Satcom equipment
 

Mr Peabody,
Can you tell us what causes the beam to be steered. Also, each time the beam is repositioned is there communication between the aircraft and the satellite?

Confirmation today by Aust PM that surface search will finish today.

Underwater search to continue over a "much larger area."

Makes sense. Little prospect of finding debris floating now (although something might wash up on a beach at some future date), and drift analysis now wound be extremely speculative.

Dumb question?
 

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.

Expanded Underwater Search.
 

According to PM Abbott and Angus Houston the entire 700km X 80km 'splash zone' will be searched using equipment and personnel from private contractors.
The search is estimated to cost ~$Au60mil, and will take at least eight months to complete.
Meanwhile the ships involved in the surface search will remain in the area for 'continuity' and Ocean Shield will continue using the Bluefin-21.

Yes, and without it the the SAR people would have had nowhere to start looking.

If one accepts the premise that someone rather than something caused this incident and that person hadn't considered that the Inmarsat method could be used then, using the logic of "when you've eliminated the impossible...", the motive must have been to make something disappear permanently.

Which begs the question; what could be so important as to go to all this trouble to attempt to permanently hide?

What was MH370 carrying?

Just watched the news conference on the new search area and outside contractors. On the positive side the university boffins should get some really good undersea bottom data.

It's interesting to see that many whales produce sound bursts in the region of 20kHz - but some species produce sound bursts up as high as 40kHz.
Seeing as the signals picked up by the Australian Navy were reported as being around 33kHz, I wonder if this might have been sound bursts from a whale?
Whale sound bursts are reported as travelling up to several hundred kms. The Cape Leeuwin hydrophones of the CTBTO are constantly being bombarded with whale signals.

Whale signals detected by International Monitoring System (IMS) facility: CTBTO Preparatory Commission

One has to ponder whether the major sounds produced by an aircraft ditching into the open ocean would be airborne or waterborne sound, as each has to be picked up by different methods and different instruments. It's interesting to note the CTBTO hydrophones pick up waves crashing, as permanent background noise.

The CTBTO has already stated the Cocos Island infrasound station did not, and could not, pick up any airborne sound from the region where MH370 is supposed to have been lost, due to extreme distance.

Acoustical Society of America - 166th Lay Language Papers

Or...maybe its like JORN and we Aussies dont turn things on at weekends :)
All jokes aside...given the reported sensitivity of these things, i am a little surprised that analysis of their data was neg...
Maybe means nothing.

micis - Station treaty code IS06 is an infrasound station on Cocos Island.

Station profiles - IS06 - Cocos Islands: CTBTO Preparatory Commission

The CTBTO has already searched their infrasound records for any signal peaks that might have come from MH370 on the morning of the 8th March and found nothing. This is because of the substantial distance from IS06 to the suspected crash site, and the high level of background noise created by wind, that is a feature of infrasound stations located on oceanic islands.

http://www.ctbto.org/fileadmin/user_...ines_MH370.pdf

One Track

You also have huge 30 - 40 foot waves crashing down at irregular intervals which must make some sort of noise. In addition, you have ships coming down off the top of these waves also making large sounds.

How would they differentiate between them ?

And wouldn't a ship make more noise than bits of aircraft falling into the water ?

Read it again
Whales are transmitting in Hz not kHz.

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.

threemiles - My apologies for my misreading of the frequencies. :uhoh:

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/

@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),

ELT Control Panel
 

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.

Inmarsat -
 

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.

Green-dot . . .
 

Maybe for the opposite reason why TPX & ACARS were deactivated, which is NOT speculation. :ooh:

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."

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.

Yes, that request to US came in package with asking Chinese to steer the weather so the drones could operate.