Malaysian Airlines Flight MH-370 goes missing

Lalmohan · Post by **Lalmohan** » 27 Mar 2014 18:29

i dont think the plane got anywhere near india

UlanBatori · Post by **UlanBatori** » 27 Mar 2014 18:41

radars that weren't working.

This brings to mind a story.
The journalist was visiting an air force base near the India/China/Myanmar border. When he arrived there was only the custodian (person who sweeps the floor and keeps the pakistans clean), so he got to chatting with him.

I used to be an ace fighter pilot during WW2. The Japanese invasion was coming steadily closer, so we were on Red Alert. The Japanese did not let us sleep. Every night, about once every 30 minutes, the Air Raid Siren would go off, as a Japanese plane crossed the periphery of our radar coverage briefly. We would rush to our airplanes, turn on the instruments, turn on the engines, warm them up, monitor all gauges and wait for the order to take off. Then the Control Tower would order us to stand down, so we shut down everything, went back to bed - only to have to repeat this a short time later.

We were stressed out from lack of sleep, and fatigue.

So I hit upon an idea. We caught a monkey, and trained him with bananas and nuts. He became quite tame. We trained him secretly. He learned to leap inside a cockpit, turn on the instruments, turn on the engine, then, when the order came with the words "All Clear, Stand Down!" he would shut down the engine, shut down the instruments, and return.

I had the highest ratings for being the pilot with the fastest scramble time, getting everything turned on and off. And I got my sleep. People admired my ability to look so sharp and fit when they were all feeling half-dead.
*********************************************
One night the Japanese came...
**********************************************

So that's why I was reduced in rank and there is no hope of advancing beyond this assignment.

What happened to the monkey?

Oh! He retired as the Air Chief Marshall of the Pakistan Air Fauj!

A_Gupta · Post by **A_Gupta** » 27 Mar 2014 18:47

Breaking the INMARSAT symmetry:

It has been puzzling me - for each southern path that fits with the INMARSAT distance (angle over the horizon of the satellite from the plane) and Doppler information, there is a corresponding path that goes north. Basically, do a reflection across the geometrical plane that passes through the position of the satellite, the center of the earth, and the last mil. radar position of the aeroplane over the ~~Gulf of Thailand.~~ Strait of Malacca.{A}

Only a little while ago it hit me that while the above is certainly true, a southern path of constant compass heading will not reflect into a northern path of constant compass heading.

The INMARSAT people must be operating on the assumption that the plane was on autopilot for the last 6-7 hours of its flight. Then, if the autopilot preserves a compass heading, the northern path and southern path are not symmetric, because the plane's path does not begin on the equator.

CT - it is a puzzle if the pilot wanted to go to the southern seas in the first place, why all the tamasha of crossing from the Gulf of Thailand to the Strait of Malacca. How diabolical would it be if one wanted to reach a northern destination the route to which, when reflected as in {A} above, translates into a southern route of constant compass heading; and all that first part of the diversion of the flight was to get the plane into the right position to do that.

CRamS · Post by **CRamS** » 27 Mar 2014 19:14

Guys, question. Can there be any real time tracking. In other words, Aussies and their big brother US sitting in some control room somewhere get real-time images of these satellites, and then pass on the GPS coordinates to the pilots en route to the search area. And they keep updating them as the planes approach the general search area so the pilots can make slight changes to their flight path. After all, the flights from Perth take 4 hours or so to get to the general search area, and so there is enough time for tracking the images and updating the pilots. I assume they are already doing something like this, but the pilots fly so high that they simply cannot spot anything visually? Even with the most sophisticated magnifying glasses? Also, the planes should be equipped with cameras to take higher resolution pictures of the search area? Finally, its been what over a week or so that these images have been spotted and are being tracked, so by this time ships also must be in the area and are also being fed the latest GPS coordinates? I mean how is it possible that the satellites are seeing all these objects, but the planes and ships see nothing? What am I missing here?

ramana · Post by **ramana** » 27 Mar 2014 19:21

The sat images are a waste as they pick up flotsam and none of the Jetsam. The planes go to the sites and find junk.
Add to the woes there are competing agendas of the search teams.

