Malaysian Airlines MH370 contact lost
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hamster3null wrote:
1. Best to distinguish between the words "false" and "mistaken." The former might imply that Inmarsat intentionally fabricated data or deliberately misinterpreted it. (And lawyers might call that libel.)
2. Inmarsat is not exposed to "huge liability" even if you assume some mistakes. A 777 with 239 souls was missing, and the search getting nowhere. Inmarsat apparently reported the information it had, along with various uncertainties, and then strove to refine and verify the data and the inferences from it.
It was the Australian government (and other parties) that decided how much to rely upon that data and interpretation and what resources to expend, presumably in consultation with others having some expertise.
In short, no obvious reason why Inmarsat would refrain from revising its conclusions if it thinks such revision warranted. Indeed, there already have been multiple revisions (that we know of) since the original announcement about northern and southern arcs.
By now they can't revise their conclusions, because Australians spent something like $43m based on their word and they'd be exposing themselves to a huge liability if their information proved false.
2. Inmarsat is not exposed to "huge liability" even if you assume some mistakes. A 777 with 239 souls was missing, and the search getting nowhere. Inmarsat apparently reported the information it had, along with various uncertainties, and then strove to refine and verify the data and the inferences from it.
It was the Australian government (and other parties) that decided how much to rely upon that data and interpretation and what resources to expend, presumably in consultation with others having some expertise.
In short, no obvious reason why Inmarsat would refrain from revising its conclusions if it thinks such revision warranted. Indeed, there already have been multiple revisions (that we know of) since the original announcement about northern and southern arcs.
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Marine animal acoustic tracking tag pings mistaken for ULBs?
Acoustic tags that transmit pings from 30 khz to 50 khz are used to track various species of large marine animals (i.e., sharks, whales, sea turtles, tuna, seals, etc). The ping interval is typically 1 second.
There's an interesting opinion piece in the Malaysian Insider by William Meacham, in he which claims the pings heard were not from the ULBs, but more likely from a marine acoustic tracking pinger.
The article is footnoted with his sources from reputable authorities. For example:
"Dr David Gallo, a senior scientist at Woods Hole and co-director of the successful search for the wreckage of AF447, wrote in an email to me: 'I don't know any underwater acoustic people that think the pings have anything to do with the plane.'”
Definitely worth a read.
There's an interesting opinion piece in the Malaysian Insider by William Meacham, in he which claims the pings heard were not from the ULBs, but more likely from a marine acoustic tracking pinger.
The article is footnoted with his sources from reputable authorities. For example:
"Dr David Gallo, a senior scientist at Woods Hole and co-director of the successful search for the wreckage of AF447, wrote in an email to me: 'I don't know any underwater acoustic people that think the pings have anything to do with the plane.'”
Definitely worth a read.
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rampstriker - That's an interesting opinion piece regarding the pings. In line with that opinion, I would consider by far the most concerning angle, would have to be the inability of the TPL-25 to pick up consistent, repeated pings, once the pings had been recorded over a 2 hr period.
If the emailed opinion of the Woods Hole senior scientist, Dr David Gallo is reportedly correct, in that he says, “I don't know any underwater acoustic people that think the pings have anything to do with the plane.” - then in line with the other concern, in that not a single scrap of wreckage has been found - it does give serious concern as to the final position of MH370 being where the JACC is convinced it is.
One has to consider the fact that after 8 weeks, if the aircraft did ditch in the Indian Ocean, then at least even one small piece of wreckage would have washed up on some Indian Ocean shore.
The longer times goes on without a shred of wreckage being found on some shore, seriously increases the doubt level.
Add in the vast Ocean area combed for over 6 weeks by some pretty hi-tech aircraft, and thousands of SAR eyes, both on the water and above it, and one is left with a distinctly uncomfortable feeling that the aircraft is not where the JACC thinks it is.
If the emailed opinion of the Woods Hole senior scientist, Dr David Gallo is reportedly correct, in that he says, “I don't know any underwater acoustic people that think the pings have anything to do with the plane.” - then in line with the other concern, in that not a single scrap of wreckage has been found - it does give serious concern as to the final position of MH370 being where the JACC is convinced it is.
One has to consider the fact that after 8 weeks, if the aircraft did ditch in the Indian Ocean, then at least even one small piece of wreckage would have washed up on some Indian Ocean shore.
The longer times goes on without a shred of wreckage being found on some shore, seriously increases the doubt level.
