Method and apparatus for overcoming cross-coupling in a fiber optic gyroscope employing overmodulation
CA 2202433 A1 · Owner: Litton Systems Inc. · Inventors: Tazartes, Daniel A.; Cordova, Amado; Mark, John G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A phase modulator applies sequences of artificial phase shifts in the region of overmodulation between light beams counterpropagating within the sensor coil of a Sagnac interferometer to obtain improved random walk performance. The sequences are composed of phase shifts of ~a.pi./2b and ~(4b-a).pi./2b where a is an odd integer and b is an integer greater than 1. The waveform for driving the phase modulator is derived from a 2.pi. radian mapping plotted so that adjacent driving signal values differ by a.pi./2b or -(4b-a).pi./2b in a first angular direction and by -a.pi./2b or by (4b-a).pi./2b in the opposite angular direction. Angular transitions about the mapping may be predetermined to …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed April 11, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 11, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 11, 2019.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.