Human eyes are powerful electromagnetic wave detectors that react at wavelengths between 400 nm (purple) and 700 nm (red). However, the wave spectrum is much larger and invisible to our eyes.
Today, technology allows us to have special cameras to detect a greater range of frequencies, these are called hyperspectral cameras, and they are capable of obtaining complete information from a band of the spectrum.
Operation: Sensors And Many Colors
To understand how it works, if we inspect the sensor, we will see that the way it operates is very similar to the camera that our cellphone has, but a little more complex (and expensive).
Like common cameras, a hyperspectral camera is composed of an array of sensors that are sensitive to a certain range of the electromagnetic spectrum, generally the range that comprises the Near Infrared or NIR. Then, each pixel reacts differently to the frequencies it receives.
That is, if in a pixel of our cellphone the light is broken down into three RGB levels (Red, Green, and Blue), in the case of hyperspectral, a pixel is represented by hundreds of components each corresponding to a different wavelength in that band of the spectrum.
