Missing 777

[k0ua]

I keep wondering why these ships hearing the pings at close to freq. there listening for. first a weak and keeps getting stronger then weaker and lost again.
Why doesn't a ship that has a signal just stop or go in circle trying to locate direction of the signal?
Maybe the recording is on a tape and not read until ship is back in harbor.
Person listening jiust happened to go eat lunch while the pings are present.

Then a Chinese ship with a microphone on a pole over the side can hear the signal. but not know location. ?

On occasion working for power co. there would be a compliant of noise on power line. a small antenna and receiver could locate area and then moving forward and back could locate a broken insulator. arcing.

I know the water currents and bottom of ocean may block signals but if one is being received why not keep it located.
ken

Ken, I don't know much about underwater ultrasonic sound propagation, but If you will read this link, you will discover that it is an extremely complicated subject. And narrowing down and finding the source of an underwater signal is not near as easy as locating an RF emitter in the air. Not that Radio Direction Finding is all that easy at times either, but this underwater direction finding is really something else.! Pay particular attention to the section on propagation of sound.

https://en.wikipedia.org/wiki/Underwater_acoustics

 

[k0ua]

I don't know you, but now I understand why I read all of your posts in every forum with great interest!! :thumbsup:

Don't humor him. Kinda like feeding the giraffe at the zoo. He won't go away.....

Ha ha... honestly I feel sort of the same on James. Not the giraffe part, but the interest.

Oh, don't get me wrong, I think James is extremely intelligent and I always pay attention to what he says. Now,,, we just gotta not tell him I said that. I'll let you in on a secret..... He's kinda fruity.... I'm not talking about his sexual persuasion. I'm talking about Mangos and Coconuts.... And he's from Missouri. No wait, scratch that part.

Oh Richard, you know you like me, Mango's and all
Thanks for the kind words everyone..

 

[buickanddeere]

Good point there but with GPS tech you can mark your spot within 10 feet and return. I use my simple MOB (man over board) function on my Garmin portable Nav equipment to find my shrimp pots in the fog.

Receiver is 3000meters below the surface. How is it going to receive a GPS signal?

 

[dragoneggs]

Receiver is 3000meters below the surface. How is it going to receive a GPS signal?

Well now you are taxing my knowledge, but if you know where you are and you know how much line is out and approximate angle of the drag you can get a pretty good idea of where... can't you? I hope our guys operating the equipment know a heck of lot more than that! :confused3:

 

[Ken]

I knew I was out of my element when asking why the frequency could not be located. Ever swim in a large pond with rocky sides and some one slaps two rocks under water. knew two rocks had been hit but not direction it had come from.
Then read the articlle on underwater tracking and Navigation Says Unlike most radio signals which are quickly absorbed.
sound propagates far underwater and at rate that can be precisly measured or estimated.

There was a comment of not being able to turn a ship with 2 miles of cable strung out. I agree think they said the ship was traveling 3MPH.
stopping wouldn't be that difficult.
Does it hear the signal but cannot tell the incoming direction?

Just trying to understand the coming and going of a constant signal.
ken

 

[robbyr]

I was wondering if cabbage eating whales might possibly contribute to the global warming farce as do flatulating cows.

 

[k0ua]

Not that anyone is probably all that interested but this morning when I posted earlier with the waterfall photos I left the radio on sitting on 14.070Mhz and this software collects all of the decoded callsigns that my station has heard for this approximately 12 hour period and sends them in real time to a website, you can click here if you would like to see them. The dark parabolic shadow is the earths terminator (or shadow) as my location is now in darkness. If you loiter your mouse over the ballons you can see the callsign and location of each of the stations I decoded. Keep in mind it does this all by itself, I was out on the tractor and working on my wife's park bench project today.
Below is the screen shot of the intercepts map. I figure we might as well post something while we are waiting to find out what happened to flight MH370. Because we don't know much yet!

 

[texasjohn]

James, now that's just way out cool, I don't care what anybody says, you win the cool post of the month!

 

[texasjohn]

Dan,, just wondering how you came to have such expertise in all subs for all nations?

But only the US and the UK regularly send subs on missions. The Russians used too but now it is a big deal when the send a sub to sea and they are lucky the sub does not sink. The Chinese subs are worse than the Russian subs and some do not leave the dock at all though the Chinese are rabidly gaining skills in operations and building. They play for the long game. I doubt any sub leaving Russia or China is not followed by a US sub. That used to be true in the Cold War at least and I would really be surprised if a Chinese sub can leave the First Island Chain with out having a US sub following.

Later,
Dan

 

[farmgirl19]

James, now that's just way out cool, I don't care what anybody says, you win the cool post of the month!

^^^^^^^^^^

What he said!