Malaysian Airlines MH370 contact lost
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FWIW, here is a little more detail on what the RAAF saw as reported be the pilot (per Xinhua):
RAAF says mutiple objects "verified", mission deemed "successful" - Xinhua | English.news.cn
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Lonewolf 50
According to latest on our side of the pond is the Malaysian PM`s announcement, compassionate and commiserating in nature rather than hard facts. The RAAF P3 crew have reported floating objects which appear to be a crate and belts. So nothing concrete as yet.
Good chance by early tomorrow the reported debris may be recovered by vessels in the area and promptly identified.
According to latest on our side of the pond is the Malaysian PM`s announcement, compassionate and commiserating in nature rather than hard facts. The RAAF P3 crew have reported floating objects which appear to be a crate and belts. So nothing concrete as yet.
Good chance by early tomorrow the reported debris may be recovered by vessels in the area and promptly identified.
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Already posted that they said they went back through weeks of other Malaysian 777 flights they had data for and examined the signal for those going northbound compared to the southbound ones and saw a Doppler shift (I guess?). So they're making a comparison not looking at MH370 alone.
similarly no talk of "jitters" I read in another thread.
similarly no talk of "jitters" I read in another thread.
If the same aircraft were to turn either X degrees left or X degrees right, radial speed (the component directed towards the satellite) would decrease, transverse speed would increase, and Doppler shift would decrease. But, since the system has mirror symmetry, the satellite has no way of knowing whether the aircraft turned left or right.
Like I said, we have a highly symmetric configuration (one satellite) and nothing evident to break the symmetry.
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hamster3null
Different surfaces north and south: land and ocean?
The talk about Doppler effect looks like techno-gibberish ... We have a radially symmetric configuration.
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I thought Chris McLaughlin of INMARSAT certainly had a dig at MAS this evening for being one of the airlines who choose not to follow the AF447 BEA recommendation 4.2.4 relating to transmission of flight data and who are now suffering the consequences of such inaction.
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This latest announcement makes zero sense to me physically. The talk about Doppler effect looks like techno-gibberish that makes me wonder what exactly they are hiding and why.
Supposing the orbit of the satellite were ever so slightly inclined to the equator. Then the satellite would appear to nutate North and South of the equator as viewed from earth and would create slight doppler effects at certain times of the day for stations essentially North and South of the satellite. Gotta be something like that.
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I have just listened to the BBC interview of a person from INMARSAT. If I understood correctly
1) they did create and provide a model of the likely "disappearance" zone about a week ago i.e. over a week after the event, based on analysis of pings and modelling of typical MH flights. Congratulations for the initiative to what is in principle a data-transmission organisation.
2) as search organisations did then go to the area, it is also logical that the Malaysians would want to also remain focussed on other scenarios until they had been rendered impossible. Had they not done so and had the Inmarsat model have subsequently been proved wrong would have been unfortunate.
If I add to that
3) as far as I have been able to ascertain, there is no firm evidence of what happened inside the plane after the last voice exchange
4) likewise there is little evidence of where it actually then flew and even less on how it got onto the track it seems to have followed, or for that matter any other possible tracks
I find the statement emanating from the Beijing family group very unfortunate and possibly due to a lack of counselling and understanding of the bigger picture. It is imperative that the industry works to communicate on why it takes time and thus avoid such happenings. That said, I have to admit that the comment of the Inmarsat responsible that, by obligation, ships are tracked every 6 hours and that a similar tracking could be instituted for aircraft blew me over, not by its simplicity, but by the fact that say ICAO has not mandated it. I hope they will see the value. We don't need another one like this.
1) they did create and provide a model of the likely "disappearance" zone about a week ago i.e. over a week after the event, based on analysis of pings and modelling of typical MH flights. Congratulations for the initiative to what is in principle a data-transmission organisation.
2) as search organisations did then go to the area, it is also logical that the Malaysians would want to also remain focussed on other scenarios until they had been rendered impossible. Had they not done so and had the Inmarsat model have subsequently been proved wrong would have been unfortunate.
