SWIR or Short-Wave InfraRed imaging covers the wavelength range from 900nm to 1700nm. A large number of applications that are difficult or impossible to perform using visible light are made possible, with great results, using Short-Wave InfraRed (SWIR) imaging, thus enabling the user to “See Beyond the Visible”.
SWIR is similar to visible light in that photons are reflected or absorbed by an object, and provide the strong contrast needed for higher resolution imaging. This is unlike thermal images, which rely on radiated photons.
Sensing in the shortwave infrared has only recently been made practical, due to the development of Indium Gallium Arsenide (InGaAs) sensors. Images from an InGaAs camera are comparable to visible images in resolution and detail however, SWIR images are not in color. This makes objects easily recognizable and yields one of the tactical advantages of the SWIR, namely, object or individual identification.
SWIR Technology Benefits for Surveillance Solutions
Around-the-clock surveillance in all weather conditions is a necessity for many military and emergency services. Often intruders try to disguise their actions using various methods of camouflage that they adapt to the prevailing situation. They exploit atmospheric conditions such as haze, fog, or sandstorms and may even deploy smoke grenades.
The impact of haze and smoke disappears in the short-wave infrared (SWIR). Although image capture in the SWIR misses the color content of the visible realm, SWIR images – which are formed by light reflected by the objects observed – can be interpreted as easily and directly as those in the visible realm.
The following are the major advantages of the SWIR imaging for military applications:
Ability to see images through haze, fog and glass.
High sensitivity and wide dynamic range.
Can be used in conjunction with eyesafe laser and this makes it the ideal detector for Active Imaging.
Low maintenance costs and high MTBF compared to MWIR.
Reading: SWIR Technology