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Malaysian Airlines MH370 contact lost

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Malaysian Airlines MH370 contact lost

Old 28th Apr 2014, 07:58
  #10261 (permalink)  
 
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500N - The CTBTO obviously set up parameters for background or white noise for the likes of waves, and can relegate the noise to the area of no consequence.
I would expect a ship would have a different noise profile to an aircraft hitting the water, and that the major source of noise from ships would be engines operating.
Ships hulls crashing down into troughs would be only be an event that happens in extremely heavy seas, and as the CTBTO can pick up the direction where sound is coming from, this sound would normally only be heard from the direction of the Southern Ocean, and during sizeable storms.
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Old 28th Apr 2014, 08:00
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threemiles - My apologies for my misreading of the frequencies.

However, there's a good discussion in the link below that raises the possibility of a dying ULB producing a variance in frequency that could make its signal hard to distinguish from marine mammal noises.

http://mashable.com/2014/04/07/malay...-pings-whales/

Last edited by onetrack; 28th Apr 2014 at 08:29. Reason: addendum ..
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Old 28th Apr 2014, 09:21
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@onetrack.
This link you posted talks about the Cocos site as being to far away http://www.ctbto.org/fileadmin/user_...ines_MH370.pdf
But, the report was prepared well before the Southern Indian Ocean was the search site.
That being said, if it didnt pick up an explosion or splash impact from about 1000 k's, that means something/ (distance roughly from Cocos to Ocean Shield site),
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Old 28th Apr 2014, 09:22
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ELT Control Panel

Susier wrote:
Forgive me but what does the lettering at the top far left, near the red switch, say? That looks like ELT to me but my eyes can't make it out.


Might be BLT : )
Thanks Susier. I Did some research on the panel you refer to because the text on that panel was not readable from the ref. picture.

Indeed, it turns out to be the ELT control Panel. Not for a Honeywell ELT but for an ELTA ELT. As the document in the link below states:
"To be connected to any automatic ELT in A06 or ADT 406 range.":
http://www.elta.fr/uk_doc/RCP.pdf

So there is an ELT control panel installed in the MAS B772 fleet, this issue can be removed from the list. Question remains why the ELT was not activated. Without the facts the answer remains subject to speculation . . . . .519 pages of it in this thread and ongoing.
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Old 28th Apr 2014, 15:29
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Inmarsat -

lulu-the-dog

Have been following the thread with interest from the initial sad loss.
Would I be correct to say that the Inmarsat satellite technology that has lead the search to the Indian Ocean has not previously been used to locate a lost aircraft? Perhaps we would have been more surprised to find it?
It seems to me that while the mathematics etc are very plausible, at the end of the day the technology is unproven to say the least. Maybe its time to start over?
docrohan

While the application is new, the basics are very old....1842 to be exact
The doppler effect analysis is all they have to go on ATM....as far as we know
Although the ages old Doppler shift calculations have been newly applied to the geostationary Inmarsatt satellite the use of this technique is not new in modern day satellite Search And Rescue operations.

The COSAPAS/SARSAT polar orbiting (non-geostationary) satellites perform mathematical calculations based on the Doppler-induced frequency shift received by LEOSAR and MEOSAR satellites as they pass over a beacon transmitting at a fixed frequency. From the mathematical calculations, it is possible to determine both bearing and range with respect to the satellite. The range and bearing are measured from the rate of change of the received frequency, which varies both according to the path of the satellite in space and the rotation of the earth. This allows a computer algorithm to triangulate the position of the beacon with 2 or more passes. A faster change in the received frequency indicates that the beacon is closer to the satellite's ground track. When the beacon is moving toward or away from the satellite track due to the earth's rotation, that Doppler shift also can be used in the calculation.

Bear in mind that the difference here is that the COSPAS/SARSAT LEOSAR satellites are moving whilst the Inmarsat satellites are stationary relative to the Earth. But the principle remains the same and is well established. The calculations would be similar whether the target or the receiver is moving.

Inmarsat has said they have peer reviewed their data with other industry specialists; they may have consulted COSPAS/SARSAT Doppler shift experts.

Here are some background links:
Cospas-Sarsat System - International COSPAS-SARSAT
International Cospas-Sarsat Programme - Wikipedia, the free encyclopedia


My conclusion is that the location of a target by a satellite using Doppler shift has been proven many times before and although it is a new technique for Inmarsat birds, I think the maths can be trusted.
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Old 28th Apr 2014, 15:33
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Green-dot . . .

...Question remains why the ELT was not activated. Without the facts the answer remains subject to speculation . . . .
Maybe for the opposite reason why TPX & ACARS were deactivated, which is NOT speculation.
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Old 28th Apr 2014, 18:10
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Flight International

David Learmount is saying in his article in this week's Flight:

"Will MH370 ever be found? If it went into the southern Indian Ocean, probably not.