shiv · Post by **shiv** » 27 Mar 2014 19:30

CRamS wrote:Guys, question. Can there be any real time tracking. In other words, Aussies and their big brother US sitting in some control room somewhere get real-time images of these satellites, and then pass on the GPS coordinates to the pilots en route to the search area. And they keep updating them as the planes approach the general search area so the pilots can make slight changes to their flight path. After all, the flights from Perth take 4 hours or so to get to the general search area, and so there is enough time for tracking the images and updating the pilots. I assume they are already doing something like this, but the pilots fly so high that they simply cannot spot anything visually? Even with the most sophisticated magnifying glasses? Also, the planes should be equipped with cameras to take higher resolution pictures of the search area? Finally, its been what over a week or so that these images have been spotted and are being tracked, so by this time ships also must be in the area and are also being fed the latest GPS coordinates? I mean how is it possible that the satellites are seeing all these objects, but the planes and ships see nothing? What am I missing here?

There is no real time tracking.

By the time satellite images are analysed and data passed on the debris would have moved another 1000 km.

Harpal Bector · Post by **Harpal Bector** » 27 Mar 2014 19:33

A_Gupta wrote:Breaking the INMARSAT symmetry:

It has been puzzling me - for each southern path that fits with the INMARSAT distance (angle over the horizon of the satellite from the plane) and Doppler information, there is a corresponding path that goes north. Basically, do a reflection across the geometrical plane that passes through the position of the satellite, the center of the earth, and the last mil. radar position of the aeroplane over the Gulf of Thailand.{A}

Only a little while ago it hit me that while the above is certainly true, a southern path of constant compass heading will not reflect into a northern path of constant compass heading.

The INMARSAT people must be operating on the assumption that the plane was on autopilot for the last 6-7 hours of its flight. Then, if the autopilot preserves a compass heading, the northern path and southern path are not symmetric, because the plane's path does not begin on the equator.

The thing that bothers me about that is the equator is an arbitrary line. As the satellite is stationary, it is only one point and for reference purposes the line joining the satellite with the last known point of the ac could be used as a reference instead of the equator. The difference in the shape of the Doppler offset shift with time for a northern path v/s southern path is interesting. This should simply be the component of the instantaneous velocity of the ac projected on to the vector joining the satellite to the ac. We can pick any point on the flight path as a reference, it doesn't have to be the equator.

I think they assumed a constant compass heading at 450 kts.

There are a lot of weird things about that plot. For example, the points are not equally spaced on the x-axis, there are 4 reported points in the first hour, then there is a huge gap of two hours and then we have one reported point on each of the NB and SB predicted flights, but we have three reported points (where it says "possible turn") in about 15 minutes for MH370. I wonder what that is about.

If the UKAAIB didn't want to be part of the presentation to the relatives, that suggests it has doubts about the validity of the analysis and did not feel comfortable with Malays extending the analysis to conclude that the ac was lost over the Southern IOR and that all passengers were dead.

A_Gupta · Post by **A_Gupta** » 27 Mar 2014 19:43

^^ For the autopilot, the equator is not an arbitrary line; the two poles and the lines of longitude defined with respect to the equator are what define a constant compass heading.

Lalmohan · Post by **Lalmohan** » 27 Mar 2014 19:49

correct, it is imaginary but still a reference line

Harpal Bector · Post by **Harpal Bector** » 27 Mar 2014 20:43

Assuming constant heading,and altitude, the dot product of the ac velocity and the vector joining the ac and the satellite has only one term that depends on the sign of the longitudinal velocity. This should impart a different curvature to the Doppler offset shifts for NB and SB paths even if the flights were on the same side of the equator. It is difficult to estimate the difference in curvature as I don't know the heading of the ac so I don't know its latitudinal velocity.

This same term also contains a portion that is proportional to the cosine of the inclination angle. That cosine would change sign as the ac passed the equator. As the path of the south bound ac crossed the equator, one would expect to see some impact of this on the observed offset shift. The last five points on the INMARSAT Doppler offset data should all be south of the equator and all points the NB path should be on the same side of the equator. This suggests that should see a feature in the predicted SB path that should be absent in the NB path. Maybe the shift between the green line and the red line at the fifth point at the beginning of the flight is this equator crossing in the SB path? The inability to precisely pin point the time at which ac crossed the equator may account for why the NTSB/Aus path calculations (5:11-8:11) are so clearly south of the equator.

But I could have made a mistake in that calculation, perhaps you can check it on Mathematica. I don't have a copy for personal use.

