Abstract: A dithered Coriolis acceleration sensor system has a proof mass that is free of feedback in the accelerometer servo loop at the dither frequency by totally notching out all feedback torque at this frequency. The proof mass relative motion is then a direct measure of the rate because there is no feedback torque to alter the proof mass response to the acceleration. The feedback modulation system according to the invention captures the Coriolis-sensor output such that the phase and gain of the signal generated from the sensor are of no concern in maintaining good scale factor.

Abstract: A dithered Coriolis acceleration sensor system has a proof mass that is free of feedback in the accelerometer servo loop at the dither frequency by totally notching out all feedback torque at this frequency. The proof mass relative motion is then a direct measure of the rate because there is no feedback torque to alter the proof mass response to the acceleration. The feedback modulation system according to the invention captures the Coriolis-sensor output such that the phase and gain of the signal generated from the sensor are of no concern in maintaining good scale factor.

Abstract: A digital controller produces control data signals for application to each of three fiber optic rotation sensors in a triaxial rotation sensing system. The digital controller also produces strobe signals corresponding to each fiber optic rotation sensor. The digital controller sequentially provides first, second and third strobe signals that activate the analog converters sequentially to apply modulating signals to the three fiber optic rotation sensors. The system further includes apparatus for providing modulation cycles to keep all three fiber optic rotation sensors active simultaneously. Sampling apparatus samples each sensor sequentially during a .tau. period and feedback modulation control data signals are applied sequentially to the three sensors during the .tau. period for each sensor when the sensor was sampled. Feedback modulation control data signals are isolated from each fiber optic rotation sensor except for the .tau. periods in which it is sampled.

Abstract: An amplifier topology for receiving signals output from a fiber optic rotation sensor and producing voltages that may be processed to determine the rotation rate includes a photodiode for receiving an optical signal and producing a corresponding electrical photodiode output signal. An ultra low noise and ultra low capacitance differential input stage is connected to receive the photodiode output signal. An operational amplifier having low noise and ultra-wide bandwidth is connected to the ultra low capacitance differential input stage to receive the output signal therefrom as a driving signal and to produce a low noise output signal. The differential input stage comprises a first amplifier circuit that includes a first transistor connected to the photodetector to act as a first buffer having low noise, low capacitance and unity gain.