IR 1550 for Covert Military Applications|
Article - May 8, 2017 By LarsonElectronics.com
IR 1550 for Covert Military Applications
Infrared (IR) 1550 is a unique, non-visible light beam that has numerous applications in covert military excursions, aerial land surveying (through LIDAR systems) and pharmaceutical manufacturing. This wavelength range is classified in a spectral region that is typically used for long-distance communication. The International Commission on Illumination (CIE) regulates IR 1550 as IR-B, due to its 1550 nm beam measurement.
Some interesting facts surrounding infrared light includes its discovery in 1800 by Sir William Herschel. It is important to consider that most of the energy from the sun arrives on Earth in infrared. This article covers revolutionary IR 1550 military applications that go beyond land-based night vision and enhanced mapping platforms.
SWIR-based Facial Recognition Platforms
The military is using IR 1550 (specifically IR 1150 to 1550) to make facial recognition systems for establishing human identity more effective. By comparison, biometrics-based systems that scan one’s eyes and fingerprints are not suitable for military use, because it requires cooperation from the target individual. Such recognition platforms can be considered intrusive and will likely give away one’s intentions, while drawing unnecessary attention from large crowds. IR-based facial recognition protocols does not require participation from the target individual. Military reps can take IR images from a safe distance during application.
This type of platform is also more advantageous than visible light imaging for establishing human identity. The problem with strict reliance on optimal lighting conditions is its availability. Simply put, most criminals avoid well-lit locations because they are known for ideal spots for surveillance. IR 1550 falls under the shortwave IR (SWIR) range of applications. For imaging, SWIR is able to detect detailed features better than long-wave IR. Moreover, images created using SWIR can be combined with visible light imaging technology for complete facial recognition.
Sponsored by the Office of Naval Research and by the National Science Foundation Center for Identification Technology Research, a team of scientists at West Virginia University (WVU) were able to develop a SWIR-powered facial recognition platform that can match results with visible light images. Impressively, the system can offer 24/7 functionality on the field. When capturing a facial image of the target, the system takes multiple shots at five different wavelengths, ranging between IR 1150 and 1550. During the verification process, the five IR images are compared against a visible light image of the target individual.
The WVU scientists also tested the SWIR facial recognition system on uncooperative targets under low visibility conditions (fog, smoke and nighttime). For clarity in such environments and in order to maintain a standard level of discreetness, the group used IR 1550. Afterwards, photometric normalization (PN) was applied to enhance the IR image before verification.
Long-Range Aerial Attack Detection
Today’s cutting-edge fighter jets travel faster than the speed of sound. When coupled with robust stealth features that supersede the capabilities of radar detection systems, this can become an issue for the target during an attack. During such events, noise from the fighter jet can only be heard after the completion of an attack, preventing individuals in the target area from dispersing or taking cover. Because of this, military engineers have designed SWIR-based anti-air systems that visually detect aerial threats.
The system works by detecting an increase in air temperature from exhaust jets during acceleration, which is greatest before an attack. SWIR imaging is capable of “seeing” the jump in air temperature, when it increases beyond the minimum “visible” temperature threshold of the system. Visually, the exhaust jets look like white spots under the SWIR-based device. This technique also works at night, providing an even greater contrast against the night sky.
Naval/Marine Surveillance (Long-Range SWIR)
During tactical surveillance over large bodies of water, visibility beyond 21 miles is crucial. Devastating weather and low visibility conditions can hinder a naval group’s ability to monitor coastal regions. Furthermore, the use of traditional surveillance equipment is only feasible up to 10 miles in such environments. To improve detection in marine environments, Northern Taiwan by Allied Scientific Pro scientists found that long-range SWIR methods are highly effective.
Since water absorbs SWIR light, water takes on a black color under a SWIR-based camera. This allows military groups to track camouflaged naval vessels (usually painted to blend in with the sea) and boats with stealthy anti-radar features, as far as 12 miles. This practice is also applicable to land-based surveillance operations that are plagued by bad weather.
Military Manufacturing (Inspections)
The machine vision industry is being disrupted by new waves of technologies, i.e., solid-state LEDs and SWIR imaging. The latter is applicable in the same way IR light is used for non-destructive testing (NDT) in manufacturing and other industrial facilities. In military manufacturing, InGaAs (indium gallium arsenide - an alloy of gallium arsenide and indium arsenide) SWIR cameras are replacing thermal cameras due to lower costs, sturdy builds (like LEDs, the units are solid state) and reliable performance.
Machine operators may use such devices to monitor intricate details on the production line. For example, a worker may rely on SWIR technology to ensure a cutter adheres to strict dimensions, while autonomously sensing changes in temperature (to reduce risks related to overheating). In processing superior metals for military tanks, armor and weapons, SWIR-based machine vision protocols may be applied to increase yields. By detecting emissivity differences at a range of 900 nm to 1,700 nm, a specialist can stop the process in a timely manner, before slag contamination. For such uses, SWIR imaging units are protected from heat as high as 3,000 degrees Fahrenheit. Moving forward, military researchers are developing this technology to leverage other wavelength ranges, including 780 nm to 850 nm and 1,800 nm to 2,200 nm.
Outside of military manufacturing, SWIR cameras (with bands between 1,100 nm and 2,200 nm) are being used to streamline large-scale recycling projects by identifying various polymers passing through a conveyer belt. When a camera detects a specific type of polymer, it notifies the conveyer to divert the container to a classified bin for further processing. Lastly, in pharmaceutical manufacturing, SWIR imaging, when combined with hyperspectral spectroscopy systems, may be utilized to analyze liquid chemicals in real-time, as it passes through pipes.