Hyperspectral imaging collects and processes information from across the electromagnetic spectrum. The goal of hyperspectral imaging is to obtain the spectrum for each pixel in the image of a scene, with the purpose of finding objects, identifying materials, or detecting processes. There are three general types of spectral imagers. There are push broom scanners and the related whisk broom scanners, which read images over time, band sequential scanners, which acquire images of an area at different wavelengths, and snapshot hyperspectral imagers, which uses a staring array to generate an image in an instant.
Two-dimensional projection of a hyperspectral cube
Acquisition techniques for hyperspectral imaging, visualized as sections of the hyperspectral datacube with its two spatial dimensions (x,y) and one spectral dimension (lambda).
Multispectral and hyperspectral differences
Hyperspectral camera embedded on OnyxStar HYDRA-12 UAV from AltiGator
Snapshot hyperspectral imaging
Snapshot hyperspectral imaging is a method for capturing hyperspectral images during a single integration time of a detector array. No scanning is involved with this method, in contrast to push broom and whisk broom scanning techniques. The lack of moving parts means that motion artifacts should be avoided. This instrument typically features detector arrays with a high number of pixels.
Example of a snapshot hyperspectral imaging spectrometer. The scene is viewed through a lenslet array. Each lenslet transmits the light it receives to the fiber to which it is coupled. The bundle of fibers is reformatted and lined up at the entrance slit of a conventional grating spectrometer, which disperses the light across the entrance slit onto its detector.
Data cube acquired by the Very Large Telescope.
