Principles of Operation: Notes
The BMW Night Vision camera is a thermal imaging camera, which converts thermal radiation into electronic signals and then into images visible to the human eye.
The thermal image is converted first by the sensor into electrical signals and then with the aid of image-processing software into a visible image in the control display.
The sensor elements alter the resistance in proportion to the temperature. The higher the temperature, the higher the electrical signal and the whiter the pixel will be shown.
Thanks to increased dynamic sensitivity, the sensor can generate a new image up to 60 times per second. This results in a softer and clearer image.
Heat radiation is absorbed and dissipated by virtually every solid or liquid body. Heat radiation, however, is not visible to the human eye because it belongs in the long-wave infrared range. From a physical standpoint, this represents electromagnetic waves with a wavelength of 8 μm to 15 μm. This long-wave infrared radiation is known as Far Infrared (FIR).
The advantage of utilizing radiation in the Far Infrared range is the greater range compared with Near Infrared systems with a wavelength of 0.7 μm to 1.4 μm. These systems require illumination with just this wavelength.
Essentially, FIR systems consist of an optical element, a thermal imaging camera, an control unit and a display.