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Arran
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22 Mar 2014, 6:46 am

Are there any experts in radar systems on WP?



michael517
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22 Mar 2014, 8:55 am

I did some work with radars from foreign countries in the 1990's, but I wouldn't call my self an expert.

I had a great book on radars from an expert, Lord knows if I could dig it up. The author of the book gave a one day class on the subject.

A true expert could do all the math on transmit power, reflection, lobing, receive power, noise figure, all that, I would be hard pressed to do that.

What's the question?



Arran
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22 Mar 2014, 4:44 pm

There's a very interesting theory by Keith Ledgerwood that MH370 switched off its transponders then changed course to enter the flightpath of aircraft SIA68 that was flying from Singapore to Spain. MH370 caught up with SIA68 then flew very close by, possibly on top of it, across the Bay of Bengal. When both aircraft entered the airspace of India they showed up as one single blip on the primary radar and only the transponder information of SIA68 would be received by air traffic control and the military tricking them into thinking that there was only one aircraft rather than two. Both aircraft proceeded across India and into the airspace of Pakistan whilst all the time showing up as just one on radar and ATC transceivers. Somewhere over Turkmenistan or Kyrgyzstan out of the range of radar the two aircraft split away from each other. SIA68 continued flying to Spain and MH370 was landed in some remote part of Central Asia or China. These final locations are a perfect match up with the 7.5 hours of total flight time on the northern curve generated using the pings of data received by Inmarsat.

http://mh370shadow.com/

I'm looking for somebody with enough knowledge of the radar systems used in India and Pakistan to be able to determine whether it is realistically possible for a Boeing 777 to hide in the radar shadow of another aircraft. What would be the minimum separation distance between two objects before they are resolved as two objects on a radar screen?



eric76
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22 Mar 2014, 5:30 pm

I see absolutely no credible reason to think anything but that they had an in-air emergency and ended up crashing into the ocean somewhere.



sliqua-jcooter
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22 Mar 2014, 5:32 pm

It may be possible from a radar perspective, but Inmarsat would have detected it. The plane started in the footprint of the pacific satellite, which coverage extends to just west of India.

If the plane had flown the flight path suggested, it would have handed off to the East EU satellite and that would have been detected by Inmarsat.


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eric76
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22 Mar 2014, 7:23 pm

sliqua-jcooter wrote:
It may be possible from a radar perspective, but Inmarsat would have detected it. The plane started in the footprint of the pacific satellite, which coverage extends to just west of India.

If the plane had flown the flight path suggested, it would have handed off to the East EU satellite and that would have been detected by Inmarsat.


Not only that, it would have to land at a major airport. At least, it would if there was to be any possibility of ever taking off again. Land a 777 on a runway not specifically designed to handle really large aircraft and it would probably sheer off the landing gear with a fair chance of crashing the entire aircraft. The safest way to land would be to not extend the landing gear and go in for a belly landing.

If it landed at any major airport, it would most probably have been seen and reported. It's kind of hard to hide a 777.



Arran
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23 Mar 2014, 1:41 am

Can you confirm this? Do you have concrete proof that there are no suitable landing sites in remote locations in China or central Asia?



eric76
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23 Mar 2014, 1:57 pm

Arran wrote:
Can you confirm this? Do you have concrete proof that there are no suitable landing sites in remote locations in China or central Asia?
If you think that there are such places, please tell us where they are.

Remember that for any suitable landing site, it would have taken an enormous amount of construction to make the runway. Typically, a runway capable of carrying a jumbo jet is going to be heavily reinforced concrete three to four feet thick and that concrete is going to be a very high quality.

It would be relatively simple to check every such airport by satellite. Remember that not only would the aircraft have to have landed, it would then have to be hidden. That would be anything but an easy task.



Eccles_the_Mighty
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24 Mar 2014, 3:33 pm

You're confusing two different types of technology.

Radar will give you the moving dots on the screen and enable the Air Traffic Controllers to see where an aircraft is in three dimensional space. Even if an aircraft doesn't have a transponder there will still be a moving dot on the screen and if two aircraft get too close those dots will merge into one. No matter what the pilots do they cannot stop their radar trace appearing on the screen (unless they are a stealth aircraft).

A Transponder on an aircraft contains two devices, a receiver and a transmitter. The receiver listens for the radar signal and when it's received it transmits back a quick data burst to Air Traffic Control. This data burst contains the flight number, a four digit identification code and the aircraft's height. No matter how close two aircraft get the Air Traffic Controller will ALWAYS see BOTH transponder flags, even if one is displayed on top of another and if they get too close both transponder flags will flash on the radar screen. Rumour has it that the transponders on MH370 were disabled by somebody pulling the circuit breakers in the cockpit.


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