I started with the simplest expression for a velocity of the ac in spherical coordinates and then calculated the dot product with instantaneous displacement vector between the ac and the satellite. The constant altitude,and heading assumption fixes the radial components of the velocity to zero and makes the longitudinal and azimuthal velocity constant. I neglected the Coriolis effect and assumed that the airplane's autopilot was taking that out of play. The second derivative of the aforementioned dot product should give you the curvature of the Doppler offset shifts. This should allow one to construct the theoretical shifts for an ac that is NB or SB on a given speed, altitude and heading.

That being said whether the measured shifts had anything to do with the theory depends on the error budget of the various clocks.

Lalmohan · Post by **Lalmohan** » 27 Mar 2014 21:08

the aircraft need not have been flying at constant speed, height or heading
we don't know if AP was engaged and if so in what mode (heading mode is most likely, and as we saw from the manual that comes with vertical speed hold, not airspeed hold) so that might allow the forward airspeed to vary a little assuming 0 was set for vertical speed. the ground speed would defnitely vary depending on local wind conditions. the satellite would effectively be measuring aircraft ground speed since it is itself (almost) fixed over the ground

chaanakya · Post by **chaanakya** » 27 Mar 2014 21:31

Family Member Files Lawsuit Over Missing Jet as Frustrating Search Continues

A U.S. firm has initiated a lawsuit against Malaysia Airlines and Boeing over the Beijing-bound Flight 370 that disappeared over 19 days ago and is presumed to have crashed in the south Indian Ocean, killing all 239 on board.
More
Thai Satellite Spots More Clues as Bad Weather Hampers Search for Missing JetWhat the Missing Jet Tragedy Shows About China’s Attitudes toward Southeast AsiaMen Charged With Toppling Ancient Rock Formation Avoid Jail Time Huffington PostHere's An Updated Tally Of All The People Who Have Ever Died From A Marijuana Overdose Huffington PostMick Jagger to Inherit L'Wren Scott's $9 Million Fortune People

Chicago-based Ribbeck Law, which also represents 115 passengers aboard the Asiana Airlines Flight 214 that crashed in San Francisco in July, has filed a petition on behalf of Januari Siregar, whose son was on the Malaysia Airlines flight.

“We believe that both defendants named are responsible for the disaster of Flight MH370,” said Monica Kelly, lead lawyer on the case.

The petition is seeking to obtain the identity of manufacturers of various plane components and the company or person who last inspected the fuselage and provided maintenance. Kelly said additional pleadings will be filed against other potential defendants in the days to come.

Meanwhile, analysts are continuing to disseminate satellite data in order to pinpoint the wreckage. Based on signals sent out by the aircraft, officials reached the conclusion that the crash site was in the Indian Ocean. Now, a final partial signal from the aircraft is also being looked at for possible additional clues.

Chris McLaughlin, senior vice president of Inmarsat, the U.K. company that operates the satellite that picked up the signals, told the Wall Street Journal that this last transmission originated “with the aircraft for reasons not understood.”

Theo_Fidel · Post by **Theo_Fidel** » 27 Mar 2014 22:13

Harpal Bector wrote:I really wish the INMARSAT people would publish this as a short paper on the arxiv.

+1 to this.

I would be very curious to see what the error bars are on that Doppler estimate. It would not surprise if it is a 1-sigma signal. In which case the entire S. IOR is still open.

Precise numbers like 219.3 & 821 kmph are hard to believe.

Harpal Bector · Post by **Harpal Bector** » 27 Mar 2014 23:29

(okay now I see it - the word "speed" in my previous post is a typo - I will correct this).

I just tried to build the simplest model possible. The predictions for NB and SB ac are different and I want to know why that would be. If the simple model can predict that then that would be nice. In the simple model I assume that the satellite is fixed.

the dot product of the ac velocity and displacement between satellite and ac has the following terms (given above assumptions and here the subscript s to be the satellite and the ac is the symbols without subscript)

\vec{v}\cdot\vec{r_{sa}}= r*\dot{\theta}(\theta_s-\theta)+r*sin(\theta)*\dot{\phi}(\phi_s-\phi)

The observed Doppler shift in an ideal experiment should be proportional to this dot product. Here are three cases that the model points to.

**** case 1 - constant speed, heading and altitude****

if we assume
r*\dot{\theta}=c1 (a const).
and
r*sin(\theta)*\dot{\phi}=c2 (a const).

