1. Fiber Optic Gyroscopes Instrumentation: Sensors and Signals

2. History Developed in the 1980s as an alternative to Laser Ring Gyroscopes. ▫ More compact ▫ Less sensitive

3. Comparison and applications

4. WHOI Puma

5. How does a RLG work? Based on the Sagnac effect, like the FOG

6. Basic FOG configuration

7. Classical explanation Basics Variation in wave vectorWave vectorPhase shift

8. Classical explanation Phase difference Using Geometry

9. Classical explanation Integrating phase difference along the path length

10. FOG Equation Angular wavenumber

11. Relativistic Explanation *Only correct if the detector is moving with the gyroscope

12. Open loop configuration with phase modulation

13. Analog signal implementation

14. Analog circuit implementation

15. Signal Processing Used

16. Digital circuit implementation Digital signal processing apparatus. First to forth heterodyne mixers (2, 3, 4 and 5), an ADC (6), a timing pulse generating unit (7), a cosine/sine signal generating unit (8), first and second digital multipliers (9, 10), first and second digital filters (11, 12), a quadrant discriminating unit (13), an angular velocity computing unit (15), a phase modulation index computing unit (14) and a reference signal generating circuit (1).

17. Digital circuit implementation Digital signal processing apparatus. First to forth heterodyne mixers (2, 3, 4 and 5), an ADC (6), a timing pulse generating unit (7), a cosine/sine signal generating unit (8), first and second digital multipliers (9, 10), first and second digital filters (11, 12), a quadrant discriminating unit (13), an angular velocity computing unit (15), a phase modulation index computing unit (14) and a reference signal generating circuit (1). 3 2 1 4 Isolate different harmonics

18. Digital circuit implementation Digital signal processing apparatus. First to forth heterodyne mixers (2, 3, 4 and 5), an ADC (6), a timing pulse generating unit (7), a cosine/sine signal generating unit (8), first and second digital multipliers (9, 10), first and second digital filters (11, 12), a quadrant discriminating unit (13), an angular velocity computing unit (15), a phase modulation index computing unit (14) and a reference signal generating circuit (1). 4 5 Digital Filter  Low pass => DC component kept

19. Digital circuit implementation Digital signal processing apparatus. First to forth heterodyne mixers (2, 3, 4 and 5), an ADC (6), a timing pulse generating unit (7), a cosine/sine signal generating unit (8), first and second digital multipliers (9, 10), first and second digital filters (11, 12), a quadrant discriminating unit (13), an angular velocity computing unit (15), a phase modulation index computing unit (14) and a reference signal generating circuit (1).

20. Digital circuit implementation Digital signal processing apparatus. First to forth heterodyne mixers (2, 3, 4 and 5), an ADC (6), a timing pulse generating unit (7), a cosine/sine signal generating unit (8), first and second digital multipliers (9, 10), first and second digital filters (11, 12), a quadrant discriminating unit (13), an angular velocity computing unit (15), a phase modulation index computing unit (14) and a reference signal generating circuit (1).

21. Digital circuit implementation Digital signal processing apparatus. First to forth heterodyne mixers (2, 3, 4 and 5), an ADC (6), a timing pulse generating unit (7), a cosine/sine signal generating unit (8), first and second digital multipliers (9, 10), first and second digital filters (11, 12), a quadrant discriminating unit (13), an angular velocity computing unit (15), a phase modulation index computing unit (14) and a reference signal generating circuit (1).

22. Quantum Theoretical Performance Limit,,, Theoretically

23. Sources of nonidealities Nonreciprocity – differences in the optical paths of the counter propagating waves Polarization Backscattering Magneto-optical Faraday effect

24. Case Study: RA2100 (KVH Industries)

25. Source: ftp://ftp.uni-duisburg.de/Hardware/KVH/ec2k-b.pdf

27. Case Study: RA2100 (KVH Industries)