Communications – electrical: acoustic wave systems and devices – Receiver circuitry
Patent
1981-07-28
1983-06-14
Farley, Richard A.
Communications, electrical: acoustic wave systems and devices
Receiver circuitry
367 20, 367130, 367901, 367154, G01S 380
Patent
active
043887112
ABSTRACT:
An apparatus for rejection of turbulence induced flow noise for towed hydhone arrays. Two adjacent hydrophones in the array are spaced less than flow noise coherence distance apart forming a flow noise cancelling module. The inverted acoustic/flow noise signal from the lead hydrophone of the pair is split, one side passing to the final stage of signal processing while the other side, filtered, amplified and inverted, is added to the combined signal from the lag hydrophone which has been filtered and amplified. The acoustic signal components cancel leaving only the lead hydrophone flow noise plus the lag hydrophone flow noise which has been shifted by a factor dependent upon tow vessel speed and hydrophone spacing. This flow noise signal is then combined in an adder-inverter with the delayed feedback from the output stage of this same adder-inverter, cancelling the lag hydrophone flow noise leaving only the flow noise of the lead hydrophone which is then combined with the acoustic signal plus flow noise output of the lead hydrophone. The flow noise components cancel yielding only the signal of interest, free of flow noise and undistorted by minor phase shifts.
REFERENCES:
patent: 1584613 (1926-05-01), Comstock et al.
patent: 2368953 (1945-02-01), Walsh
patent: 3071752 (1963-01-01), Strasberg
patent: 3281767 (1966-10-01), Cryar
patent: 3299397 (1967-01-01), Pavey, Jr. et al.
patent: 3436722 (1969-04-01), Strange
patent: 3795873 (1974-03-01), Fein et al.
patent: 3860899 (1975-01-01), Watlington
patent: 3922488 (1975-11-01), Gabr
patent: 4025724 (1977-05-01), Davidson, Jr. et al.
patent: 4091358 (1978-05-01), Bayhi
Beers Robert F.
Farley Richard A.
Lall Prithvi C.
McGill Arthur A.
The United States of America as represented by the Secretary of
LandOfFree
Optimum flow noise cancelling hydrophone module does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optimum flow noise cancelling hydrophone module, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optimum flow noise cancelling hydrophone module will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-167691