So the time derivative has the following terms

\dot(\vec{v}\cdot\vec{r_{sa}})=-c1*dot{\theta} -c2*(\dot{\phi})

If the sign of the longitudinal velocity changed (as would happen for NB v/s SB ac), the first term would not change sign as both the sign of c1 and \dot{\theta} would change.

The second term is indifferent to the sign of the longitudinal velocity and if \dot{phi} didn't change sign, the second term would not change sign as ac crossed the equator.

So this assumption does not give us the difference in curvature.

**** case 2 - constant heading and altitude****

If I relax the constant speed but keep the constant heading assumption (c1 and c2 not constant but c1/c2 = c is constant), then

\vec{v}\cdot\vec{r_{sa}}= r*\dot{\theta}(\theta_s-\theta)+r*sin(\theta)*\dot{\phi}(\phi_s-\phi)

\vec{v}\cdot\vec{r_{sa}}= [c*(\theta_s-\theta)+(\phi_s-\phi)]*r*sin(\theta)*\dot{\phi}

\dot(\vec{v}\cdot\vec{r_{sa}})=-[c\dot{\theta}-\dot{\phi}]*r*sin(\theta)*\dot{\phi}+[c(\theta_s-\theta)+(\phi_s-\phi)]*r*cos{\theta}*\dot{\theta}*\dot{\phi}+[c(\theta_s-\theta)+(\phi_s-\phi)]*r*sin(\theta)*(\ddot{\phi})

The first term will not change if the ac went from being NB to SB as both c and \dot{\theta} change sign.
The second term would change sign if the ac crossed the equator or if the it went from being NB to SB.
The third term would contain information about any Coriolis effect or wind.

This could show a difference in the curvature for NB and SB ac.

**** case 3 - constant altitude****

If I relax the constant speed and constant heading assumption (c1, c2 or c1/c2 are not constant), then I get more terms,

\dot(\vec{v}\cdot\vec{r_{sa}})=-r*dot{\theta}^2 + r*(\theta_s-\theta)*\ddot{\theta}+r*cos(\theta)*dot{\theta}*(\dot{\phi})*(\phi_s-\phi) +r*sin(\theta)*(\ddot{\phi})*(\phi_s-\phi) -r*sin(\theta)*(\dot{\phi})^2

The first term would not change sign if the ac went from being NB to SB.
The second term would contain information about any longitudinal acceleration the ac experienced such as due to wind etc...
The third term would change sign if the ac crossed the equator or if the it went from being NB to SB.
The fourth term would contain information about any Coriolis effect or wind.
The fifth term would depend only on the ac inclination angle and would not change if it went west or east.

This could show a difference in curvature for the NB and SB ac.

A_Gupta · Post by **A_Gupta** » 27 Mar 2014 23:31

^^^ Cut & paste formulas above into
http://www.codecogs.com/latex/eqneditor.php

for enhanced readability.

Harpal Bector · Post by **Harpal Bector** » 27 Mar 2014 23:38

Can't seem to use the editor to embed the equation

Harpal Bector · Post by **Harpal Bector** » 27 Mar 2014 23:49

I think previously I was not seeing the terms linear in \dot{\theta} and I kept ascribing the Doppler shift differences for NB and SB ac to terms containing \ddot{\phi} i.e. to Coriolis effects.

Vayutuvan · Post by **Vayutuvan** » 28 Mar 2014 00:14

Harpal ji, please use sagemath. It's interface is Python - much nicer language than Mathematica. sagemath is also free.

Vayutuvan · Post by **Vayutuvan** » 28 Mar 2014 00:19

A_Gupta: Your theory is very plausible. The question is for the constant compass heading the mirror image would be a great circle? That would put the final resting place of the A/C in w. Tibet, N. Af, Xinxiang. Should have passed through Indian and Pakistani radars. Since there is neither radar data nor any sightings (as in Maldivs), we have to assume that there is also some humint that makes the southern spur a higher probability for the powers that be.

