Quantization reduction for evaluating laser gyro performance using a moving average filter

Ring Laser gyro performance is typically evaluated by measuring the random walk in angle associated with each instrument over a range of operating and environmental conditions. However, the ring laser gyro, being basically a digital sensor, outputs accumulated angle in quantized pulses. This quantization in the presence of dither has a similar effect on gyro test data as white noise in angle. To reduce the effect of quantization and dither on gyro test data, so as to enable the random walk coefficient of the instrument to be determined to high precision in short times, a high speed Moving Average Filter (1 kHz) was developed which outputs accumulated gyro data samples once per second. The quantization noise power is reduced by a factor greater than 512 and the dither is reduced by a factor greater than 200 db while the random walk characteristic is virtually unaffected. The following describes the operation of this Moving Average Filter, analyses its effect on gyro test data and presents test results.