Originally Posted by slip and turn
Coagie makes a good point. If you are seriously interested in effective research I recommend learning a few quick-win effective research techniques so you don't have to bash fellow PPRuNers for their sources! E.g. start with Google and a few well chosen search words like AF447 acoustic locator sonar frequency.
Then in seconds you might easily stumble over stuff like:
BEA to examine why acoustic sweep missed AF447 recorders - 5/5/2011 - Flight Global
https://fenix.tecnico.ulisboa.pt/dow...issertacao.pdf
Slip and turn, none of these links nor the ones I found make as strong a statement as Coagie did, that the submarine search was ineffective because they were simply unaware of the signal being sought.
However that second link is quite interesting. I had not seen it; thank you for including it.
Coagie, there is a big difference between not knowing what signal to look for and adjusting the sensors settings / filtering / noise suppression, whatever, to improve the sensor range. Further, none of the sources I found indicate that the reanalysis of the tapes actually _did_ locate the signal. It appears it gave them a new search possibility that did not pan out, unless it was the basis of the phase 3 search.
Michelson interference? As in the Michelson-Morley experiment on the speed of light that demonstrated the lack of an ether (or that by a coincidence we happen to be stationary relative to the ether... always wondered why they discounted that possibility so readily -- okay only being tongue-in-cheek here
). I'm not quite sure what that has to do with underwater acoustics...