If I add to that
3) as far as I have been able to ascertain, there is no firm evidence of what happened inside the plane after the last voice exchange
4) likewise there is little evidence of where it actually then flew and even less on how it got onto the track it seems to have followed, or for that matter any other possible tracks
I find the statement emanating from the Beijing family group very unfortunate and possibly due to a lack of counselling and understanding of the bigger picture. It is imperative that the industry works to communicate on why it takes time and thus avoid such happenings. That said, I have to admit that the comment of the Inmarsat responsible that, by obligation, ships are tracked every 6 hours and that a similar tracking could be instituted for aircraft blew me over, not by its simplicity, but by the fact that say ICAO has not mandated it. I hope they will see the value. We don't need another one like this.
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Perhaps there's an air temperature or humidity difference between the N & S arcs that would make differentiation possible? Land & sea and all that? I appreciate the altitude involved here.
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Satellite sees a Doppler shift when the aircraft is on a trajectory that brings it closer or further away from it. E.g., if the satellite is 45 degrees above the horizon from the point of view of the aircraft and the aircraft flies at 490 knots and steady altitude directly towards the satellite, and communications between the satellite and the aircraft occur at the frequency of 1.6 GHz, Doppler shift is 1.6e9*cos(45)*(490*1.852/3600)/299792=1903 Hz.
If the same aircraft were to turn either X degrees left or X degrees right, radial speed (the component directed towards the satellite) would decrease, transverse speed would increase, and Doppler shift would decrease. But, since the system has mirror symmetry, the satellite has no way of knowing whether the aircraft turned left or right.
Like I said, we have a highly symmetric configuration (one satellite) and nothing evident to break the symmetry.
If the same aircraft were to turn either X degrees left or X degrees right, radial speed (the component directed towards the satellite) would decrease, transverse speed would increase, and Doppler shift would decrease. But, since the system has mirror symmetry, the satellite has no way of knowing whether the aircraft turned left or right.
Like I said, we have a highly symmetric configuration (one satellite) and nothing evident to break the symmetry.
Inmarsat.
I was one of those who questioned the Inmarsat ping results. The constant 40deg angle running near KL seemed questionable.
Now that the techniques have been validated against multiple aircraft, my hypothesis (terminal tracked not aboard aircraft) is clearly disproved.
Full marks to those who crunched the data. Your work has helped bring closure to this tragic matter.
Now that the techniques have been validated against multiple aircraft, my hypothesis (terminal tracked not aboard aircraft) is clearly disproved.
Full marks to those who crunched the data. Your work has helped bring closure to this tragic matter.
After what has gone on in the last weeks I think that the RAAF would not say they had wreckage identified until they had it in hand and positively identified - even if it was a large chunk.
Just imagine the reaction if they this based only on a sighting and then were proven to be mistaken or couldn't recover it.
Just imagine the reaction if they this based only on a sighting and then were proven to be mistaken or couldn't recover it.
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To those questioning the Doppler shift analysis, and trying to rationalize how you could determine a north vs south heading, it's pretty simple. You are analyzing this as if the pings started on the equator, which we know they didn't. If part of the readings indicated the plane was getting closer before it was going away from the satellite, then it was heading south west. If all of the readings indicated the plane was getting father away, then it would be going north.
The fact that the plane didn't start on the equator is what breaks symmetry.
The fact that the plane didn't start on the equator is what breaks symmetry.
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TelCoAg
Exactly the case. Also the satellite moves slightly around an average orbital position which also contributes additive and subtractive doppler effects which break the directional symmetry if sensitive enough measurements can be made.
Exactly the case. Also the satellite moves slightly around an average orbital position which also contributes additive and subtractive doppler effects which break the directional symmetry if sensitive enough measurements can be made.
