Imaging static Fourier transform spectrometry: impact of trajectory perturbations on the hyperspectral images

Imaging static Fourier transform spectrometry (isFTS) may be used for pushbroom air- or spaceborne hyperspectral remote sensing. In isFTS, the spectral information is multiplexed over several instantaneous images, and numerical reconstruction is needed to recover the full spectrum for each pixel. The registration of instantaneous images is a crucial step. Unsufficient precision leads to artefacts on the images and degradation of the estimated spectra. We developed a simulation program of the entire processing chain of an isFTS system that can reproduce the degradations of actual isFTS images. Using this program we studied spatial and spectral effects of temporally correlated and uncorrelated trajectory perturbations. We also performed a theoretical study to quantify these degradations. We demonstrated that the most significant degradations occur in the regions of high radiance gradient.