Vehicle-mounted night vision systems have been around for years and are now commonplace, but there are significant changes ahead in this market.
For example, there is a growing demand for higher resolution night cameras. A spokesman for the French infrared receiver company Sofradir said this could be achieved by increasing the number of pixels and decreasing the pixel pitch while maintaining the matrix size in order to ensure low weight and power consumption characteristics of the device.
“By decreasing the pixel pitch, you increase the detector's sensitivity, because as the pixel pitch decreases, each pixel has a lower signal strength, and thus we increase the sensitivity of the device. In current generation cameras, the standard is VGA 640x512, but today the trend is moving towards SVGA 1280x1024 in 12 micron increments, for example. Systems will move in this direction and this is happening now,”
- he explained.
For these cameras to perform at their best, they must be properly stabilized, since armored vehicles operate in rough terrain with very difficult terrain. According to a representative of Controp Precision Technologies, if the system is not stabilized well enough, "then the image will be of unacceptable quality and the range of the device will be drastically reduced."
A Sofradir spokesman said:
“In recent years, we have seen the importance of weight, size and power consumption grow steadily, reflecting the demand for small, lightweight systems with improved capabilities, such as our SIGHT systems. There are several types of cameras: uncooled thermal cameras, which provide close-up vision and are usually not stabilized, and cooled thermal cameras, which are usually stabilized, are of a higher level and of course more expensive."
Highlighting problems
Traditionally, night vision systems have been used for two main purposes. Firstly, the driver's night vision devices allow him to increase the level of control of the environment around the car for safe and trouble-free maneuvering. Secondly, there are sighting systems used by shooters to identify and aim at potential targets.
Infrared systems for drivers and enhanced situational awareness are typically uncooled thermal imaging cameras that have a wider field of view at close range in order to have as much field of view as possible, while scopes are for shooters, especially for large caliber weapons, for example, 120- mm of tank guns, equipped with cooled long-range thermal imaging cameras. The latter have a narrower field of view for focusing on a specific target.
Thermal imaging cameras are the most common in modern armies, as they are more advanced than cameras with image intensification (image intensifier), which operate in steps of less than 1 micron, and to operate they require active emission of light in the near infrared region spectrum in order to see in the dark. At the same time, the light from the infrared illumination invisible to the naked eye can be detected by enemy devices, which can entail serious consequences.
According to Colin Horner of Leonardo, image intensifier cameras are always a problem in communities that tend to be illuminated.
“These sensors tend to distort and blur the image intended for the commander and driver. While image enhancement technology is improving and is the preferred choice for non-combat assisted vehicles, the disadvantage is that such cameras still need backlighting.”
“Although they can really work in minimal lighting, for example, in the light of the moon or stars, in complete darkness, cameras with image intensifier tubes simply will not work. To improve situational awareness, operators use infrared lights to locally illuminate the area around the machine and rely on natural light."
- explained Horner.
He added that there are other problems with image intensifier cameras in cars equipped with bulletproof glass, as they negatively affect the driver's perception of distance. This is why modern armies prefer to use passive infrared systems.
In addition, there is a tendency to increase the night vision capabilities of vehicles of other categories, for which it is necessary to install the same systems on them as on combat platforms. "This will really increase the level of ownership and security."
“As a rule, larger armored combat vehicles were equipped with passive (non-illuminated) infrared systems with very high performance, but they do not work in columns by themselves. They are supported by other vehicles, such as personnel transporters, ambulances and engineering vehicles, but these vehicles have the disadvantage that they do not have the same night vision capabilities as combat vehicles and therefore cannot work in the same conditions. So now we see a trend to equip support vehicles with night vision systems that are not worse than those of combat platforms, as a result of which they can work side by side without additional risk."
Another trend is to add more cameras to machines to get a full all-round view. Previously, the military was only concerned with providing the driver with night vision devices only for driving. With a large number of cameras providing 360 ° visibility, threats can be seen from any direction and, more important for security, there is a view to the sides and back, therefore, the security of the operation in urban areas is increased.
Leonardo offers the DNVS 4 camera, which allows you to get an all-round view at distances of 20-30 meters. Horner said the system is also equipped with a daytime color camera to combine the two technologies in one solution and thus reduce weight, size and power consumption. He added that there is also a shift from analog to digital open architecture. "This means we digitize the camera signal and display it digitally on the screen, which greatly improves image clarity and eliminates any interference from the machine itself."
Picture in numbers
Developments in digital technology allow operators to use multifunctional screens with maps, weapon status and vehicle maintenance information, as well as view multiple images at the same time, such as forward, side and backward views. This is much more versatile than using a dimmed camera or an analog system that allows you to view only one camera and only one display.
Most surveillance cameras are of the uncooled type and, like the human eye, have a wide field of view of about 50 °, and some approach 90 °. Jorgen Lundberg of FLIR Systems said that other cameras must therefore be installed in different configurations to achieve full 360 ° coverage. Some schemes provide for the placement of multiple cameras with a field of view of 55 °, while other schemes provide for the installation of four cameras at 90 ° or even just two cameras at 180 ° to create a panorama. First of all, this is necessary so that the car can freely maneuver without the headlights on during night training and combat operations, since the driver has full control of the environment.
