WHAT IS HYPERSPECTRAL IMAGING?

WHAT IS HYPERSPECTRAL IMAGING? – VIDEO MANUSCRIPT:

A good way to work with materials, identify them, or define their properties is to study how light interacts with them. This study of light interaction with materials is called spectroscopy. Spectroscopy examines how light behaves in the target and recognizes materials based on their different spectral signatures.

These spectral signatures can be identified from the spectrum of the material. Spectrum describes the amount of light at different wavelengths. It shows how much the target emits, reflects, or transmits light. In short, the spectrum tells how much of specific color this light contains.

What is hyperspectral imaging

The usual way to present a spectrum is a graph on a scale of intensity and wavelength.

Spectrum

IDENTIFY DIFFERENT MATERIALS BASED ON THEIR SPECTRAL SIGNATURES

Spectral signatures can be compared to fingerprints. Since every material and compound reacts with light differently, their spectral signatures are different too. Just like fingerprints can be used to identify a person, spectral signatures can locate the material.

Spectral signature

Let’s examine the reflected light in more detail. To study the light, one needs an instrument called a spectrometer. It’s an instrument that splits the incoming light into a spectrum. In this example, the light going through a spectrometer is reflected, and the result is called a reflectance spectrum. Measuring the reflectance spectra is the most common way to use hyperspectral imaging.

Reflectance spectrum

HYPERSPECTRAL IMAGING GIVES THREE-DIMENSIONAL INFORMATION ABOUT THE TARGET

Hyperspectral imaging uses an imaging spectrometer to collect spectral information. This device is also called a hyperspectral camera. We measure thousands or hundreds of thousands of spectra with a hyperspectral camera, instead of a single spectrum.

Hyperspectral camera

The collected spectra form an image of the target so that each image pixel includes a complete spectrum. By doing this, we can get answers to questions on what, based on the spectrum and where based on the location. We can pick any position from the target to get the information. This means a large amount of accurate information. Hyperspectral imaging data is called a data cube because the hyperspectral information is three dimensional.

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