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Old 6th Apr 2014, 04:53   #9261 (permalink)
 
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Angus Houston says first detection was a short detection 36 hours ago, the Chinese ship then came to the area to stay in the area. Yesterday afternoon was when the second detection was made, which was a longer detection than the first.

So all this about the Chinese "running their own race" is just media speculation...
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Old 6th Apr 2014, 04:54   #9262 (permalink)
 
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Quote:
Originally Posted by V-Jet View Post
Speaking well. Finally a non idiot speaking sense.

' rest assured every single possible lead will be fully explored and updates will be provided'
I don't know about that - he's deliberately not saying anything, and that sounds like they have put the Chinese "acoustic event" at the bottom of the list they have already programmed to search.

HMS Echo - is 14 hours away from 25s 101e and

Ocean Shield is investigation "another" acoustic event (that was only heard 1 hour ago), and is at least 24 hours away, and 27 hours before they could start searching, if they decide to abandon the "event" they are currently investigating.
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Old 6th Apr 2014, 04:55   #9263 (permalink)
 
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HMAS Ocean Shield has picked up a detection 90 mins ago...
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Old 6th Apr 2014, 04:56   #9264 (permalink)
 
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I find it interesting that it is only the Chinese supposedly finding objects and that one of their ships had got a ping. Could this be a ploy to keep the search from being scaled back by other country's.
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Old 6th Apr 2014, 04:59   #9265 (permalink)
 
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Quote:
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.
Indeed. Which I thought was a lot more professional than journo's discussing alien abductions etc.

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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Old 6th Apr 2014, 04:59   #9266 (permalink)
 
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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)
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Old 6th Apr 2014, 05:00   #9267 (permalink)
 
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Western ship just picked up a ping

Quote:
I find it interesting that it is only the Chinese supposedly finding objects and that one of their ships had got a ping.
Per the press conference, a western ship (Ocean Shield) picked up an acoustic signal about 90 minutes ago and is slowly turning around (with 6km of cable trailing) to try to sort it out. No more details.

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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Old 6th Apr 2014, 05:00   #9268 (permalink)
 
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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.
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Old 6th Apr 2014, 05:07   #9269 (permalink)
 
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Quote:
Originally Posted by Mesoman View Post
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.
You are assuming that the different boxes have to be in the same place..
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Old 6th Apr 2014, 05:07   #9270 (permalink)
 
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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.
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Old 6th Apr 2014, 05:09   #9271 (permalink)
 
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But he did confirm that the Chinese ship WAS and IS working in the defined search area!
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Old 6th Apr 2014, 05:17   #9272 (permalink)
 
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Widely separated ping detects, and probabilities

Quote:
You are assuming that the different boxes have to be in the same place..
It is pretty hard to come up with a likely scenario that separates the boxes by 300mi. Possible, but pretty unlikely.

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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Old 6th Apr 2014, 05:19   #9273 (permalink)
 
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Quote:
Originally Posted by Mesoman View Post
I believe these devices simply emit an unmodulated, short burst of 37.5khz energy.
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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Old 6th Apr 2014, 05:29   #9274 (permalink)
 
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Not a continuous tone

Quote:
Its a continuous tone, but it's getting weaker every day as the batteries run down
No, it's not a continuous tone. My only question is whether it has modulation. I have not read about that, so my bet is that it is not modulated.

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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Old 6th Apr 2014, 05:30   #9275 (permalink)
 
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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
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Old 6th Apr 2014, 05:32   #9276 (permalink)
 
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Quote:
According to ABC news 24 the discovery was made from 'rubber ducky' (their words) with a hydrophone!
Slang for an RIB.
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Old 6th Apr 2014, 05:33   #9277 (permalink)
 
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Not a continuous tone - Agree

http://rjeint.com/pdf/DK120.PDF
and the 8.5 Khz
http://www.radiantpowercorp.com/file...2501338125.pdf
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Old 6th Apr 2014, 05:42   #9278 (permalink)
 
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Various reports have the acoustic signals heard by the Chinese ship at 25S 101E. 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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Old 6th Apr 2014, 06:05   #9279 (permalink)
 
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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!

Last edited by rigbyrigz; 6th Apr 2014 at 06:08. Reason: punctuation
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Old 6th Apr 2014, 06:09   #9280 (permalink)
 
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Not just semantics

Quote:
semantics, 0.9 pulses per second, continuously.
This isn't just semantics.

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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