ManuJ · Post by **ManuJ** » 28 Mar 2014 02:51

The first few turns of the flight are highly suspicious.
There's a possibility that the flight landed for a short while (in Malaysia/Indonesia region), offloaded the passengers, and then quickly took off again towards the deep end of the globe.
The pilot flying the second leg could have bailed out at a predetermined location.
The final location was chosen so that trying to find the (non-existing) dead bodies would be next to impossible.

member_22733 · Post by **member_22733** » 28 Mar 2014 03:29

Having designed some of these things in my previous life, let me chip in with some rusty half-assed knowledge. I am having some difficulty in understanding how symmetry is broken in case of a GEO sat.

Few questions I have been trying to dig up:

1) Is the communication completely digital, in which case there will be a diversity receiver on the satellite to estimate the signal being received?
2) What is the antenna characteristics of the satellite antenna? The arcs show some sort of circular symmetry in constant gain regions, is there anything more to that shape?
3) What is the Statistical channel model they used to model the signal path? it should include the doppler shift in its calculation. Examples: http://en.wikipedia.org/wiki/Radio_freq ... tion_model
4) If I could get my hands on it: Raw data from the antennas for each ping.

5) Strength of the radio wave leaving the plane.
6) PREVIOUS pings from the same plane, when it flew before on a well defined flight plan.

What can be done with that info?

The antenna model combined with the channel model will give you a most likely location, possibly a bunch of them. Since the channel model is likely to be symmetric around the equator (relative to a GEO sat), there will be mirror points all over. One could then speculate what happened, or use a Monte-Carlo plus Kalman filter combo to churn out a bunch of plausible paths with the available data. Even in this case, if the GEO orbit is true then one wont be able to distinguish between mirror paths (from the equator). I.e. The Monte carlo simulation would give you a perfectly symmetric distribution of possible paths centered at the equator. i.e. you need more data points to eliminate symmetry than just this.

So then the question is how did these folks arrive at different frequency offsets in the North Route and the South Route, and why are there only two predicted paths, why not four to maintain symmetry?

The only answer I can find is that they assumed the north path to be different from the south path. Based on either land features or some other data points that I missed (like if the south path was taken in the north instead, the plane would have run into the Himalayas etc).

I am still scratching my brains.

A_Gupta · Post by **A_Gupta** » 28 Mar 2014 04:25

LokeshC wrote:Even in this case, if the GEO orbit is true then one wont be able to distinguish between mirror paths (from the equator).

I think they assume that the plane was on autopilot on a constant compass heading starting from a point about 7° north of the equator. A southern path approaches, crosses and then recedes from the equator. A northern path only recedes from the equator. Yes, the plane could have turned around and gone north again as it crossed the equator, and be flown to give the same doppler and position readings as the southern path (provided, of course, it did not ping the satellite during the turn, the difference would not be detectable, I think.) But that violates the fundamental assumption that they made about the piloting of the plane.

Harpal Bector · Post by **Harpal Bector** » 28 Mar 2014 04:37

If you relax the constant heading assumption then I dont think you can interpret the doppler offset shifts.

The propagation of the wave between the ac and the satellite is treated trivially in the model I posted, I dont know what INMARSAT assumed.

I would really like to put some random numbers in for a NB and SB ac and see if the model predicts a hump for thr NB and a bowl shape for the SB doppler shifts.

INMARSAT should also comment on why there are 3 data pts in the MH370 data where the predictions one have one point each at same time stamp.

member_22733 · Post by **member_22733** » 28 Mar 2014 05:25

Harpal,

I did not get a chance to review your equations, but when the plane is on the north/south pole its directly moving towards (or away) from the sat, and will hence have the highest doppler shift. Similarly, when the plane is on the horizon of the sat (any tangent from sat to earth) point moving directly into or away from the sat, you should have max doppler shift.

Needless to say: On the equator directly under the sat: 0 doppler shift.

In short your equation should model the following (and can be roughly used to read the INMARSAT plots):
V1:
So if you cross hemisphere on a longitude, you will see a bowl. If you fly on a latitude, you will see a flat line. If you fly on a longitude in one hemisphere you will see an upward curve.
EDIT: The more correct version after some hair pulling:
V2:

Refer to the polar coordinate system below.

Imagine the satellite at the center of 2D polar cordinates. R, theta. At constant theta and varying R, you cross cross the longitude or latitude of the sat, you will see a bowl. If you fly around a circle (constant R, varying theta) around the sat, you will see a flat line. If you increase R you will see an increase in the offset.

