Malaysian Airlines MH370 contact lost
he's deliberately not saying anything, and that sounds like they have put the "acoustic event" at the bottom of the list they have already programmed to search.
I think it was a case of 'we have this stuff to confirm, it's been almost 24 hours we are doing the best we can - don't jump at shadows'
I hope I didn't miss the gist of anything significant, I was listening and typing on different screens and couldn't do both at the same time (ipad).
I've been stuck in hotel rooms not able to get news before which is frustrating. Nice to return the favour I have received from others in the past.....
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for those who can't pick up live stream...
Malaysia Airlines MH370: Tony Abbott urges caution after Chinese ship detects pulse in southern Indian Ocean
Prime Minister Tony Abbott says searchers are "hopeful but by no means certain" that a pulse signal detected by a Chinese ship in the Indian Ocean is related to missing Malaysia Airlines flight MH370.
Mr Abbott has urged caution following the most recent finding in a trail of disappointing leads to date.
"We need to be very careful about coming to hard and fast conclusions too soon," he said.
"This is the most difficult search in human history. We are searching for an aircraft which is at the bottom of a very deep ocean and it is a very, very wide search area."
Malaysia Airlines MH370: Tony Abbott urges caution after Chinese ship detects pulse in southern Indian Ocean - ABC News (Australian Broadcasting Corporation)
Prime Minister Tony Abbott says searchers are "hopeful but by no means certain" that a pulse signal detected by a Chinese ship in the Indian Ocean is related to missing Malaysia Airlines flight MH370.
Mr Abbott has urged caution following the most recent finding in a trail of disappointing leads to date.
"We need to be very careful about coming to hard and fast conclusions too soon," he said.
"This is the most difficult search in human history. We are searching for an aircraft which is at the bottom of a very deep ocean and it is a very, very wide search area."
Malaysia Airlines MH370: Tony Abbott urges caution after Chinese ship detects pulse in southern Indian Ocean - ABC News (Australian Broadcasting Corporation)
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Western ship just picked up a ping
I find it interesting that it is only the Chinese supposedly finding objects and that one of their ships had got a ping.
It is not in the same area (I think 300 mi apart).
These were just characterized as "fleeting acoustic events."
There is also aircraft sighted debris somewhere in the search area that ships are being dispatched to investigate.
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Not just Chinese, an Australian ship has also found a ping in another location farther north (they were a little vague on exactly where it is).
Assuming they rule out the Northern ping, they will meet with chinese ship at the southern ping location, which is also in the newly adjusted 'most likely' area.
Assuming they rule out the Northern ping, they will meet with chinese ship at the southern ping location, which is also in the newly adjusted 'most likely' area.
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These ping detections in different areas (two within 2km on 2 days by Chinese, one in another by the west), cannot both be MH370. I think thus shows that these ping detections are not very certain, so the second detect *lowers* the probability that either detect is correct.
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Another acoustic event reported in the last 90 minutes at another location being investigated by ADV Ocean Shield. The Chinese events were 24 hours apart within 2 km of each other, the new event is not in the same area.
New INMARSAT data indicate that the southern search area off OZ is more probable than the others on the south leg. The airspeed of MH 370 may have been greater than earlier calculated increasing the probability that the plane ditched near the signals detected by the Chinese vessel Haixun 01.
I agree, Angus Houston is the real deal as a leader giving the briefing.
New INMARSAT data indicate that the southern search area off OZ is more probable than the others on the south leg. The airspeed of MH 370 may have been greater than earlier calculated increasing the probability that the plane ditched near the signals detected by the Chinese vessel Haixun 01.
I agree, Angus Houston is the real deal as a leader giving the briefing.
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Widely separated ping detects, and probabilities
You are assuming that the different boxes have to be in the same place..
Angus Houston is pretty clear that these detects are iffy. However, he also said that these pings are the most promising leads so far. According to the CNN correspondent, the latest, refined satellite-based estimates target the same narrower area as where the pings were heard.
I believe these devices simply emit an unmodulated, short burst of 37.5khz energy. This is not a highly distinct signal, especially if it is very weak and thus corrupted by a lot of noise. Perhaps someone with more knowledge can comment on the nature of these "pings."
A comment... these ULB pings are unrelated to the satellite pings. The satellite pings are request/response transmission pairs. The ULB pings are just bleeps emitted periodically by the ULB.
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Its a continuous tone, but it's getting weaker every day as the batteries run down, and if a ship is underway it could well just pick the signal up for a few minutes as it passed by the edge of reception.