The facts are these: no floating wreckage has been found 6 weeks later. The accuracy of the satellite information on which the search area has been calculated is far from guaranteed, so the search team may not be looking in the right place."
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Old 28th Apr 2014, 18:17
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Maybe for the opposite reason why TPX & ACARS were deactivated, which is NOT speculation.
With accent on your 'Maybe' . . . . That the TPX & ACARS (and all radio comms) were deactivated may not be speculation but HOW and under which CONDITIONS they were deactivated has yet to be determined.
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Old 28th Apr 2014, 20:09
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Originally Posted by chumley
This may be a dumb question but has the US offered to or provided assistance in the sea surface search by the use of drones? If the haven't the question I would ask is why not? It would appear that they can readily pick out a terrorist target from altitude and conduct surveillance so why not utilise their range and stand off capability to conduct a detailed search of the Indian Ocean instead of putting PC3 Orions and other aircraft at risk.
Yes, that request to US came in package with asking Chinese to steer the weather so the drones could operate.
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Old 29th Apr 2014, 02:46
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Apparently a dangerous thought some minutes ago posted merely mentioning
United States Patent: 7142971 assigned to the Boeing Company.

Wouldn't dare to post a link, but would suggest a google of the U.S. patent # which reveals public disclosure of an interesting Boeing invention which describes........
"A method for automatically controlling a path of travel of a vehicle comprising: engaging an automatic control system of the vehicle"
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Old 29th Apr 2014, 03:12
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Anyone know about this?

A CNN 'expert' said that they had not searched the bottom near the area of the first and longest ping detect, because it was too deep for the Bluefin.

This certainly contradicts the impression I get from reading all of the JACC press releases and transcripts, but there is not precise refutation - I've seen no scaled map superimposing the high probability underwater search area and the four ping detects.

Does anyone have exact information to refute this, or might it be true?
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Old 29th Apr 2014, 04:23
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The 'expert' probably stopped reading after the first mission of the Bluefin; the one that was aborted as the ocean was a bit too deep. He might have forgotten that they modified the software to allow the Bluefin to go deeper, which would incur a risk that was deemed acceptable.
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Old 29th Apr 2014, 05:12
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7142971

@sks777flier

that's some patent.
surely nobody would install such a thing on a real airplane?
As a consumer I'd not knowingly ride in one so equipped.
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Old 29th Apr 2014, 06:01
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Boeing Patent

If I hadn"t seen the patent I would have thought we we were in the realms of sci fi. The idea that pilots would 'irrevocably lose control to an automated system' because 'for instance someone repeatedly pounded on the cockpit door" is truly frightening in its implications. But surely Boeing would not file such a patent unless they had some thoughts of implementing it?

Last edited by Andrewgr2; 29th Apr 2014 at 06:04. Reason: punctuation
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Old 29th Apr 2014, 06:58
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Forget about the patents. All big companies patent everything they can think of. 99% of it will never be implemented.
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Old 29th Apr 2014, 07:10
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SATCOM Equipment

Datayq1,


The beam steering unit is for the high gain antenna system. The beam steering unit receives digital beam steering signals from the satellite data unit. The satellite data unit provides known satellite positions and steering signals to create a beam point.


The antenna then uses the signals to make a narrow beam to the satellite.


The beam steering unit changes the beam steering signals into phase shift data which is sent to the high gain antenna. The high gain antenna then uses this data to aim the RF signal at the satellite.


When the SATCOM finds an active satellite it will lock onto it and attempt a log on. From lock-on the system will simply follow the satellite. If the beam is interrupted, then the system will reacquire the satellite and lock-on again, therefore another log on attempt.


We know that the satellite was indeed acquired by the hand shake communications every hour from Inmarsat.
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Old 29th Apr 2014, 08:21
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Boeing patent

If you look at that patent, it cites a long list of (very) similar patents attempting to cash in on, sorry, respond to, the post 9/11 hysteria. In all likelihood Boeing just obtained it as a defensive measure in case such a loony system were ever to be mandated and they found themselves being bent over a barrel for licensing fees. As someone else pointed out, just because a patent has been obtained doesn't mean it will ever be implemented. Nor has it.
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Old 29th Apr 2014, 08:21
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patents as ambit claims

I'm confident that the pilot lockout technology described in patent 7142971 was not a factor in the disappearance of MH370. Most patents are ambit claims, combining a range of innovations into a device that may or may not eventually prove viable. The point then is that any company that makes something that relies on any of these innovations has infringed on the patent. I doubt that Boeing has perfected a complete system as described, but if they have it would be doubly unlikely that it found is way into an aircraft that was flying before the patent was filed.
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Old 29th Apr 2014, 08:46
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Ping arc data released

Inmarsat ping-arc data released today via the Malaysian authorities
https://twitter.com/IvanCNN/status/4...043520/photo/1

Very first fit to the data is shown in figure 1 using a great circle at constant speed, fitting the course and start point. No surprise perhaps, the course heads straight for the original search area, so that _was_ defined by the ping data. It's an excellent fit, with the last point only a bit wobbly, an error of 0.6degrees on elevation. The other fitted points are have errors around 0.1degree in elevation.

However, as mentioned a _long_ time ago, the ping-arc/elevation data cannot distinguish courses with smooth changes of heading - they look like other great circle routes. Since the search area changed, then this must be what happened. More to come.

Figure 1: Best fit to the Inmarsat ping-arc data.

First Fit To The Inmarsat Ping-Arc Data Released 29th April 2014 Photo by RichardC10 | Photobucket

Last edited by RichardC10; 29th Apr 2014 at 09:47. Reason: Typo
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Old 29th Apr 2014, 10:36
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Are they going to release the Doppler rate if change data in relation to the Inmarsat?
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