A charged-coupled device (CCD) is a type of electronic detector that is widely used for detection in the visible region. When an ultraviolet coating is added, CCDs are also useful for the UV region. The CCD is made up of an array of rectangular capacitors, called pixels.
In StellarNet products, the standard CCD model has pixels that are 14 x 200 µm. The whole CCD has 2048 pixels in a linear array. When photons hit the pixels, they generate electrons. The electrons are stored in the pixels during the exposure time, then turned into a voltage after exposure. The voltage is turned into a computer-readable digital signal using an A/D converter. The computer reads the signal to generate the final spectrum.
