Indirect measurements with a portable computational NIR spectroscopy-the sources of uncertainty and challenges in a multi-use scenario

Reporting on the state-of-the-art of portable NIR spectroscopy, the paper highlights the main sources of uncertainty and challenges limiting the realisation of reliable measurements in a multi-use scenario, e.g. a drift in characteristics of the components constituting the measurement path, spectral instability of the illumination source, environmental noise, etc. Based on computer simulations and laboratory experiments, the variety of possible patterns of measured spectra is demonstrated, implying challenges for quantitative and interpretative analysis in practical applications. A simple experiment with a Planck blackbody model correction showed the potential of reconstructive computational spectroscopy in portable applications, which require further methodological advances, e.g, realization of a forward-inverse modeling approach.