All of the above assuming constant velocity of the plane (this is also the same assumption made by INMARSAT and they have mentioned it to be 450knots on their graph heading). The plot would change into a more complex one (cylindrical co-ordinates) if the plane velocity was to be included as well.

We can interpret this in another way as well: There is a circular symmetry in the relationship with radial component of the airplane velocity in the 2D co-ordinate system and the doppler shift/freq offset.

Your equation should ideally take into consideration ONLY the radial component (should not depend on theta).

Polar coordinate system:
http://upload.wikimedia.org/wikipedia/c ... s_plan.png

http://upload.wikimedia.org/wikipedia/c ... er.svg.png

EDIT: Added later
If you want a outline to derive some of this stuff:
1) Figure out equation to map any airplane velocity (speed, direction) from Global co-ordinates to the 2D polar co-ordinates.
2) The 'radial component' of the velocity should be the dot product of the "satellite to airplane" vector and airplane velocity (remember that this includes direction as well). This is in the global co-ordinate system. Basically its a projection operator.
3) This radial component is the only thing that causes the doppler shift which should be AFAIK directly proportional to the burst offset that they plotted.
Once you have that you can reverse engineer a lot of things (for ex. what circle would cause a burst offset of 100).

UlanBatori · Post by **UlanBatori** » 28 Mar 2014 06:06

So it's nearly 20 days, and dozens of ships and planes have been searching all-out, and trying to find things "seen" by satellites. Total blank. Is the weather so bad there that helicopters cannot operate, or that pilots cannot see down?
How can they have not found ANY of the things seen from satellites?

member_22733 · Post by **member_22733** » 28 Mar 2014 06:09

A_Gupta wrote:
LokeshC wrote:Even in this case, if the GEO orbit is true then one wont be able to distinguish between mirror paths (from the equator).
I think they assume that the plane was on autopilot on a constant compass heading starting from a point about 7° north of the equator. A southern path approaches, crosses and then recedes from the equator. A northern path only recedes from the equator. Yes, the plane could have turned around and gone north again as it crossed the equator, and be flown to give the same doppler and position readings as the southern path (provided, of course, it did not ping the satellite during the turn, the difference would not be detectable, I think.) But that violates the fundamental assumption that they made about the piloting of the plane.

Ahh.. that assumes no hijacking then

. They should consider symmetry IF there was hijacking. While the chance of it being a hijacking are approaching zero with every new piece of evidence, it is NOT zero yet, and in that case there should be 4 potential paths and not 2.

sadhana · Post by **sadhana** » 28 Mar 2014 06:32

On CNN Piers Morgan they say Australia has moved the search area by 1100km to the northeast? based on 'new analysis of radar data' which includes a higher estimate of the aircraft's speed.

shiv · Post by **shiv** » 28 Mar 2014 06:41

UlanBatori wrote:So it's nearly 20 days, and dozens of ships and planes have been searching all-out, and trying to find things "seen" by satellites. Total blank. Is the weather so bad there that helicopters cannot operate, or that pilots cannot see down?
How can they have not found ANY of the things seen from satellites?

You yak herders should not be so disdainful of satellite images. remember that it was satellites that discovered Iraq's nuclear weapons.

member_28502 · Post by **member_28502** » 28 Mar 2014 06:51

No it was Aluminium tube filled with Yellow pound cake dough that confirmed Iraqi Nooklier weapons

Singha · Post by **Singha** » 28 Mar 2014 07:22

I doubt anything will be recovered at the rate its going. govts cannot keep pouring money indefinitely.

we did the wise thing by grounding ourself in subaya malaysia instead of flying on to perth. I hope our two planes have already returned back.

sadhana · Post by **sadhana** » 28 Mar 2014 07:24

http://www.amsa.gov.au/media/documents/ ... date23.pdf

Search operation for Malaysia
Airlines aircraft: Update23

The search area for missing Malaysia Airlines flight MH370 has been updated
after a new credible lead was provided to the Australian Maritime Safety Authority
(AMSA)
.
As a result today’s search will shift to an area 1,100 kilometres to the north east based on updated
advice provided by the international investigation team in Malaysia.

The Australian Transport Safety Bureau (ATSB), Australia’s investigation agency, has examined this
advice and determined that this is the most credible lead to where debris may be located.
The new search area is approximately 319,000 square kilometres and around 1,850 kilometres west of Perth.

