Spectral modelling near the 1.6μm window for satellite based estimation of CO2

Study of satellite retrieved CO2 and CH4 concentration over India

“…The satellite observations rely on the detection of near-IR vibrational overtone -combination bands for concentration retrieval. The region around 1.6 lm is suitable for both CO 2 and CH 4 (Prasad et al, 2014). Understanding global as well as regional variation in concentration of these gases is useful in identifying local sources and sinks, which may in turn be practical inputs for policy management for the GHGs.…”

Radiative transfer modeling of atmospheric methane for satellite measurements in the 1.66 micron spectral window

“…This NIR region around 1.66 mm is fortunately close to the window identified for CO 2 . 39 Analysis of sensitivity of various bands and its variation with resolution point towards 0.2 nm being the optimum limit for resolution in order to get reasonable concentration estimates. The CIBR method is used and a polynomial function obtained for variation of CIBR with concentration.…”

“…In the case of CO 2 , the rotational peaks are $0.7 cm À1 apart and start merging even at high resolutions. 39 In realistic remote sensing observations, other instrumental factors related to dispersion and recording device need to be considered. To apply the CH 4 estimation approach, the final output spectrum with known resolution is essential.…”

“…In the case of CO 2 , the rotational peaks are ∼0.7 cm −1 apart and start merging even at high resolutions. 39…”

“…It is a useful method for retrieval of H 2 O 36–38 and CO 2 concentration. 39 The same procedure can be used in CH 4 concentration retrieval. The CIBR index is the ratio of radiances received by the sensor at peaks of absorbing wavelength ( λ 0 ) with respect to the linear combination of radiances at two neighbouring, non-absorbing wavelengths ( λ 1 and λ 2 ), given as where C1=λ2-λ0λ2-λ1,C2=λ0-λ1λ2-λ1 and L λ is top of the atmosphere radiance at wavelength λ .…”