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[Paphitis]

where do the state that? And what is BTO? Do you mean BFO instead?

Read your link start to finish!

BTO = Burst Timing Offset. It's what they used to determine the direction of flight towards or away from the Satellite and this value was recorded down to the microsecond.

[Pyrpolizer]

To determine the direction they have to use the BFO and that's irrelevant of the timing.
I will try figure out what they mean by BTO and how that could possibly be used.
Perhaps I will crunch the numbers down and see what happens.

[Pyrpolizer]

Well, I tried my best, but I cannot figure out whether their Burst Time offset is a calculated value or a measured one or a combination of the two.
It's accuracy would only matter if it was a measured value!

Everybody who is familiar with complicated electronics knows their response time is never accurate, and fluctuates according to many external variables. Even identical electronic devices respond differently,because the components are never absolutely identical, resistors, capacitors everything has tolerances.
So perhaps what they mean by "burst offset" is some calculated difference. Satellite companies do keep log files for this specific reason, to make adjustments to their systems.
Still though those "Bust offset" timings contain the time and hence distance information as to how far away the plane was. Assuming the BTOs were actually calculated then the accuracy of the planes distance remains unknown.

I also tried to check if the BTOs were actually measured values.
The 14820 mc secs at pre take off, would be a perfect measured value because it corresponds to 4,640 Km which is roughly the distance from Kuala Lumbur to the satellite.But then again Inmarsat says that their BTOs are actually the total(?) times needed for the signal to travel from the plane to Satellite, then to ground station, then from ground station back to satellite and then back to the plane PLUS the processing times which are constant but not provided. Also where the hell is the ground station, at London???
Hence not possible to confirm if they were measured values from from that either.

[Paphitis]

Inmarsat have many ground stations all over the world.

There is one in Western Australia at a place called Geraldton near Perth. There is probably another on the East Coast.

That site is also an Echelon site along with Pine Gap and part of an integrated network that spans the globe and also includes Agios Nikolaos which is a British Station in Cyprus.

That suggests that Inmarsat have a number of Australian Defence Contracts and is an approved supplier. They must also have security clearances.

Geraldton is also a Ground Station for some Australian and US military spy Satellites. A lot of very top secret shit there.

I know there is another Ground Station in Canberra but I do not know if Inmarsat are on this site.

They are not on the Pine Gap site which is one of the most infamous installations on the planet.

[Kikapu]

Then the search party began looking too far south, and meanwhile the debris would be drifting up to 200 kms per day. By now, any surviving debris could be half way across the globe. It could be anywhere. It's not that hard to understand.

I'm sure you meant to say on average 40 Km per day (24 hrs). Sea currents can be anywhere from 0.5 knots to 1.5 knots, averaging at 1.0 kts. Tidal currents can be very high in certain parts of the world, but that’s another subject than normal sea currents. At best, we would sail about 300 Km in a 24hr day.

If we take the 7th pings position and the +-300Km as given, that still leaves time and distance traveled by the aircraft after the 7th ping. Lets take the worst-case scenario, that after the 7th ping the aircraft traveled another 59 minutes at 900Km per/hr before crashing into the ocean just before the 8th ping. Add the +-300Km, now you are looking at as much as 1200Km from the 7th ping. But supposing the plane made a directional change after the 7th ping and did not continue flying south but instead flew East, North or West. Now the Area to be searched can be as much as 1,440,000 sq/km from the 7th ping if my calculations are correct.

Question. We know the pings from the engines are sent once an hour, but when does the hour start? Is it when the engines are turned on or is there a specific time when the hour start? Secondly, does the pilots know this information? In other words, would the pilot of MH370 have known when the 7th ping was sent by the engines so that he can then change course from the 6th and 7th pings, assuming the MH 370 was flying in the same direction between those two pings, of course?

Also, can the pilot physically disconnect the cockpit voice recorder and the data recorder, making the Black Boxes completely useless with no useful information at all if they were ever to be found, other than information left to the point of the cut off. Since other important instruments were turned off, one would expect the same to have been done to the Black Boxes too if it was physically possible, no?

[Paphitis]

Then the search party began looking too far south, and meanwhile the debris would be drifting up to 200 kms per day. By now, any surviving debris could be half way across the globe. It could be anywhere. It's not that hard to understand.

I'm sure you meant to say on average 40 Km per day (24 hrs). Sea currents can be anywhere from 0.5 knots to 1.5 knots, averaging at 1.0 kts. Tidal currents can be very high in certain parts of the world, but that’s another subject than normal sea currents. At best, we would sail about 300 Km in a 24hr day.

If we take the 7th pings position and the +-300Km as given, that still leaves time and distance traveled by the aircraft after the 7th ping. Lets take the worst-case scenario, that after the 7th ping the aircraft traveled another 59 minutes at 900Km per/hr before crashing into the ocean just before the 8th ping. Add the +-300Km, now you are looking at as much as 1200Km from the 7th ping. But supposing the plane made a directional change after the 7th ping and did not continue flying south but instead flew East, North or West. Now the Area to be searched can be as much as 1,440,000 sq/km from the 7th ping if my calculations are correct.

