Originally Posted by DJ77
mm43,
Quote:
"the SSCVR ULB finished up getting itself half buried"
Do you know that for a fact ?
One thing that surprised me was the statement that the pingers could only be detected by TPLs at a bit more than 1700m. Important variables necessary to asses the valididy of this statement are missing: I couldn't find acurate specifications for the TPLs on the net. Another essential variable was the noise intensity spectrum level around the pingers frequency. In this frequency band I think that rainshowers and, to a lesser degree the sea state play a major role. But rainshowers randomness may make detection rely on luck.
I think that mm43 is referring to the photo that BEA published of the CVR, showing the pinger half-buried. I am less sure than mm43 about the configuration of the transducer in the pinger case, and what the effect on the sound level would be of the way the pinger landed on the bottom.
I gave an approximate estimation of the the pinger detection range in this post:
http://www.pprune.org/5683946-post951.html
Rain would have some influence at 37kHz. I don't know if it was raining when they searched the now-known debris area. According to the classic text by Robert Urich, there is a 20db difference between the minimum and maximum ambient noise in the deep ocean, between calm and 30knts wind (sea state 0 and 6). I expect that rain is added to that, but light rain does not add much, as near as I can tell. I assumed about sea state 2-3 in my calculation.