The new information is based on continuing analysis of radar data between the South China Sea and the
Strait of Malacca before radar contact was lost. It indicated that the aircraft was travelling faster than previously estimated, resulting in increased fuel usage and reducing the possible distance the aircraft travelled south into the Indian Ocean.

ATSB advises the potential flight path may be the subject of further refinement as the international
investigativeteam supporting the search continues their analysis

A_Gupta · Post by **A_Gupta** » 28 Mar 2014 07:46

sadhana wrote:http://www.amsa.gov.au/media/documents/ ... date23.pdf
The new information is based on continuing analysis of radar data between the South China Sea and the
Strait of Malacca before radar contact was lost. It indicated that the aircraft was travelling faster than previously estimated, resulting in increased fuel usage and reducing the possible distance the aircraft travelled south into the Indian Ocean.

What they're saying is the plane was flying faster between 1:21 AM and 2:15 AM = 54 minutes, enough to reduce its range by 600+ miles?

http://www.smh.com.au/national/missing- ... 35nco.html

The shift in focus for investigators is surprising as it follows the release of new satellite images from French and Thai satellites that showed a large amount of debris moving progressively south of where a US satellite originally located debris - including some objects larger than 20 metres - almost two weeks ago.

shiv · Post by **shiv** » 28 Mar 2014 07:47

Nijalingappa wrote:No it was Aluminium tube filled with Yellow pound cake dough that confirmed Iraqi Nooklier weapons

This confirms the efficacy of high resolution satellite imagery in guiding actions on the surface of the earth.

A_Gupta · Post by **A_Gupta** » 28 Mar 2014 07:48

http://www.smh.com.au/world/missing-mal ... zqnzf.html

Kuala Lumpur: A senior AirAsia pilot has been suspended for suggesting in a Facebook post Malaysian authorities have been “hiding facts” about the disappearance of MH370.

shanth · Post by **shanth** » 28 Mar 2014 07:48

vina wrote:
shanth wrote:I have worked on Sat modems before, including those that talk to Inmarsat satellites. The modem on the airplane will receive the signal from the satellite and use it to remove its own oscillator drift, just like your cell phone does right now. Only thing left is doppler due to speed. No magic here, standard stuff
Great ! Can you take a few minutes here to explain how it actually works ? It will be nice to have a good understanding of it.How does the cellphone actually work ? If you are using the cellphone while driving a car, how does the cellphone handle the doppler shift that gets induced because of it's own motion wrt to the tower and how does the tower handle the doppler shift from the handset's motion when it is receiving ?

I guess the initial protocol when a call is connected will be a handshake that includes details such as I (the tower) will be transmitting at freq X, while the handset sends back at another channel at freq Y sort of thing ? I suppose the inmarsat will be something similar ?

First attempt:
* Background:
Your typical cell phone has a VCO which has the following sources of drift:
1ppm/year due to age. PPM = parts per million = 1e-6.
2.5ppm/ for temperature variation from -35C to +85C
0.3 ppm

* Maximum design caters per design to design but the approx is around 5ppm.
Notice that the ppm due to age can be estimated and removed over time by saving the offset in some storage
5ppm at 1.5GHz = 7500Hz.

* So each cell phone on when it powers on (and does not yet communicate to the base-station) can see an error of 7500Hz.

* Sat modems can use the same VCO. Sat modems have other problems that the satellite is not actually stationary for LEO, and is moving a little bit for GEO. GEO sat's are not fully stationary... but there are techniques for this, so lets ignore for now.

* Now when the cell phone power's on, it locks on to the base-station signal and modifies its own VCO based on the frequency from the base-station. For a stationary cell phone (no cell phone doppler), now the cell phone VCO is perfectly synchronized

* For a moving cell phone, the total frequency offset seen is the sum of the frequency error due to its own VCO offset and the frequency error due to its own motion. The cell phone cannot differentiate between the two. It simply corrects for the sum of both. This causes the VCO to be off from 'truth' by the amount equal to doppler of the cell phone.

* The cell phone now transmits to the base-station. The error seen by the base-station is twice the doppler error. The initial transmission to the base-station is a special signal whose properties have been chosen such that the base station can find the signal even with a large doppler and timing offset. Notice that only the 2xDoppler error is seen and not the error due to the cell phone's VCO offset.

* This correction is relayed back to the cell-phone. The correction is applied to the very next transmission and all is well.

