00 pm
by PNGMK
Malaysia just looks (quite correctly) absolutely bloody incompetent. Days and days and days of critcal time wasted by them and all because of their stupid internal sensitivities and politics and complete lack of a meritocracy.
Posted: Tue, 25 Mar 2014 11:37 pm
by zzm9980
PNGMK wrote:
Malaysia just looks (quite correctly) absolutely bloody incompetent. Days and days and days of critcal time wasted by them and all because of their stupid internal sensitivities and politics and complete lack of a meritocracy.
Yeah I tend to agree.
Malaysia’s Prime Minister, Najib Razak, is reported to have told his investigators that all raw data had to be corroborated with other agencies before it was released to the public, to avoid the white noise of information and misinformation.
The Malaysian government has also suggested that it took a week to process all of the data it was receiving from multiple international sources and to eliminate red herrings.
According to the New York Times, US investigators tried telling the Malaysians they were looking in the wrong place a week after the aircraft disappeared, but their warnings were not heeded for several days.
France was said to have offered help on March 9 but was ignored for a week before the Malaysians finally agreed to meet experts who took part in the two-year search for the flight data recorders of the Air France jet that crashed into the sea north of Brazil in 2009.
Malaysian officials have also been accused of failing to share all the information from their own systems because they did want to admit weaknesses in their radar and satellite operations.
And while international experts would normally be told within 24 hours about ACARS data the Malaysians withheld it for several days. It was this information that suggested the Boeing 777 was deliberately turned to the west, away from its planned route to Beijing.
Posted: Wed, 26 Mar 2014 2:58 am
by earthfriendly
Inmarsat said for a relatively low cost its satellites could keep tabs on flights and provide data exchanged between the air and the ground to help organise routes to save time and fuel.
Its systems, which are widely used in shipping, have been embedded into surveillance and communications technologies that allow air traffic controllers to build up a picture of where aircraft are, and to better manage routes.
"If you have that (...) capability you get a preferred routing at the right altitude that makes your aircraft more fuel efficient, but if you don't have it you have to fly lower and get less priority in air-traffic control," said David Coiley, Inmarsat's vice-president for aeronautics.
The system is used in planes in the North Atlantic, Coiley told Reuters earlier this month, but it is not commonly used in all parts of the world.
Sinnatt said on Monday that such a facility would cost about $10 per flight. "It is something we have been pushing the industry to do because it significantly adds to safety," he said. Other satellite providers are also developing tracking systems.
Posted: Wed, 26 Mar 2014 9:50 am
by Max Headroom
As I understand it, both black boxes are overwritten every 30 minutes, so even if they did find them, the CVR would have nothing but 30 minutes of white noise and the FDR would show all parameters pretty much flat-lining eh.
And that's if they find them.
I think, now more than ever, a case can be made for uploading all black box data real-time, rather than keeping it in a metal box that you then have to go and find, bring up and parse; well, the bits that haven't been crushed, burned or water-logged.
I'm sure uploading is expensive, but so is endless needle-in-a-hay-stack sniffing around for a few metal boxes in a god-forsaken and ever-stormy ocean.