Night Vision: Thermal Imaging To Image Fusion

Night vision systems, once jealously guarded, are now cheaper and more widely available than ever before.

- Stephen W. Miller

The introduction of technology that allows soldiers see in darkness has added a new dimension to the military and civilian agencies operate. As the price of the technology has reduced it has been more broadly adopted to the point that in some armies, night vision of some type can be provided to every front line soldier and tactical vehicle. Some special mission teams in the special forces community and some law enforcement SWAT units have every member equipped with night vision goggles, increasing their tactical advantage over their opponents.

Night Vision Technologies

The first night vision was ‘infrared illumination’ which was an advance over visual ‘white’ lights. A special filter or lens that only allowed the near infrared (IR) spectrum to pass through was placed over a normal visible light source. This could be a flashlight, headlight or searchlight. Near IR cannot be discerned by the human eye but can be with special viewing devices. Requiring a light source though makes it ‘active’ and anyone with an IR viewer can see the source. IR was widely used by armies in the 1950s through the 1970s when it began to be replaced by passive light intensification technology.