Add in the vast Ocean area combed for over 6 weeks by some pretty hi-tech aircraft, and thousands of SAR eyes, both on the water and above it, and one is left with a distinctly uncomfortable feeling that the aircraft is not where the JACC thinks it is.
Last edited by onetrack; 9th May 2014 at 03:40. Reason: correction as per Sheep Guts note ..
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Onetrack,
Just a minor correction to your post.
The Bluefin21 does not pick up 37.5 kHz acoustic pings its an Underwater Autonomous Vehicle with sonar mapping capability only. Unfortunately its operating limit 4500m depth maybe now of a concern, since nothing has been found.
The TPL-25 Towed Pinger Locator is what I think you are referring to.
That's an interesting opinion piece regarding the pings. In line with that opinion, I would consider by far the most concerning angle, would have to be the inability of the Bluefin 21 to pick up consistent, repeated pings, once the pings had been recorded over a 2 hr period.
Just a minor correction to your post.
The Bluefin21 does not pick up 37.5 kHz acoustic pings its an Underwater Autonomous Vehicle with sonar mapping capability only. Unfortunately its operating limit 4500m depth maybe now of a concern, since nothing has been found.
The TPL-25 Towed Pinger Locator is what I think you are referring to.
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Experts....
one is left with a distinctly uncomfortable feeling that the aircraft is not where the JACC thinks it is.
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Woods Hole Expert
The article is footnoted with his sources from reputable authorities. For example:
But... I'd like to see someone else, or Woods Hole itself, corroborate this. After all, the pings were picked up by the experts using the TPL, and their whole job is finding these pingers. Aussie acoustic experts reportedly (per Angus Houston) verified them.
Thus I find it unlikely (but not impossible) that the searchers are on the wrong track in this regard. More likely is that the article is wrong and the authorities are misquoted. I suspect we'll know one way or the other in a day or two.
Currently, the Woods Hole site, which has a FAQ on this search, doesn't mention ULB's at all.
I don't own this space under my name. I should have leased it while I still could
Acoustic tags that transmit pings from 30 khz to 50 khz are used to track various species of large marine animals (i.e., sharks, whales, sea turtles, tuna, seals, etc).
Had there been such a tag set to operate at that frequency I would have expected to someone to come up and say, 'Hey guys, you are tracking my great white . . . '
Raw Data
MH370 families urge govts to release raw satellite data - The Rakyat Post - The Rakyat Post
Reacting to the tripartite meeting, Voice370 said given the lack of tangible evidence of what happened to MH370, Putrajaya should “share and release the raw Inmarsat satellite engine ping data for 9MMRO (every ping from Friday, March 7 midnight until the final signal), “so that it can be subject to broader analysis by relevant experts”.
Voice370 said Inmarsat’s data only indicated a probable southern flight path but that it was not a definitive conclusion.
“The Inmarsat satellite data is the only lead we have and is key to identifying MH370’s flight path,” it said.
“In view of the lack of emergency locator transmitter (ELT) activation, zero detected debris, and the lack of convincing pings, we feel that it is necessary that the data be subjected to independent third party review,” the group said.
Reacting to the tripartite meeting, Voice370 said given the lack of tangible evidence of what happened to MH370, Putrajaya should “share and release the raw Inmarsat satellite engine ping data for 9MMRO (every ping from Friday, March 7 midnight until the final signal), “so that it can be subject to broader analysis by relevant experts”.
Voice370 said Inmarsat’s data only indicated a probable southern flight path but that it was not a definitive conclusion.
“The Inmarsat satellite data is the only lead we have and is key to identifying MH370’s flight path,” it said.
“In view of the lack of emergency locator transmitter (ELT) activation, zero detected debris, and the lack of convincing pings, we feel that it is necessary that the data be subjected to independent third party review,” the group said.
Winds/conditions are irrelevant for that. It would be important to get the timing right relative to the Satellite position and movement.
When replicating 1:1 it should become possible to identify deviations from the calculated/assumed course/speed combination, thereby validating the current search area.
Amplitudes and steepness of Doppler shift change should be identical.
If this cannot be replicated exactly 1:1 it may be time for a re-think.
Plus the steepness of the change of Doppler shift tells you something about the effective Speed vector of the aircraft relative to the satellite.
Steeper drop in Doppler means faster airspeed or more orthogonal course relative to the arc.
