Fig. 1. Ground light source calibration test^[42]. (a) Test site; (b) working scene

Fig. 2. Integrating sphere light source calibration test^[42]. (a) Physical image; (b) working scene

Fig. 3. DNB detection targets under different moon phase conditions^[19]. (a) Small moon phase angle; (b) large moon phase angle

Fig. 4. Partial low-light image of DNB at 20:14 UTC on October 23, 2018^[42]

Fig. 5. Partial low-light image of DNB at 18:12 UTC on January 27, 2013^[42]

Fig. 6. Partial low-light image of DNB at 17:24 UTC on January 30, 2013^[42]

Fig. 7. Partial low-light image of DNB at 17:39 UTC on May 16, 2017^[42]

Fig. 8. Partial low-light image of DNB at 18:12 UTC on June 2, 2018^[42]

Fig. 9. Partial low-light image of DNB at 19:18 UTC on April 19, 2013^[42]

Fig. 10. Partial low-light image of DNB at 19:20 UTC on May 3, 2014^[42]