According to CNN "expert", if the Chinese ship is towing the array at the surface and the wreckage is at the bottom there is no way it could hear the pinger. 4400 m depth.....plus no contact with Malaysia or AUS since the original report???? Something is not adding up....

Could it be that another ship emitted the signal in order to calibrate their detectors? How else can you check that the equipment is working properly?

They might be picking up an interference pattern caused by underwater mountains. Towing the sonar rig in a grid pattern at a consistent depth and creating a map of the signal strength might give them a better picture of where the side lobes and main lobe of the signal lies.

Astounding this goes from the Chinese->media instead of to the search team.

If I did something like that during a search my ticket would be punched pretty quickly.

methodology of towed search
 

It has been asked why not stop? The answer is that, aside from the practical considerations of a tow, a stationary detector provides no useful information. The 90 sec interval gives an idea of the wreckage being on a line perpendicular to the tow route corresponding to the middle of the 90 sec interval.

The technique would be to circle wide through 270 degrees and survey along the line just mentioned to hopefully detect over an interval thus producing another line. Approach this crossing point from a third direction between the other two to create a third line. The result of the three lines is known as a cocked hat and gives an idea of the position of the source. If the signal strength is measurably variable then the maximum strength gives a position for the perpendicular line.

The signals can be distorted by sea bed features and thermal/ salinity features in the water column.

Just watching that CCTV You tube link.

She said that the ship detected the same signal on Friday for 15 minutes but were unsure because there were other ships in the vicinity. Then they heard it at 4:00pm Beijing time today for just 90s. Now if they didn't record today. Did they record it yesterday? Something is a miss here. I'm afraid there seems to be no reports of this on Friday. I smell a sensationalist media release like their sat photos last month turned out to be. Was that XINHUA as well?:bored:

Is it known what depth this Chinese black box detector was being towed at?

Seems quite fundamental

Watch the report in Post #9286 again.

The reporter states that China and Australia authorities had been notified.
No surprise Malaysia is quiet, Australia is supervising this.

Why the surprise ?

Western media reps have been present on numerous flights.

If this vessel is ploughing its own furrow miles away from the main search sites, I'd say it was highly unlikely they would be detecting a 'test tone' from another ship.

I would also like to think that anyone generating 37.5KHz anywhere near other search vessels, would let everyone know when and for how long they were doing it.

I guess towed arrays come in many different forms, but the ones I've seen were in tubes filled with a paraffin-type substance to give them neutral buoyancy.

sorry Pontius Navigator

devices are made in differing types and can descend below the surface or some types stay on the surface
both can set to listen at different depths etc etc

so a 4000m cable you suggest ? - of course a surface sonar would not hear it

also re wreckage the OP was responding to my original post where i stated
If the MH370 had crashed in that region then any floating small wreckage will be soon reaching the shores of Western Australia due the prevailing weather and sea conditions

seems you may not been reading the whole thread either

According to one report, debris has /had been reported in the area. Perhaps they were investigating that?

https://uk.news.yahoo.com/missing-pl...1.html#QZGXWSG

Crikey there's come cynical folk posting. So they've possibly found something, great news.

Perhaps the Chinese vessel was relocating from one search area to another? If it was out-of-area, there are lots of innocent explanations why.

what happens if this is the FDR/CVR and the Chinese get hold of it - who then undertakes the data/tape play back and investigation??

Absolutely right! However if you look at the device used it looked very much like a single hydrophone.

The American detectors are being towed by HMS Echo and HMAS Success. HMS Echo has sidescan sonar and specialises in ocean survey including sea bed. She has been used extensively in the Mediterranean (agreed much shallower) to successfully find wrecks.

@catch 21

I see your point - but in that case why towing equipment which has been said many times to be very slow? Wouldn't you want to reach the other side ASAP? Or is it common to keep on surveying on route to another search side?

I am not claiming any conspiracy but it seems that it is quite unusual, indicating that as we all know there is probably more info we do not know about.

If they have found something it would be great in any case!

@catch21
I've been surprised at the cynicism and hostility, too. If they've found something, great.

Even if they were out of area, which is rather speculative at the moment, personally I'd rather that they were out of area and found something than in area and didn't...

Anything discovered relative to airplane parts will belong to Malaysia. They have the legal right to determine what happens to them, and who gets them, when,and how.

Oops, and Seacom made the pingers for MH370:ugh:

Chinese working in isolation
 

Over the past 10-15 days I've been checking in with marine traffic (AIS) for the region. While not definitive, when I have seen a Chinese patrol or research vessel declared to be SAR, they have not been in the designated search areas.

It appeared that at least some Chinese assets were "on their own".