Jason Robert Moore

US Patent:

6545760, Apr 8, 2003

Filed:

Mar 24, 2000

Appl. No.:

09/535659

Inventors:

Mark E. Froggatt - Yorktown VA
Jason P. Moore - Newport News VA

Assignee:

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC

International Classification:

G01B 902

US Classification:

356477, 356 355

Abstract:

An apparatus and method for measuring strain in an optical fiber using the spectral shift of Rayleigh scattered light. The interference pattern produced by an air gap reflector and backscattered radiation is measured. Using Fourier Transforms, the spectrum of any section of fiber can be extracted. Cross correlation with an unstrained measurement produces a correlation peak. The location of the correlation peak indicates the strain level in the selected portion of optical fiber.

US Patent:

7538860, May 26, 2009

Filed:

Aug 17, 2007

Appl. No.:

11/840363

Inventors:

Jason P. Moore - Yorktown VA, US

Assignee:

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC

International Classification:

G01L 1/24

US Classification:

356 355, 356478

Abstract:

A system and method for determining a reflection wavelength of multiple Bragg gratings in a sensing optical fiber comprise: (1) a source laser; (2) an optical detector configured to detect a reflected signal from the sensing optical fiber; (3) a plurality of frequency generators configured to generate a signal having a frequency corresponding to an interferometer frequency of a different one of the plurality of Bragg gratings; (4) a plurality of demodulation elements, each demodulation element configured to combine the signal produced by a different one of the plurality of frequency generators with the detected signal from the sensing optical fiber; (5) a plurality of peak detectors, each peak detector configured to detect a peak of the combined signal from a different one of the demodulation elements; and (6) a laser wavenumber detection element configured to determine a wavenumber of the laser when any of the peak detectors detects a peak.

US Patent:

7813599, Oct 12, 2010

Filed:

Feb 23, 2009

Appl. No.:

12/390606

Inventors:

Jason P. Moore - Yorktown VA, US

Assignee:

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC

International Classification:

G02B 6/00
G01L 1/24

US Classification:

385 13, 385 12, 385 37

Abstract:

A method of determining the shape of an unbound optical fiber includes collecting strain data along a length of the fiber, calculating curvature and bending direction data of the fiber using the strain data, curve-fitting the curvature and bending direction data to derive curvature and bending direction functions, calculating a torsion function using the bending direction function, and determining the 3D shape from the curvature, bending direction, and torsion functions. An apparatus for determining the 3D shape of the fiber includes a fiber optic cable unbound with respect to a protective sleeve, strain sensors positioned along the cable, and a controller in communication with the sensors. The controller has an algorithm for determining a 3D shape and end position of the fiber by calculating a set of curvature and bending direction data, deriving curvature, bending, and torsion functions, and solving Frenet-Serret equations using these functions.

US Patent:

20140053654, Feb 27, 2014

Filed:

Aug 22, 2012

Appl. No.:

13/591320

Inventors:

Matthew D. Rogge - Norfolk VA, US
Jason P. Moore - Yorktown VA, US

Assignee:

U.S.A as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC

International Classification:

G01L 1/24

US Classification:

73800

Abstract:

Shape of a multi-core optical fiber is determined by positioning the fiber in an arbitrary initial shape and measuring strain over the fiber's length using strain sensors. A three-coordinate p-vector is defined for each core as a function of the distance of the corresponding cores from a center point of the fiber and a bending angle of the cores. The method includes calculating, via a controller, an applied strain value of the fiber using the p-vector and the measured strain for each core, and calculating strain due to bending as a function of the measured and the applied strain values. Additionally, an apparent local curvature vector is defined for each core as a function of the calculated strain due to bending. Curvature and bend direction are calculated using the apparent local curvature vector, and fiber shape is determined via the controller using the calculated curvature and bend direction.