Hyperspectral Theory

A hyperspectral image is one in which the reflectance from each pixel is measured at many narrow, contiguous wavelength intervals. Such an image provides detailed spectral signatures for every pixel. These signatures often provide enough information to identify and quantify the material(s) existing within the pixels. A user could, for instance, employ a hyperspectral image to locate and quantify different types of building materials or minerals that might be present within an area of interest or even within a single pixel.

Airborne hyperspectral surveys are carried out using imaging spectrometers mounted in small twins engine aircraft such as Cessna Titans. Flight lines are planned so that adjacent strips overlap ensuring complete ground cover is achieved. Each strip is composed of successive scan lines acquired by the scanner along the flight line. Hyperspectral surveys therefore capture images from the Earth’s surface in narrow contiguous wavelength partitions or spectral bands, to create a data cube from which diagnostic spectra can be obtained from each pixel in the image.