A compact and low resolution spectrometer for the inversion of water vapor total column amounts

Observations of atmospheric water vapor (H2O) amounts are required for the investigation of important and current atmospheric studies, such as the hydrological cycle, energy balance, climate change, etc. In this context, we present a portable, very compact, commercial and very low resolution Fourier transform spectrometer for the remote sensing of total column amounts of H2O at a high measurement frequency (one measurement about every 2 minutes). The methodology applied to carry out this work is explained. Moreover, first results are compared with high quality H2O total column amounts obtained by a collocated non-mobile high resolution Fourier transform spectrometer. This inter-comparison documents that the very low resolution instrument is well suited for capturing the variability of H2O total column amounts (with precision better than 4%), but that suffers from a significant wet bias (about 30%).