Digitally processed, phase-reading fibre gyroscope

We present a simple digital processing method that provides ii significant improvement for the performance of a phase-reading open-loop fibre-optic gy roscope. The phase reading gyroscope measures the angular speed in terms of a phase difference between the two counter-propagating beams in the Sagnac interferometer. Instead of electronic phase meters we use a very simple PC -based digital process which computes the Sagnac phase. With this method we measure rotation rates down to 100 degrees h(-1). The errors of this schem e are studied for different signal-to-noise ratios and the number of bits o f the analog-to-digital converter. (C) 2000 Elsevier Science Ltd. All right s reserved.