Fig. 1. Corrected atmospheric total spectrum curve of oxygen A absorption band

Fig. 2. Schematic of monocular multispectral system with three spectral channels for ranging

Fig. 3. Ideal baseline and spectral intensity curve of target radiation after atmosphere attenuation

Fig. 4. Distributions of (a) sum of error squares and (b) R2 of non-absorbing baseline by linear fitting when N=1

Fig. 5. Deviation distribution of sum of error squares of non-absorbing baseline by different polynomial fittings when N=2. (a) Linear fitting (mean: 83.9008, variance: 0.0889, R2: 0.9998); (b) quadratic polynomial fitting (mean: 82.6881, variance: 8.8413×10-4, R2: 1); (c) cubic polynomial fitting (mean: 82.6742, variance: 1.2449×10-7, R2: 1)

Fig. 6. Non-absorbing baseline by linear fitting and position of different fitting data points

Fig. 7. Difference of absorption coefficients in the oxygen A absorption band

Fig. 8. Variation in (a) absorptivity and (b) slope of absorptivity with path length

Fig. 9. Ideal baseline and spectral intensity curve of target radiation after atmospheric attenuation

Fig. 10. Distribution of sum of error squares of non-absorbing baseline by linear fitting when N=2

Table 1. Sum of error squares between ideal baseline and non-absorbing baselines by different fitting polynomials with different fitting data

Table 2. Absorptivity of oxygen A band with non-absorbing baseline by different fitting polynomials with different fitting data

Table 3. Variance and sum of error squares between non-absorbing baseline and ideal baseline