Sensitivity analysis of carbon dioxide inversion in near-infrared spectra for TanSat-2 satellite

The inherent uncertainties of input parameters in satellite may affect the inversion accuracy of the column-averaged dryair mole fractions of carbon dioxide (XCO₂). Regarding the design specifications of the next-generation carbon satellite (Tansat-2), a sensitivity analysis is conducted on seven input parameters that may affect the XCO₂ inversion. The paper employs the SCIATRAN model to retrieve XCO₂ from short-wave infrared spectra with central the wavelengths at 0.76 μm and 1.61 μm. The results indicate that, considering the uncertainties in measuring these parameters, the parameters influencing XCO₂ inversion are ranked in the following order: the pressure, oxygen, temperature, water vapor, surface elevation, surface albedo, and ozone. To achieve the XCO₂ inversion accuracy within the range of 0.3%-0.5%, it is necessary to ensure the temperature uncertainty of approximately 0.4 K-0.8 K, the pressure uncertainty of approximately 0.2%-0.4%, the water vapor uncertainty of approximately 7%-14%, the oxygen uncertainty of approximately 0.25%- 0.5%, along with the surface albedo uncertainty of approximately 0.2-0.4, and the surface elevation uncertainty of approximately 22.5 m-45 m.