The possible landing or crashing zone of MH370 (PIC):

[morningfog]

That is a lot of land and water to check.

[brooklynite]

1. ...but this isn't accurate.

You need to draw a SECOND arc around the last reported point of the plane, reflecting it's maximum flight distance (reduced by the the apparent flight at lower altitude). From what I understand, the the plane MIGHT have made it to a location in India, but certainly not into the 'Stans.

[BlueStreak]

5. But there is no evidence of low altitude

The only "evidence" of that is that nobody admits to having such a plane on their radar.

But I question the whole premise of the arc in the first place. This is all based on an antennae reading from a geostationary satellite that is flying 22,000 miles above the earth. The satellite supposedly gives out a reading that says what the optimal antennae angle would have been for that message. So this is all claimed based on the slightest difference in angles to a satellite satellite 22,000 miles above us.

This sounds like the old axiom, "Never confuse precision with accuracy." And dumbass engineer with a slide rule can make up an equation to "prove" that curve matches the last ping, but I don't believe there would be anywhere near the accuracy that the chart implies.

That chart smells like "baffle them with bullshit" to me.

[jakeXT]

8. I think they used the military radar positions and the satellite pings

To check if the satellite data is correct. I believe it was.

[jakeXT]

7. They have a satellite ping every hour, combined

with the speed you could get more interesting results. Also the reports of cellphones being connected should be checked. If you are on land it should be possible to find the country.

[NightWatcher]

2. So, it could've landed in BENGHAZI?!?

I knew Obama did it.

[countryjake]

3. NBC news tonight said that Navy was preparing to scale back search...

as are several other nations, due to the tremendous expending of resources.

They said that the Navy was going to return to normal military operations, dedicating only a couple of specialty aircraft to aid Australia with their search operation in the south Indian Ocean this week.

Determined detective work will now be the focus of discovering what may have caused Flight 370's disappearance.

Judging by that report, it sounds to me like the plane is lost for good.

[Art_from_Ark]

4. But I thought the plane crossed back over Malaysia

and then headed northwest, toward the Bay of Bengal

[BlueStreak]

6. I think the last reliable radar reading was the initial turn away from Vietnam

It seems that shortly after that maneuver, the plane was off radar and to my knowledge, no reliably confirmed radar information has been reported after that point. For a few days, there were reports that the plane was on radar in the Strait of Malacca, but apparently that wasn't true.

ALl they are talking about now is that bogus satellite arc that doesn't represent a flight path. it only purports to identify the possible location s of the plane when the last ping was received. And I am dubious of that whole claim in the first place. I don't believe you can get that kind of accuracy from a satellite 22,000 miles above the earth. We'd be talking thousandths of a degree. That sounds like crap to me.

That's the kind of chart bureaucracies whip up when they can't or don't want to answer the real questions.

[jakeXT]

9. The military radar was true and it fits with the satellite pings/nt

[BlueStreak]

10. The satellite pings show little about location

The margin of error for a satellite in geosynchronous orbit (that's 22,000 miles up) is large. There is no place the plane could have flown for an hour after the first turn that would not be within the margin of error for the satellite. That satellite is not for location sensing. It is for communication. They are trying to infer location through tricky geometry, but it cannot tell us very much.

And if it could actually tell us anything reliable, then we should be looking at the "arc charts" for each of the separate hourly pings, not just the last one. That would give some insight into the possible flight paths.

[jakeXT]

11. I agree about the hourly pings. But the flight towards the satellite from east to west should have

at least resulted in a shorter response time.

[BlueStreak]

13. It isn't based on response time

It is based on the satellite's determination of what the optimal antennae angle would have been to have received the ping. Think of the geometry. The long side is 22,000 miles. The short side is claimed to be a difference of about 150 miles (the claimed accuracy). This means that the antennae offset would have to be accurate to 10ths of a degree. I doubt that, considering that it is a short message that passes through all the layers of the atmosphere.

A wise man once told me "Never confuse precision with accuracy." I suspect this is one of those cases.