Since there is a mutual dependency of Speed, angles relative towards the arcs and timing of crossing of the different arcs, you could draw conclusions regarding where exactly to search from deviations or match of the values seen with MH370.
Edit: The more orthogonal the course relative to the arcs, the more even spaced will the Timings be between crossing the different arcs (if we assume a constant airspeed in the last stage of the flight). Thus there will be a more or less unique pattern for each combination of Speed and course, only limited by the accuracy of the data.
Last edited by henra; 9th May 2014 at 08:34.
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i somehow fail to understand all this ...
we remember the reports where the search teams received pings which
a) were on the final arc of handshakes
b) were recorded, anylysed and verified to be from an ULB.
c) started to fade out at the 30 day battery limit.
knowing the very limited range of the ULB pinger and using common sense to realise its to much concidence that a b and c together can be anything else than really mh 370 could lead to say " deepest respect you aussies - you really found the wreckage" ,just send the auv to confirm.
they did and... nothing ...
so in this mystery i see only two explanations
a) all the rumours are false, the pings were never from a blackbox ULB and they search in a more or less complete wrong position
b) the pings were from a blackbox ULB - and since no other aircraft crashed there last time for sure it can only be mh370 - but the bluefin is much more limited than released to media and simply failed to scan the wreckage even when it was in the right spot.
i do not see other explanations - normally when you hear the ULB you have found the aircraft.
we remember the reports where the search teams received pings which
a) were on the final arc of handshakes
b) were recorded, anylysed and verified to be from an ULB.
c) started to fade out at the 30 day battery limit.
knowing the very limited range of the ULB pinger and using common sense to realise its to much concidence that a b and c together can be anything else than really mh 370 could lead to say " deepest respect you aussies - you really found the wreckage" ,just send the auv to confirm.
they did and... nothing ...
so in this mystery i see only two explanations
a) all the rumours are false, the pings were never from a blackbox ULB and they search in a more or less complete wrong position
b) the pings were from a blackbox ULB - and since no other aircraft crashed there last time for sure it can only be mh370 - but the bluefin is much more limited than released to media and simply failed to scan the wreckage even when it was in the right spot.
i do not see other explanations - normally when you hear the ULB you have found the aircraft.
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A site about acoustic tags on marine animals says:
Ocean Tracks | Acoustic Tags
I presume that the SAR investigators were able to rule out the possibility of coded tags, for lack of that unique identifying number? (And why doesn't an aviation ULB broadcast the same unique information?)
That leaves continuous pingers as a possibility. Presumably, marine researchers have records of what they've tagged and where those tags were last 'heard'? And presumably the MH370 investigators will have co-ordinated with those science agencies?
There has to be a reason for the Australian's certainty about the source of the pings. Doesn't there?
The simplest electronic tags are acoustic tags. These can be surgically implanted inside the animal, or attached to a tether that has a delayed remote release mechanism. Two types of acoustic tags are used on marine animals: coded tags and continuous pingers. Coded tags regularly emit an ultrasonic signal that encodes a unique identifying number. This signal is detected and logged when the tagged animal is in close range (a few hundred metres) of a receiver stationed on the seabed or attached to a mooring. Continuous pingers are used for real-time tracking of marine animals from vessels fitted with a receiver for detecting the pinger. Some acoustic tags measure and transmit depth and temperature data when the animal is in range of the receiver. Coded acoustic tags are used to determine when animals visit particular sites, and can be used to examine long range movements between areas. Their batteries can last up to 10 years, allowing researchers to see how the behaviour of animals changes during different phases of life. Acoustic tags have been used since the late 1990s to study how white sharks occupy and move between coastal areas around Australia.
I presume that the SAR investigators were able to rule out the possibility of coded tags, for lack of that unique identifying number? (And why doesn't an aviation ULB broadcast the same unique information?)
That leaves continuous pingers as a possibility. Presumably, marine researchers have records of what they've tagged and where those tags were last 'heard'? And presumably the MH370 investigators will have co-ordinated with those science agencies?
There has to be a reason for the Australian's certainty about the source of the pings. Doesn't there?
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I presume that the SAR investigators were able to rule out the possibility of coded tags, for lack of that unique identifying number? (And why doesn't an aviation ULB broadcast the same unique information?)
As for uniquely coding aviation ULBs - there's not a lot of point since, unlike with tagged animals, in any given ocean in any given 30-day period it's hardly likely that there will be more than one pair of ULBs down there!
