Systematic error estimation and correction in atmospheric CO₂ retrieval

Systematic error is a part of error sources in atmospheric CO2 high precision retrieval, such as the effect of precision deficiency of temperature profile, pressure profile, H2O and atmospheric layers. This error is hard to overcome only using CO2 band, however, it is nearly independent of wavelength of radiation and can be corrected by other bands. Simulations indicate that O2 band can correct CO2 retrieval error largely. GOSAT data observing the Great Xingan Mountains were used to retrieve atmospheric CO2 and the error of CO2 retrieval indeed decreased by O2 correction obviously.