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Not a continuous tone
Its a continuous tone, but it's getting weaker every day as the batteries run down
You may be thinking of 121.5/243 MHz RF ELT's - a very different beast. They emit a continuous RF signal with frequency swept AM modulation that sounds like an alert siren. Newer ones emit less power than in the past, because the primary beacon is now a periodic digital burst on about 406 MHz, and the VHF signal is intended only for localization as opposed to primary detection.
Burst signals give better battery life. You get better detection with short loud (higher power) bursts than long quieter ones. However, more modern equipment, in theory, can do about the same with either one (by integrating the long quieter signal over time achieving the same SNR as the short louder one).
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pingers and news events
Back again after reading lots of threads on here re why where who it was and about how this person/nation is screwed up and how the Americans/Brits/ Oz ect ect can handle it better.
Come on guys get real. there are 239 lost souls on that aircraft as well as the fact that there are other 777 aircraft or aircraft of the same build standard out there flying about.
If some one finds a ping or signal that may or may not lead to finding this hull or what ever is left of it then thats good for the investigation good for the industry and not to mention some closure for the relatives. I dont care who finds what so long as some one does and if as I hope it turns out that it is in fact credible and the hull is located then the real investigation can start to swing into action and we can all get the answers that we need to know.
In answer to some threads on here about the Malays holding back info. Yes they have a right to with hold what ever they feel should not be released at that present time. The police when they investigate crimes do not allways release all the information on the incident under investigaion and should not be expected to lest they give away vital clues they dont really want others to know that they know. So to all those who are hammering the Malays and the others involved in this regarding release of information to just back off and let them get on with it. Let them concentrate on the task of finding the hull and not have to ansewer so many stupid questions and defending the line they are taking.
The time to hang and go after them if there is a need will be at the end when its all settled and the wash up takes place. Wait for the final report on this to be published and then and only then if there is a need to comment that will be the time to do so..
Oh CNN, I have stopped watching your coverage, what a load of cobblers some of your specialists spout and no doubt enflame the situation with the relatives. I cant watch and listen any more. Chanel news asia is a bit better
Come on guys get real. there are 239 lost souls on that aircraft as well as the fact that there are other 777 aircraft or aircraft of the same build standard out there flying about.
If some one finds a ping or signal that may or may not lead to finding this hull or what ever is left of it then thats good for the investigation good for the industry and not to mention some closure for the relatives. I dont care who finds what so long as some one does and if as I hope it turns out that it is in fact credible and the hull is located then the real investigation can start to swing into action and we can all get the answers that we need to know.
In answer to some threads on here about the Malays holding back info. Yes they have a right to with hold what ever they feel should not be released at that present time. The police when they investigate crimes do not allways release all the information on the incident under investigaion and should not be expected to lest they give away vital clues they dont really want others to know that they know. So to all those who are hammering the Malays and the others involved in this regarding release of information to just back off and let them get on with it. Let them concentrate on the task of finding the hull and not have to ansewer so many stupid questions and defending the line they are taking.
The time to hang and go after them if there is a need will be at the end when its all settled and the wash up takes place. Wait for the final report on this to be published and then and only then if there is a need to comment that will be the time to do so..
Oh CNN, I have stopped watching your coverage, what a load of cobblers some of your specialists spout and no doubt enflame the situation with the relatives. I cant watch and listen any more. Chanel news asia is a bit better
According to ABC news 24 the discovery was made from 'rubber ducky' (their words) with a hydrophone! 
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Not a continuous tone - Agree
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Various reports have the acoustic signals heard by the Chinese ship at 25°S 101°E. That's basically right on top of the 0:11 UTC 40° satellite ping arc calculated by Inmarsat, is it not?
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In the PC, A. Houston did his utmost to "smooth the waters" of the Chinese adherence to the overall plan, and give them much credit, but it does seem from awkward answers at times that there may have been some worrisome issues heretofore. His 2 hour meeting with the ambassador last night as well as his "realistic acceptance" that on-site press might sometimes jump the gun, all seem designed to improve the situation going forward.
Yes, the Chinese were "roughly in the general search area", in fact closer to the "just refined satellite re-look" that gives "more probability" to the southern boundary of the search area. Perhaps the Chinese experts independently tinkered with the satellite data that suggests this; or maybe their satellite or aircraft sightings were part of the equation for their focus.
It seems the Chinese ship, the HMS Echo, and the Ocean Shield all have different capabilities to verify and otherwise decipher acoustic events, with (per A. Houston and the Commodore) the Ocean Shield being the ablest. It is a shame therefore that it may be delayed 2 days before getting to the Chinese incident area, to do it's own separate acoustic verification, as battery life dwindles. I would think another "equally able" ship (USA or otherwise) would be an invaluable asset just about now!
