SWIR security camera options
Sensing in the shortwave infrared (SWIR) range (wavelengths from 0.9 to 1.7 microns) has only recently been made practical by the development of Indium Gallium Arsenide (InGaAs) sensors.
Light in the SWIR band is not visible to the human eye. The visible spectrum extends from wavelengths of 0.4 microns (blue, nearly ultraviolet to the eye) to 0.7 microns (deep red). Wavelengths longer than visible wavelengths can only be seen by dedicated sensors, such as InGaAs. Although light in the shortwave infrared region is not visible to the eye, this light interacts with objects in a similar manner as visible wavelengths. That is, SWIR light is reflective light; it bounces off of objects much like visible light. As a result of its reflective nature, SWIR light has shadows and contrast in its imagery. Images from an InGaAs camera are comparable to visible images in resolution and detail; however, SWIR images are not in colour. This makes objects easily recognizable and yields one of the tactical advantages of the SWIR, namely, object or individual identification.
Short wave infrared (SWIR) cameras offer considerable benefits where atmospheric conditions such as rain, fog and mist are common. These conditions typically blind visible cameras. InGaAs SWIR technology is capable of seeing through all but the most severe conditions to provide highly accurate images. SWIR cameras also provide exceptional low light performance, essentially providing high quality images in all but total blackout conditions.
SWIR cameras are available in all of the Silent Sentinel camera platforms and by combining this technology with either video or thermal it will increase the probability of rapid detection, providing low false alarm rates under a range of atmospheric and lighting conditions.
The left side of the image below is visible imagery of a landscape obscured by haze. The right side shows clear SWIR imagery of a targeted spot in the same scene.