Example of source derived from the machine learning algorithm (in blue) compared to synthetic spectrum (in black) for order 106. The synthetic spectrum is rescaled with fitted linear contribution of CO₂ (A_CO2) and PH₃ (A_PH3). The correlation coefficient between source and synthetic spectra is noted corr. Above, the source is identified as CO₂ (significant A_CO2 >  0.5 and high corr > 0.3). Below the closest source (highest A_PH3) to the PH₃ synthetic spectrum is not coherent with its presence (A_PH3 <  0.5 and corr < 0.3).