Construction of a practical hyperspectral image acquisition system

Abstract

Abstract—A hyperspectral image acquisition system has been constructed to collect data in the visible and near-infrared wavelength bands and to support research in imaging spectroscopy. The design solves a number of practical difficulties associated with hyperspectral imaging related to workflow, exposure budget, reflectance calibration and, most importantly, chromatic aberration. Chromatic aberration, present in nearly all nonmonochromatic images, is particularly severe in hyperspectral images and has been significantly reduced by tracking the focal length of the lens as the wavelength changes. Attendant problems such as lens growth during focussing have also been addressed. The system is tightly integrated with software and streamlines an otherwise laborious and potentially error-prone capture process. The system is shown to provide higher quality images (as measured by the modulation transfer function) in an efficient manner with minimal chromatic aberration, simplified workflow and efficient exposure times.