Fig. 1. Spectral response distributions of FY-3D/MERSI-II and simulated TOA spectra of transmittance over clear sky, as well as typical target spectra. (a) Visible band; (b) near infrared band; (c) short-wave infrared band; (d) mid-wave to long-wave infrared band

Fig. 2. Differences of TOA spectral radiance at different sampling frequencies in desert of clear sky. (a) Spectral radiance distribution; (b) absolute difference of spectral radiation; (c) relative difference of spectral radiance

Fig. 3. Radiance relative differences for ten channels at different sampling frequencies in visible bands. (a) CH1 (0.470 μm); (b) CH2 (0.550 μm); (c) CH3 (0.650 μm); (d) CH8 (0.412 μm); (e) CH9 (0.443 μm); (f) CH10 (0.490 μm); (g) CH11 (0.555 μm); (h) CH12 (0.670 μm); (i) CH13 (0.709 μm); (j) CH14 (0.746 μm)

Fig. 4. Radiance relative differences for six channels at different sampling frequencies in near infrared band. (a) CH4 (0.865 μm); (b) CH15 (0.865 μm); (c) CH16 (0.905 μm); (d) CH17 (0.936 μm); (e) CH18 (0.940 μm); (f) CH19 (1.03 μm)

Fig. 5. Radiance relative differences for three channels at different sampling frequencies in short-wave infrared band. (a) CH5 (1.38 μm); (b) CH6 (1.64 μm); (c) CH7 (2.13 μm)

Fig. 6. TOA radiance relative differences for nineteen channels at sampling frequency of 4 nm in reflective solar bands

Fig. 7. Differences of TOA spectral radiance at different sampling frequencies in clear sky of tropic. (a) Spectral radiance distribution; (b) absolute difference of spectral radiance; (c) relative difference of spectral radiance

Fig. 8. Radiance relative differences and absolute differences of brightness temperature for six channels at different sampling frequencies in thermal emissive bands