Radiant energy – Photocells; circuits and apparatus – Optical or pre-photocell system
Patent
1998-02-10
1999-09-28
Westin, Edward P.
Radiant energy
Photocells; circuits and apparatus
Optical or pre-photocell system
356345, G01B 902
Patent
active
059592940
ABSTRACT:
A technique for interrogation of fiber optic interferometric sensors wherein an optical signal is modulated by an array of fiber optic sensors in response to acoustic pressure. Modulated signals (channels) from each sensor are multiplexed onto a single fiber optic cable and the multiplexed signal is input to a polarization diversity detector having at least two outputs. The optical signal is converted into a digital, electrical signal. A plurality of digital down converters demultiplex and demodulate the separate channels and output in-phase data and quadrature phase data for each of the signal channels. A system controller connects to the digital down converters and to a calibration digital down converter. The calibration digital down converter, controlled by the system controller, mimics an operation of each digital down converter in turn in order to determine optimal digital down converter settings for each digital down converter. The system controller updates the optimal settings for each digital down converter such that the digital down converters are dynamically calibrated according to the optimal settings. The in-phase and quadrature phase data output of the digital down converters are then processed with an acoustic signal processor.
REFERENCES:
patent: 4649529 (1987-03-01), Avicola
patent: 4752132 (1988-06-01), Pavlath
patent: 5448058 (1995-09-01), Arab-Sadeghabadi et al.
patent: 5555086 (1996-09-01), VonBieren et al.
Homodyne Demodulation Scheme for Fiber Optic Sensors Using Phase Generated Carrier, Anthony Dandridge, Alan B. Tveten and Thomas G. Gaillorenzi, IEEE Journal of Quantum Electronics, vol. QE-18, Oct. 1982.
TMC2330A Coordinate Transformer 16 X 16 Bit, 50 MOPS, Raytheon Electronics Semiconductor Division, Stock# /ds7002330A, Jun. 1997.
GC40414 Quad Receiver Chip Datasheet, Gray chip, Inc., Graychip DSP Chips and Systems, Dec. 1, 1997.
Ferraro Eugene L.
Green James D.
Hershman Lawrence J.
Litton Systems Inc.
Pyo Kevin
Westin Edward P.
LandOfFree
Method and apparatus for interrogation of fiber optic interferom does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for interrogation of fiber optic interferom, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for interrogation of fiber optic interferom will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-706148