In this paper, we demonstrated the best fitting window and spectral resolution to retrieve NO2 Vertical Column Density
(VCD) from space borne spectrometer in ultra-violet. The reflectance at TOA was simulated with atmospheric radiation
transfer model SCIATRAN, which takes both molecules absorption and aerosol multiple scattering into consideration.
The NO2 VCD was retrieved using the Differential Optical Absorption Spectroscopy (DOAS) method. There are five
kinds of factors has been taken into the NO2 VCD retrieval sensitivity analysis: fitting window and spectral resolution,
aerosol optical thickness, surface albedo, NO2 concentration in the lower troposphere and sun-satellite geometry. The
results showed that DOAS method cannot well filter the aerosol scattering. High surface reflectivity can strengthen the
signal at TOA and thus enhance the retrieval accuracy. The AMFs become larger dramatically when the sun or satellite
zenith angels are above 70 degree, while the relative azimuth angel affects little in the AMF.