What is a Hyperspectral Image?

A hyperspectral image is a picture that encompasses the entire light spectrum. These images are typically used to find information that is invisible to the human eye. Certain things, from oil to plant illnesses, show up differently when photographed using non-visible light. This property allows people to locate trace amounts of a substance simply through a photograph, rather than extensive testing. The process of creating a hyperspectral image is expensive, but it is often less expensive than blind testing methods.

Visible light is just a small amount of the light that shines on the earth. These other light bands, such as infrared or ultraviolet, are always present but outside the reach of the human eye. Certain substances look different under these lights, provided a person could see them. These items may glow in strange colors or appear to stand out, almost like a 3D image.

By using a hyperspectral image, people attempt to capitalize on these properties. The original use for this technology was finding oil and minerals. The trace amounts of material in the soil would cause shifts in non-visible light spectrums. After using the images to find likely locations for natural resources, people could go in and make tests in specific areas. This eliminated the need for random or blind testing methods and both sped up the process and reduced its cost.

The technology has since moved into other areas and agriculture in particular has benefited. By using a hyperspectral image, it is possible to monitor things such as soil saturation and composition as well as plant health. Plants absorb different waves of non-visible light based on their overall health; by monitoring this property, a grower may notice a problem long before it is visible on the plant.

A hyperspectral image is made up of many layers of individual images; each of them represents a specific frequency of light. These layers stack on top of one another making a cube-like image showing the entire light spectrum. The strength of a light emission becomes obvious when going through the images since stronger sources push through more frequencies.

This technology is both extremely accurate and easy to use. The only real drawback to a hyperspectral image is the cost of the equipment and information storage. As these areas drop in price, hyperspectral imaging is moving into more and more areas. The technology is already in certain areas of surveillance and high-end construction, but the dropping cost is creating uses in medicine, home security and astronomy.