Bottom line is that the + or - 300kms does not exist because all times were to the microsecond.

However, there would be other errors, such as the calculations from Boeing.

At the end of the day, they authorities know all about their error margins and delineate a search area accordingly.

Question. We know the pings from the engines are sent once an hour, but when does the hour start? Is it when the engines are turned on or is there a specific time when the hour start? Secondly, does the pilots know this information? In other words, would the pilot of MH370 have known when the 7th ping was sent by the engines so that he can then change course from the 6th and 7th pings, assuming the MH 370 was flying in the same direction between those two pings, of course?

I can't answer that because I do not know.

No, the pilots do not know anything about it or when the ACARS data is captured. It just is every 5 minutes or so.

Also, can the pilot physically disconnect the cockpit voice recorder and the data recorder, making the Black Boxes completely useless with no useful information at all if they were ever to be found, other than information left to the point of the cut off. Since other important instruments were turned off, one would expect the same to have been done to the Black Boxes too if it was physically possible, no?

No the pilots can't do that.

[Paphitis]

Basically, the error from the transmission between Aircraft, Satellite and Aircraft would be about + or - 300m.

However, after the 7th ping, MH370 would have travelled some distance before the Flame Outs, and from there it would have glided quite some distance before actually ditching.

At 450 knots = 7.5 nms/min. Therefore, if the aircraft flew for 30 minutes before the flame out it would have travelled approximately 225 nms + the Glide Distance before ditching.

Aircraft Performance Analysts would be able to calculate the amount of Fuel on Board remaining at the time of the 7th ping and they would also be able to calculate an approximate Ground Speed and the Glide Distance from FL350.

MH370 would still maintain the same heading unless interfered with by another human which would not be the case if all on the aircraft were already dead. So based on that assumption, they can determine an approximate most likely area of impact.

There are errors which they would be aware of or would take into consideration which is why they have declared a Search Area of some 56000 sq kms.

[Pyrpolizer]

Neither the +-300 Km are correct nor the +-300m
The BTO's are a sum of other values including the unknown constant of processing time.The processing time is a computer value that can be measured ANY time (even today) and be added to the other values.If that value is to the microsecond and the other values are to the millisecond the end result will be to the microsecond. This doesn't add to the accuracy required.

So we have 2 possibilities here
a)All values were actually measured to the microsecond
b)The microsecond "accuracy" just came out because the computer processing time was to the microsecond.

If A is correct
--> then we have to look at known measurements.The best ones would be those at pre -take off. We notice there is a fluctuation in readings from 14780 to 14920 microsecs. that's a total of 140 microseconds which corresponds to 42Km or +-21Km
This error comes just from false/fluctuated readings, other errors like those due to temperature, humidity etc might have influenced the readings after take off to make their +- range bigger. (how much bigger I don't know)
if B is correct
--> then the +-300Km is correct.

For the sake of discussion we have to accept that A is correct.Otherwise the whole thing would be total junk.
Let's continue:

What concerns me more is the Frequency offset.
Again if we take the pre take off measurements we have readings ranging from 84-90Hz. And that's when the plane was not even moving!
This gives an additional 9.3% error in DIRECTION OF MOVEMENT or a +-4.6%. This translates to +-40 Km in position from one handshake to the other. And unfortunately in this case the error is cumulative because they consider the position established at ping 4 to estimate the position at ping 5 and so on. Therefore from ping 4 to ping 7 we have another +-160Km cumulative error.
So the total error would be +-181km. Fortunately this error is not distributed evenly. Mathematicians could of calculate the odds, and could come up with workable results. They could for example estimate there is a 50% possibility the plane would be within say +- 40Km away from estimated position and only 1% possibility to actually be at the limit of +- 181Km away from the estimated position.

That much concerning the accuracies.

Just because i ve spent some time looking at those data you might be interested to know the following info:
I got totally confused as to which one was actually the 7th ping. If you consider the data at pre take off there have been at least 10 communications...
Anyway looking back at the BFOs diagrams, ping 4 seems to have been defined as the one that occurred exactly 4 hours after take off at 20:41. (Take off was at 16:41)
From there on we had one partial handshake at 00:19 (let's call it ping 8 who's data in my opinion just constitute false readings) and another Ping a few seconds later which they called "last transmission from aircraft terminal" let's call it ping 9 with even more obvious false readings.
Total flight time upto ping 7 was 7 hours 29 minutes, and if we consider the other 2 pings it was 7 hours 38 minutes

Just out of curiosity I punched the numbers in and made a preliminary graph (assuming 0% error in data) of the distances from satellite to the plane.The graph could be used to check Inmarsats arcs.

