Fig. 1. Graph of RossThick kernel function changing with illumination observation geometry

Fig. 2. Graph of LiSparseR kernel function changs with illumination observation geometry

Fig. 3. Graph of RossThick Maignan kernel function changing with illumination observation geometry

Fig. 4. Normalized spectral response curves for each spectral segment of HJ-2A CCD. (a) CCD 1; (b) CCD 2; (c) CCD 3; (d) CCD 4

Fig. 5. Normalized spectral response curves for each spectral segment of HJ-2B CCD. (a) CCD 1; (b) CCD 2; (c) CCD 3; (d) CCD 4

Fig. 6. Scatter distributions of measured BRDF data in Dunhuang field. (a) Reflectance distribution at 490 nm; (b) reflectance distribution at 560 nm; (c) reflectance distribution at 660 nm; (d) reflectance distribution at 830 nm

Fig. 7. Scatter distribution of main plane measured BRDF data in Zhaodong (solar zenith angle is 42°). (a) Reflectance distribution at 490 nm; (b) reflectance distribution at 560 nm; (c) reflectance distribution at 660 nm; (d) reflectance distribution at 830 nm

Fig. 8. Flow chart of BRDF correction for wide-field images of Environment-2 Satellite

Fig. 9. Calculation results of image angle for HJ-2B_CCD1. (a) Solar zenith angle; (b) solar azimuth angle; (c) view zenith angle; (d) view azimuth angle

Fig. 10. Schematic diagram of spatial scale matching method

Fig. 11. Comparison of main plane model data fitting results in Dunhuang filed area (solar zenith angle is 50°). (a) 490 nm; (b) 560 nm; (c) 660 nm; (d) 830 nm

Fig. 12. Regression fitting results between simulation values of RTLSR model and RTMLSR model and all data in Dunhuang field area. (a)(e) 490 nm; (b)(f) 560 nm; (c)(g) 660 nm; (d)(h) 830 nm

Fig. 13. Comparison of main plane model data fitting results in Zhaodong area (solar zenith angle is 42°). (a) 490 nm; (b) 560 nm; (c) 660 nm; (d) 830 nm

Fig. 14. Regression fitting results between simulation values of RTLSR model and RTMLSR model and main plane data in Zhaodong area. (a)(e) 490 nm; (b)(f) 560 nm; (c)(g) 660 nm; (d)(h) 830 nm

Fig. 15. Comparison images of HJ-2B satellite multispectral camera before and after BRDF correction. (a) Uncorrected whole scene image; (b) atmospheric corrected whole scene image; (c) BRDF corrected whole scene image; (d) uncorrected partial map of Dunhuang filed area; (e) atmospheric corrected partial map of Dunhuang filed area; (f) BRDF corrected partial map of Dunhuang filed area

Fig. 16. Variation curves of reflectance before and after BRDF correction in each band in Dunhuang field area. (a) HJ-2B_CCD1_20210303; (b) HJ-2A_CCD4_20210126

Fig. 17. Variation curves of reflectance before and after BRDF correction in each band in Zhaodong area. (a) HJ-2A_CCD1_20210901; (b) HJ-2A_CCD2_20210917