Impact of scene changes during data acquisition in Fourier spectroscopy

Abstract

The impact of changes of the spectral radiance in a Fourier Transform Spectrometer’s field of view (FOV) during recording time of an interferogram is examined. Particularly systematic changes, with a time constant which is in the order of the time required to record one interferogram, are of interest here. Both an analytic and a simulative approach is made to examine the impact on the measured spectrum. Airborne measurements of fire scenes are a typical example where changes of spectral radiance during data acquisition time are inevitable. In such cases, flight velocity causes the scene in the spectrometer´s filed of view to change continuously, and the scene elements (fire, for example) might be expected to be dynamical even by themselves.