[jakeXT]

14. As I understood it, they have both angle and time

1) Look at the time delay for transmission of the signal to the satellite. This would give you a range from the sub-satellite point if measured accurately enough, which would be a circle on the Earth’s surface.
2) Measure the power level of the signal as received at the satellite. The antennas on the satellite and the plane amplify the signal more at some elevation angles than others. If you know the transmission power accurately enough, and know how much power was received, you can estimate the angle it came from. This again would produce a similar range from the sub-satellite point, expressed as a circle on the Earth’s surface

http://www.airtrafficmanagement.net/2014/03/mh370-satcoms-101/

[BlueStreak]

15. Time relative to what?

For the system you describe to work, the plane's clock would have to be accurate to the microsecond, and I seriously doubt that. I believe it is a simple ping, not a more sophisticated round trip message that might be able to infer times (but still not to the degree that would support the accuracy on that chart.) After all, it was just intended to be an "I'm still here" message. I don't think it was ever intended to be used this way. Some engineers are trying to do some clever geometry to try to help (or dis-inform, depending on what their organization's agenda is.) I just caution against taking this chart at face value.

If those calculations have any validity at all, then why are they not showing us the charts for EACH of the hourly pings? Why do they show only the last one? If you could see the steps in the middle, that would probably tell us one of two things:

a) the actual flight path could not have proceeded along that arc or

b) there is no way to get from point A to point B using these theoretical calculations.

Whenever a person in possession of a lot of data provides only a tiny fraction of it, I become very suspicious.

[jakeXT]

17. Round trip time, I guess you get an acknowledgment package

A Ping is a quite common term for IT Networking. It refers to a utility used to test the reachability of a host on an IP network and measure the round-trip time (RTT) of the packets even if it is more frequently associated to the data messages themselves, or “pings”.

Similarly to what happens on a Local Area Network, satellites send pings (once a hour) to their receiving peers that respond to it thus signaling their network presence. Hence, these pings are no more than simple probes used to check the reachability of SATCOM systems aboard the planes.

http://theaviationist.com/2014/03/16/satcom-acars-explained/

[BlueStreak]

18. The ping in this case is iniated by the aircraft.

As far as I know, it is a one-way message. For there to be reliable timing, you would need i-1/2 trips. Plane to Sat, Sat ack to plane and plane ack to sat.

But you would never be completely certain about the processing time at the plane, and every microsecond delay might throw off the calculations by 10 miles or something.

I don't dispute that a person can take the data from the satellite, construct an equation, and plot a curve.

I only dispute the accuracy and relevance. But accuracy and relevance are kinda important. And again I ask, If the data is all that accurate, then why don't they show us the arcs for EVERY hourly ping?

[jakeXT]

19. I don't know who initiates it, I have also read that the satellite starts it

Last edited Tue Mar 18, 2014, 02:33 PM - Edit history (1)

When an aircraft powers up, the plane automatically sends a signal logging onto the communication network. After that, CNN reported, the ground station sends "polling signals" to the satellite, which relays them to the aircraft. When the plane responds, it is known as a "handshake".

http://www.straitstimes.com/breaking-news/se-asia/story/missing-mh370-how-satellites-communicate-plane-malaysia-airlines

A lot of people have the data, but it's not out there in the open

"Today, based on raw satellite data that was obtained from the satellite data service provider, we can confirm that the aircraft shown in the primary radar data was flight MH370. After much forensic work and deliberation, the FAA, NTSB, AAIB and the Malaysian authorities, working separately on the same data, concur," says Razak

http://www.newscientist.com/article/dn25232-data-transmission-system-on-mh370-deliberately-disabled.html#.UyiFH4VWhZA

[BlueStreak]

20. Interesting. But it still leaves the question of how accurate the timing can be

And again when we are talking about inferring geometry from a point 22,000 miles above us, every millisecond translates to a big margin of error.

In IP networks, ping time is reported in milliseconds and a deviation of 5-10 milliseconds isn't unusual at all. But that traverses a bunch of network hops. In this case, presumably the plane transmits directly to the satellite, but I still believe there would be a significant margin of uncertainty, and those curves look may too pat to me.

Again, if we were to see the curves assembled for each hourly ping, I think it would be easier to make judgments as to how meaningful that data might be. If we are to believe this methodology is valid, then the hourly pings should chow clearly whether there was significant east-to-west movement of the plane throughout the flight. It can't really show north-south movement, hence the concept of an arc. But the east-west movement is vital to eliminating some of the scenarios.

For example, if there were convincing information that the plane never really deviated much from that arc, that makes it EXTREMELY implausible the plane was heading north because it would have passed over countries like China, India and Pakistan, and the chances of doing that undetected are very low.

But for all we know, the plane could have headed west over the Arabian Sea and then inland to a landing somewhere along that arc. That is entirely plausible and by looking at only the final data point we learn very little. They have the other data points. Why have they not released that? Why have they released on the last data point?

[hobbit709]

12. Chances of it getting past Chinese military radar undetected are practically zero.

[BlueStreak]

16. Chances of the Chinese telling us the truth about that aren't much higher.