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INMARSAT 3-F1 Eccentricity
The INMARSAT 3-F1 is in a geostationary orbit above the earth at a nominal 35786km distance. At that nominal height its orbital speed enables it to remain stationary over the Equator and at 64.5°E. However, as the satellite is geosynchronous with a small offset to allow it to remain geostationary, causes its position both in distance above the earth and its nominal position, to change over a period of 1 siderial day (23.934 hours). This positional change is a small ellipse with a 1.6580° inclination that extends 1.59° north and south of the Equator in a very skinny figure of 8 shape.
The fact the eccentricity is predominately N and S has presented the possibility of determining the values of small doppler shifts in a signal being received from an aircraft that is either traveling N or S below it.
The above was extracted from http://www.n2yo.com/?s=23839 as the satellite had just started moving south in its eccentric ellipse.
The satellites eccentric speed (in relation to its Earth position) as it passes over the Equator every 11.97 hours is approximately 90m/s. This provides no Doppler shift effect to an observer directly below it, but the Doppler shift will become more evident the further N or S the earth observer is located.
The fact the eccentricity is predominately N and S has presented the possibility of determining the values of small doppler shifts in a signal being received from an aircraft that is either traveling N or S below it.
The above was extracted from http://www.n2yo.com/?s=23839 as the satellite had just started moving south in its eccentric ellipse.
The satellites eccentric speed (in relation to its Earth position) as it passes over the Equator every 11.97 hours is approximately 90m/s. This provides no Doppler shift effect to an observer directly below it, but the Doppler shift will become more evident the further N or S the earth observer is located.
Last edited by mm43; 25th Mar 2014 at 04:46. Reason: re phrasing image description
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Wrong pax and crew count
Originally Posted by nippysweetie
.hurt the families of the 154 passengers...
The official count is 129 passengers and crew!
If you cannot get your facts right please do no post.
Correction - 239, not 139. pointed out by Lonewolf 50. Thank you.
Every one of the 239 passengers had family and everyone of those families are hurt, not just the Chinese. Let's not bring a racial tone into this please.
Last edited by brika; 24th Mar 2014 at 20:50. Reason: correction
The 154 figure is how many people on that aircraft were from China.
"This shameless behaviour not only fooled and hurt the families of the 154 passengers but also misguided and delayed rescue actions, wasting a large quantity of human resources and materials and lost valuable time for the rescue effort.
"If the 154 passengers did lose their lives, Malaysia Airlines, the Malaysian government and military are the real executioners who killed them. We the families of those on board submit our strongest protest against them. "We will take every possible means to pursue the unforgivable crimes and responsibility of all three."
"If the 154 passengers did lose their lives, Malaysia Airlines, the Malaysian government and military are the real executioners who killed them. We the families of those on board submit our strongest protest against them. "We will take every possible means to pursue the unforgivable crimes and responsibility of all three."
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154 Chinese, perhaps? Which adds a certain dimension to the whole event.
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fuel exhaustion or not
Originally Posted by GobonaStick
Quote:No proof of fuel exhaustion.
However, point of fuel exhaustion calculated by estimated fuel load has been calculated....search areas appear to coincide as well.
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The fact the eccentricity is predominately N and S has presented the possibility of determining the values of small doppler shifts in a signal being received from an aircraft that is either traveling N or S below it.
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MPN11
That remark is unreasonable, these are deeply traumatised people who have just had their worst fears confirmed beyond any doubt and are trying to make some sense of it all.
Hamster3nul
Do not be so insulting about the AAIB, the best aircraft accident investigation service anywhere. The AAIB does not publish rubbish or write its conclusions to satisfy somebody's whims, it reports facts and you can be absolutely certain that, to quote G0ULI
and if they came to the conclusion which they published then that IS the conclusion. If you know better than the AAIB the you should let them know. However, I'm not that sure they would believe you after all, you didn't find the aircraft's track and position. The AAIB might just have a quiet giggle.
"Someone doth protest too much, methinks"
Hamster3nul
The talk about Doppler effect looks like techno-gibberish that makes me wonder what exactly they are hiding and why.
I know that the INMARSAT and AAIB boffins have the technical and mathematical skills to carry out the signal analysis to determine the details published.
Last edited by DX Wombat; 24th Mar 2014 at 21:10.
