Title :
Reduced minimum configuration fiber optic gyro for land navigation applications
Author :
Emge, S. ; Bennett, S. ; Dyott, R. ; Brunner, J. ; Allen, D.
Author_Institution :
Andrew Corp., Orland Park, IL, USA
fDate :
4/1/1997 12:00:00 AM
Abstract :
Further cost reduction of the fiber optic gyroscope is necessary to meet the economic requirements of land navigation systems. Previous concentration was on the reduction of the number of splices and component improvements in the open-loop minimum configuration. Now non-essential components and splices are eliminated. The source-detector coupler is not part of the Sagnac interferometer, and serves solely to direct light from the interferometer into the output photodetector. Many commercial laser diodes incorporate a back-facet photodetector to monitor laser intensity. The signal returned from the Sagnac traverses the laser, and can be detected at this photodetector. The gyro signal can be distinguished from the laser signal by the bias modulation applied in the interferometer. Configuring a gyro in this manner eliminates a directional coupler and the separate photodetector, as well as up to two fiber splices in an all-fiber gyroscope. A production, open-loop fiber optic gyroscope has been modified to demonstrate this principle. The gyroscope exhibits performance comparable to the conventional minimum configuration
Keywords :
Global Positioning System; fibre optic sensors; gyroscopes; light interferometers; navigation; optical fibre couplers; optical fibres; AUTOGYRO Navigator; Allan variance analysis; GPS coupled; Sagnac interferometer; all-fiber gyroscope; back-facet photodetector; bias modulation; bias remperature sensitivity; cost reduction; dead-reckoning sensor; economic requirements; fiber optic gyroscope; land navigation application; open-loop; reduced minimum configuration; source-detector coupler; Costs; Diode lasers; Fiber lasers; Gyroscopes; Navigation; Optical coupling; Optical fibers; Optical interferometry; Photodetectors; Sagnac interferometers;
Journal_Title :
Aerospace and Electronic Systems Magazine, IEEE