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As for uniquely coding aviation ULBs - there's not a lot of point since, unlike with tagged animals, in any given ocean in any given 30-day period it's hardly likely that there will be more than one pair of ULBs down there!
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But if an aviation ULB can't be distinguished from a similar device attached to an animal, you're depending on the aircraft crashing in an area where there aren't likely to be any tagged animals?
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Disagreeing Experts
Experts disagreeing with each other is nothing new, it's happening in court rooms around the world all day long.
What makes this extraordinary is that there are now two sets of experts disagreeing with each other, both over different sorts of pings, ULB pings and Satellite Pings.
Judging by the Atlantic article, it doesn't seem to me that the experts disagreeing (with the search authorities collective) on the issues of the satellite pings are Terry-Halfwit-with-a-calculator types. They would seem to have credibility, and I would hope they're now being listened to.
From the Malaysian Insider article, there would appear to be reasonable doubt cast by outside experts on the authenticity of the ULB pings as well.
I certainly wouldn't question the wisdom of the search strategy so far, (I've been involved in SAR for many years and it is always obvious afterwards), but given the lack of physical evidence I don't think it is unreasonable at this point to expect a re-think and a fresh analysis of the whole incident.
What makes this extraordinary is that there are now two sets of experts disagreeing with each other, both over different sorts of pings, ULB pings and Satellite Pings.
Judging by the Atlantic article, it doesn't seem to me that the experts disagreeing (with the search authorities collective) on the issues of the satellite pings are Terry-Halfwit-with-a-calculator types. They would seem to have credibility, and I would hope they're now being listened to.
From the Malaysian Insider article, there would appear to be reasonable doubt cast by outside experts on the authenticity of the ULB pings as well.
I certainly wouldn't question the wisdom of the search strategy so far, (I've been involved in SAR for many years and it is always obvious afterwards), but given the lack of physical evidence I don't think it is unreasonable at this point to expect a re-think and a fresh analysis of the whole incident.
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But they can be distinguished - aviation ULBs aren't coded, and transmit in bursts at 1 second intervals, not continuously.
Simple 'pingers' transmit regularly and continuously,
whilst transponders transmit on receipt of an external
signal.
whilst transponders transmit on receipt of an external
signal.
That suggests to me that there's a pulsing behaviour involved? I don't know whether that means microseconds or something in the order of minutes or hours. Is it implausible that a marine tag could be set to pulse at 1 second intervals? Or is this disallowed, on account of confusion with aviation ULBs? The transmission frequency detected was consistent with what marine scientists use to track animals in deep ocean, because the lower frequency travels further.
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"They did seem very sure that they had located a ULB though, in which case, your original point would still stand"
correct. lets forget all handshakes and inmarsat - when you receive in the middle of the indian ocean where no other aircraft crashed short range stationary pings from a device that is confirmed to be a blackbox ULB which start to fade away just 30 days after mh 370 vanished - what else can it be than a malaysian boeing 777 directly unter your feet ?
this pings either never existed or were from another source OR bluefin is not able to fully scan the bottom because otherwise MH370 must have been found .
correct. lets forget all handshakes and inmarsat - when you receive in the middle of the indian ocean where no other aircraft crashed short range stationary pings from a device that is confirmed to be a blackbox ULB which start to fade away just 30 days after mh 370 vanished - what else can it be than a malaysian boeing 777 directly unter your feet ?
this pings either never existed or were from another source OR bluefin is not able to fully scan the bottom because otherwise MH370 must have been found .
I can't find information on what 'continuous' means in terms of marine tag pinging. One site states:
"We developed the RATS to track the model V22P acoustic transmitter [...] which is specified to transmit a 36-kHz “ping” at 165 dB once every 700–1100 ms. The pulse duration of the ping is 10 ms"
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If I have understood the whale/shark tracking posts I have one question.
Why on earth (or this case in the sea) are they allowed to use a frequency 5khz either side of 37.5Khz - madness
Isn't there a control authority like radio frequencies.
Why on earth (or this case in the sea) are they allowed to use a frequency 5khz either side of 37.5Khz - madness
Isn't there a control authority like radio frequencies.
Last edited by oldoberon; 9th May 2014 at 11:55. Reason: add last question
This sounds worryingly close.
That might be: "back to square 1" I guess.
If true this leaves one speechless.