Hyperspectral imaging (HSI) is the collection of electromagnetic spectral information over a 2-dimensional or 3-dimensional space. In general, the electromagnetic range that can be exploited by HSI ranges from visible to long wave infrared (LWIR). In HSI large numbers of spectra recorded by multiple charge coupled devices (CCD) are reconstructed into an image depicting the spectral makeup of the probed area.  The data can be evaluated in two ways.  The first is as an image comprised of specific wavelengths of interest.  The second is a reconstructed image based upon interrogation of the spectra dominating each pixel in the original hyperspectral image.  The advantages of HSI include the ability to analyze sample at stand-off distances and over potentially large areas such as battlefields and chemical release plumes. HSI has been applied in the fields of environmental monitoring, geology, mining, agriculture, surveillance, and chemical detection. Instruments are available in a variety of form factors.  Some small handheld devices are available as are larger stationary and vehicle mounted configurations.  The technology is still maturing, but a number of different commercial instruments are on the market.