Fig. 1. Filtering effect evaluation of Kalman filter under different g values. (a) Output results after filtering under different g values; (b) standard deviation of output result of filter varying with g value

Fig. 2. Time response evaluation of Kalman filtering under different g values. (a) Response of filter to step signal under different g values; (b) t₉₀ response time varying with g value

Fig. 3. Normalized standard deviation and t₉₀ varying with g value and corresponding exponential function fitting

Fig. 4. Relationship between R value and g value under different Gaussian white noise amplitudes

Fig. 5. Relationship between R value and g value under different weights

Fig. 6. Filtering effect evaluation of Kalman filter on outliers. (a) Response of Kalman filtering to outliers under different g values; (b) comparison of 10-point and 20-point moving average filtering with Kalman filtering

Fig. 7. Comparison of response of Kalman filter and extended state filter to concentration step signal

Fig. 8. Schematic diagram of ammonia slip laser detection system

Fig. 9. Flow chart for inversion of gas temperature, concentration of H₂O and concentration of NH₃

Fig. 10. Comparison of measured results of ammonia slip laser detection system with and without Kalman filtering. (a) 108×10-6 NH₃; (b) 4.7×10-6 NH₃; (c) concentration of indoor water vapor ; (d) temperature of indoor gas