Fig. 1. DW-DOAS algorithm data processing flow chart

Fig. 2. [in Chinese]

Fig. 3. Fitting results of DW-DOAS and DOAS retrieving NO₂ SCD when select different FWHM on January 1, 2019.(a) 1 nm; (b) 2 nm; (c) 3 nm; (d) 4 nm

Fig. 4. NO₂ absorption cross section (solid line) and selected central wavelength (dashed line) for ground data

Fig. 5. Fitting results of DW-DOAS and DOAS retrieving NO₂ SCD when select different elevation from January 1 to March 31, 2019. (a) 5°; (b) 10°; (c) 20°; (d)30°

Fig. 6. NO₂ absorption cross section (solid line) and selected central wavelength (dashed line) for EMI data

Fig. 7. NO₂ SCD retrieved by DOAS (a) and corresponding by DW-DOAS (b) for one orbit of 6 January 2019, and the relative differences (c) between them

Fig. 8. Fitting results of DW-DOAS and DOAS retrieving NO₂ SCD for one orbit of 6 January 2019

Fig. 9. NO₂ SCD retrieved by DOAS (a) and corresponding by DW-DOAS (b) for all orbits of 6 January 2019, and the relative differences (c) between them