* Small modifications for satellite's to account for satellite motion etc, specially designed signal properties and all is well there as well.

A_Gupta · Post by **A_Gupta** » 28 Mar 2014 07:49

Japanese satellites see debris too!
http://zeenews.india.com/news/world/jap ... 20755.html

Tokyo: Japanese satellite images have shown around 10 floating objects off Australia, possibly from missing Malaysia Airlines Flight 370, media reports quoted the government as saying on Friday.

The objects were spotted in waters roughly 2,500 kilometres southwest of Perth, Kyodo and Jiji news agencies said.

Japan's Cabinet Satellite Intelligence Centre's study showed objects up to eight metres in length and four metres wide in images captured by a satellite between 9 am and 3 pm (local time) Wednesday, Kyodo said.

member_28502 · Post by **member_28502** » 28 Mar 2014 07:56

Sighting Debris has become common even Badr1 is citing debris

Now why would Malaysian PM ask Pakis help in missing plane search.
Here it is plane and simple in language

In 2001, the Pakistan Academy of Sciences held the physics and mathematics conference on astrophysics in Pakistan where scientists from all over the country were invited to come to Nathiagali. In an media interview given at Nathiagali, dr. Abdul Qadeer Khan maintained that, "Pakistan has very robust nuclear I.R.B.M. system which can launch geostationary orbiting satellites. All Pakistan has to do is to erase Delhi or Calcutta from the target and point it towards the sky. Instead of Hydrogen bombs and Atomic bombs, the missiles can easily carry a payload of a 80kg satellite into the sky...". Astrophysicist dr. Shahid Kureshi also argued that [IRBM] missiles have very robust and effective electronics and computer system, the [SLV]s used the similar technology. Taking part in this discussion, Nuclear physicist dr. Pervez Hoodbhoy believed that "If we [Pakistan] can launch a missile up to a range of 1,500 km, why not build an [SLV] that can launch low-atmosphere satellites?".

Maan liye janab, pareshan hothe huae Aadab kheta huan ji

A_Gupta · Post by **A_Gupta** » 28 Mar 2014 08:34

11:38 AM Perth, Australia time - press conference, talking about the change of search area.

Benefits of the new search area: better weather, ocean depth between 2000-4000 meters instead of 6000m, closer to Perth, so planes get more time to search.

My addition - no pesky satellite images. An official said in essence that satellites see a lot of things that are not real.

----
One thought - The plane was flying till 8:11 AM at least; if it was flying faster during that time then it covered more distance between 2:15AM - 8:11AM than previously thought. This has to be more than compensated for by less time of flight after 8:11AM, otherwise I don't understand how the plane is further north.

CRamS · Post by **CRamS** » 28 Mar 2014 08:40

I am watching the press conference now. Two points clear so far:

1. All the previous search areas are being junked
2. This new search area, 684 miles N of original search area is closer to Perth, and this area is not just a potential debris field, but actual location where they believe the plane actually crashed

A_Gupta · Post by **A_Gupta** » 28 Mar 2014 09:02

So if the plane flew 50 kmph faster for 6 hours (2:15 - 8:11 AM) that adds 300 km, but then maybe it had less fuel to continue after 8:11AM, e.g., if it flew half an hour less, that would subtract 450 km, for a net of 150 km.

Then, if the plane was travelling faster, and is still consistent with INMARSAT arcs, that would push the trajectory to the south and west, as in the below (yellow is the 450 knot flight path, red is the 400 knot flight path).

Or
http://forums.bharat-rakshak.com/viewto ... 0#p1615883

So I simply don't get this. No matter how fast the plane ran through its fuel the flight has to have ended on or south of the blue-green arc.

-- further, the plane travelled a fixed distance - IGARI-VAMPI-GIVAL-headed to IGREX in 56 minutes - I don't understand what they mean by the plane travelled faster than thought or slower than thought. It could have travelled at a lower altitude, I suppose for a given speed (above given distance by above given time) flying at a lower altitude, the plane would use more fuel. But that is not what they say.

The governments of the world for some reason are yanking our chains. At this point outer Mongolia seems like the height of civilization - all information about yak collisions is promptly published on the mongolia.gov web-site.

PS: Ulan Batori, you were misinformed. That monkey may have quit the post of Pakistan's Air Chief; but that monkey is not retired; that monkey is heading the MH370 crash investigation.