[Paphitis]

No each ping is standalone! They are measuring the BTO from Aircraft to Satellite and back to the Aircraft to calculate a distance from the Satellite placing the aircraft somewhere along an arc equal to the distance from the Satellite.

Not that they discount the previous pings, because that is not the case at all. The reason for this is that the previous pings give us valuable clues such as the distance travelled in the given 60 minute intervals and hence they can get a Ground Speed and so on.

The accuracy of the arc would depend entirely on the accuracy of the clocks and if the data is collected down to a microsecond, then we are talking about a + or - 300m error margin.

The big errors come in to play when the actually reconstruct the flight. As with everything it is the human element which is the weakest link and not the Inmarsat Satellite.

The area where MH370 went down is influenced by the Subtropical Jetstream. Winds are easily as high as 200 knots. This wind is usually a Westerly so most of it would be a Crosswind. There will only be a slight Headwind or Tailwind Component. Drift would be considerable.

The Performance Engineers would be trying to establish all these parameters including the Track, Heading, True Airspeed, Ground speed, Power Settings, Fuel Consumption, Outside Ambient Temperatures at 35000FT, Mach Number, Configuration (Drag) and all the permutations in between which are too numerous to mention here (if I did, then this post would be endless). This is where the big errors will occur. Even if all the assumptions are correct, accuracies can only be + or - 5% at best. Might even be as much as 10% out because, in reality, they do not have a starting point. All they got is the last confirmed Primary return, and maybe they have some other information if they are lucky but are not revealing it because they are not allowed to. For instance, it is a possibility that the aircraft was detected at some point by Australia's JORN. What is interesting is the fact that when the search shifted from the South China Sea to the Malacca Straights, the Royal Australian Navy already began to search the Southern Indian Ocean and a few days after this, Inmarsat reveals information concerning the 7 Handshakes and confirming that the Indian Ocean was the most probably impact area. My guess is that aside from the Inmarsat data, there is additional information, from military sources which are assisting the IIT.

Additionally, there was some speculation that the United Nations might also have some information. Too early to say whether this will be a good lead or not.

[Pyrpolizer]

No each ping is standalone! 1 They are measuring the BTO from Aircraft to Satellite and back to the Aircraft to calculate a distance from the Satellite placing the aircraft somewhere along an arc equal to the distance from the Satellite.

Not that they discount the previous pings, because that is not the case at all. The reason for this is that the previous pings give us valuable clues such as the distance travelled in the given 60 minute intervals and hence they can get a Ground Speed and so on.

The accuracy of the arc would depend entirely on the accuracy of the clocks and if the data is collected down to a microsecond, then we are talking about a + or - 300m error margin. 2

The big errors come in to play when the actually reconstruct the flight. As with everything it is the human element which is the weakest link and not the Inmarsat Satellite.

The area where MH370 went down is influenced by the Subtropical Jetstream. Winds are easily as high as 200 knots. This wind is usually a Westerly so most of it would be a Crosswind. There will only be a slight Headwind or Tailwind Component. Drift would be considerable.

The Performance Engineers would be trying to establish all these parameters including the Track, Heading, True Airspeed, Ground speed, Power Settings, Fuel Consumption, Outside Ambient Temperatures at 35000FT, Mach Number, Configuration (Drag) and all the permutations in between which are too numerous to mention here (if I did, then this post would be endless). This is where the big errors will occur. Even if all the assumptions are correct, accuracies can only be + or - 5% at best.3 Might even be as much as 10% out because, in reality, they do not have a starting point. All they got is the last confirmed Primary return, and maybe they have some other information if they are lucky but are not revealing it because they are not allowed to. For instance, it is a possibility that the aircraft was detected at some point by Australia's JORN. What is interesting is the fact that when the search shifted from the South China Sea to the Malacca Straights, the Royal Australian Navy already began to search the Southern Indian Ocean and a few days after this, Inmarsat reveals information concerning the 7 Handshakes and confirming that the Indian Ocean was the most probably impact area. My guess is that aside from the Inmarsat data, there is additional information, from military sources which are assisting the IIT.

Additionally, there was some speculation that the United Nations might also have some information. Too early to say whether this will be a good lead or not.

1--> each ping stands alone concerning the BTOs in drawing an arc from the satellite.Then you need the BFO to cross that arc and establish a position. To establish next position you have to rely on the previous one therefore while the error from the BTOs is constant the error from the BFOs is not and sums up for each ping.
2-->It would be nice if it were to the microsecond exact. However if you notice all BTOs end to a zero which turns their accuracy to 10 microseconds which in turn increases the distance from +-300m to +-3Km.Then you have to take into consideration that your readings themselves do not reflect absolute reality. From pre take off BTOs you can see there is a fluctuation in readings of as much as 140 microseconds.Therefore the error from BTOs alone gets up to +-21 km. This is relatively small and more importantly it is constant.The error of the BFOs however is double than that and on top of it is not constant but cumulative from at least the 4th ping onwards.
3-->imagine what would happen if you add that extra 5%