Yes, the Chinese were "roughly in the general search area", in fact closer to the "just refined satellite re-look" that gives "more probability" to the southern boundary of the search area. Perhaps the Chinese experts independently tinkered with the satellite data that suggests this; or maybe their satellite or aircraft sightings were part of the equation for their focus.
It seems the Chinese ship, the HMS Echo, and the Ocean Shield all have different capabilities to verify and otherwise decipher acoustic events, with (per A. Houston and the Commodore) the Ocean Shield being the ablest. It is a shame therefore that it may be delayed 2 days before getting to the Chinese incident area, to do it's own separate acoustic verification, as battery life dwindles. I would think another "equally able" ship (USA or otherwise) would be an invaluable asset just about now!
Last edited by rigbyrigz; 6th Apr 2014 at 05:08. Reason: punctuation
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Not just semantics
semantics, 0.9 pulses per second, continuously.
When talking about signals, "continuous" has a specific meaning.
This signal is off over 99% of the time. That means the battery can last almost 100 times as long, or it can use over 100 times (20dB) the signal power than a continuous signal. It also means that, if it is heard regularly for short bursts, the probability that it's a ULB rather than an artifact is much higher than the detection of a continuous signal - because this gives a signature unlikely to be found in nature or from unrelated technology.
In signal processing - i.e. what you need to do detection - all of this is very important.
In terms of search strategy, I suppose it could be thought of as "frequent" in the sense that you are likely to hear the signal more than once during a detection.
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CNN is reporting...
"A British Royal Navy vessel is on its way to an area where a Chinese ship reported picking up electronic signals twice, once on Friday and again on Saturday, said Angus Houston, the head of the Australian agency coordinating search operations.
And the Australian naval ship Ocean Shield, which has highly sophisticated equipment, is pursuing "an acoustic noise" that it detected in a different area, Houston said at a news conference.
He said the detections were "an important and encouraging lead," but he cautioned that they be treated "carefully" as they haven't been verified as being related to Flight 370".
And the Australian naval ship Ocean Shield, which has highly sophisticated equipment, is pursuing "an acoustic noise" that it detected in a different area, Houston said at a news conference.
He said the detections were "an important and encouraging lead," but he cautioned that they be treated "carefully" as they haven't been verified as being related to Flight 370".
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Underwater Locator Beacon & Towed Pinger Locator
All the acoustic pings are 10 milli Sec long. At a once per second repetition rate. In good conditions the 190 gram! Dukane ULB can be detected by the Phoenix Model 25 Towed Pinger Locator within 12,000 Ft.
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abc is reporting...
"....Angus Houston said the British navy's HMS Echo, which is fitted with sophisticated sound locating equipment, is moving immediately to the area where the Haixun 01 detected the signals. The Australian navy's Ocean Shield, which is carrying high-tech sound detectors from the U.S. Navy, will also travel to the area".
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With respect to receiving the underwater pings.
If the pings are regular and for 10 ms every 1 second. Would it not be possible to take the received signal over that period and then sum/pile each 1 second of reception on top of each other 1 second of reception at that frequency in order to improve the signal to noise ratio?
I have done similar things in both amateur radio and also in astrophotography where you sum the received light from night photos to get a better pictures of faint objects. Essentially you improve the signal to noise ratio by doing so.
I hope that the aircraft and ships are recording their reception of the 37.5 khz frequency and time stamping it because later computer analysis using methods such as outlined above could pull out signals that are not audible to the human ear. The news that the Chinese were not recording what they were hearing doesn't sound good however. I hope teh othernatiosn searching are recording all their received static.
The No 1 guy who should be consulted re picking out weak signals like this is Professor Joe Taylor K1JT who is a noble laureate in physics. he has designed software that enables a weak signal of less than a watt to be heard and identified/decoded on the other side of the world.
If the pings are regular and for 10 ms every 1 second. Would it not be possible to take the received signal over that period and then sum/pile each 1 second of reception on top of each other 1 second of reception at that frequency in order to improve the signal to noise ratio?
I have done similar things in both amateur radio and also in astrophotography where you sum the received light from night photos to get a better pictures of faint objects. Essentially you improve the signal to noise ratio by doing so.
I hope that the aircraft and ships are recording their reception of the 37.5 khz frequency and time stamping it because later computer analysis using methods such as outlined above could pull out signals that are not audible to the human ear. The news that the Chinese were not recording what they were hearing doesn't sound good however. I hope teh othernatiosn searching are recording all their received static.
The No 1 guy who should be consulted re picking out weak signals like this is Professor Joe Taylor K1JT who is a noble laureate in physics. he has designed software that enables a weak signal of less than a watt to be heard and identified/decoded on the other side of the world.