“All of this is aimed at giving drivers or crew the knowledge of what is happening near the car at about 20-100 meters and no further, since the technology today cannot provide high-resolution images at long distances,” Lundberg said. “Although the crew of the car will certainly like to have a high-definition picture of the entire perimeter at their disposal, a balance is needed between today's technology and today's budget. There are also limitations on the number and functionality of crew displays inside the vehicle.”
For example, presenting large amounts of sensory information available is challenging. In order not to mix everything into one pile, crew members, for example, the driver, commander and gunner, must have access to screens that display specific information intended for each of them so as not to interfere with other users. The landing party may also have a screen in the rear of the vehicle, which displays information about the environment before dismounting. The commander can have a screen like other crew members, but with more functionality, for example, with the ability to display decisions on combat control and information on weapons.
Many different sensors are already installed in armored vehicles and night vision systems must find a place for themselves in this limited space. Little space is available in the machine to accommodate more displays and therefore distributing information from sensors and cameras throughout the machine is challenging.
Night vision systems for the main guns of the AFV are located side by side or integrated into the gunner's sight, which is usually installed in the vehicle next to the gun. Armament can be a large-caliber 120-mm tank cannon, medium-caliber cannons (20 mm 30 mm or 40 mm) or even machine guns of 7, 62 mm or 12, 7 mm caliber in a remotely controlled weapons module (DUMV). Gun sighting systems include mainly cooled thermal imaging systems and are therefore capable of operating at ranges over 10 km.
Lundberg said that the gunner's day and night sights are aligned with the axis of the gun, that is, he will look where the gun is directed and not see in other directions.
“The range of this sight should correspond to the range of the gun, and the gun has a rather long range. Therefore, he has a rather narrow field of view, it's like looking through a straw … but here the arrow needs to see and shoot."
Stay cold?
Uncooled infrared cameras use microbolometer technology, which is essentially a small resistor with a silicone element that reacts to heat radiation. Changes in temperature are determined by the intensity of the emission of photons. The microbolometer detects this and converts the measurements into an electrical signal, which in turn can be converted into an image.
Uncooled sensors, as a rule, operate in the LW1R range (7-14 microns), that is, they can “see” through smoke, fog and dust, which is important on the battlefield and in other situations.
Cooled devices use a cryogenic cooling system to keep the detector at -200 ° C, making it more sensitive to even minor temperature changes. Detectors of such devices can accurately transform even a single photon into an electrical signal, while uncooled systems need more photons to make measurements. Thus, cooled sensors have a long range, which improves the process of capturing and neutralizing targets.
But refrigerated systems also have their drawbacks, the design complexity entails high costs and the need for regular and technically complex maintenance. Uncooled sensors are cheaper, easier to maintain, and longer life because they do not use cryogenic technology, have fewer moving parts, and do not require complex vacuum sealing. What type of system to choose, as always, is up to the user, based on the tasks he is solving.
Wave selection
Cooled gunner scopes use near [long wave] infrared (LW1R) detectors. Because this allows night vision systems to see through smoke and therefore have fewer combat-related issues. Uncooled systems also use such detectors, since microbolometers (thermosensitive elements) are sensitive at this wavelength, but this is now beginning to change. “Historically, LWIR has always been preferred because of its better penetration through smoke than MWIR detectors operating in the mid [mid-wave] infrared region,” Horner said.
“Ten years ago that was true, but tests and demonstrations have shown and proven that there is not much difference between LWIR and MWIR on the battlefield today. The sensitivity and capabilities of MWIR have improved significantly over the past 10 years and today MWIR cameras still offer superior performance and smoke penetration. This leads people to prefer MWIR rather than LWIR detectors."
Horner added:
“The advantage of MWIR detectors is that they also have better permeability through humid air compared to LWIR type detectors, that is, when you want to deploy in coastal areas, especially in hot climates, then you will get better performance using MWIR. not LWIR. It will be a compromise solution for the car."
However, a spokesman for the French company Sofradir stressed that the far [shortwave] infrared (SWIR) region of the spectrum also has its application.
“There are two different uses for SWIR. Firstly, detectors of this type can be an additional solution in those cases when you need to look through smoke and dust of different density and origin, and even (in some cases) fog. Depending on atmospheric conditions, SWIR can provide a large apparent distance. Second, with the SWIR detector, you can see laser rangefinders operating at target designation at wavelengths of 1.6 microns or 1.5 microns. It is then used as a warning that your vehicle is under surveillance. You can also see the flashes of cannons, which means SWIR is used to improve situational awareness and protect ground vehicles."
A BAE Systems spokesman said:
“In general, LWIR provides the best performance in all weather and other outdoor conditions, while MWIR and SWIR provide the best contrast. The SWIR image has the added advantage of being similar to what we see with the naked eye. This important advantage increases the likelihood of correct recognition, which in turn helps to reduce the likelihood of incidents with friendly fire."
The need for more
The more frequent installation of DUMV on armored vehicles has an impact on the market for night cameras. The sights of the main cannon are integrated into the platform and therefore neither the weapon nor the sights can change too often. Adding new DUMV on a modular basis allows you to change scopes more often.
In the past five to ten years, the standard weapons installed on the DUMV were in most cases either a 7.62 mm machine gun or a 12.7 mm machine gun, so the sights were, as a rule, uncooled in order to match the short range of these weapons. (1-1, 5 km), and this in turn determined their slightly wider field of view than the sights of large-caliber guns.
However, Lundberg noted that the situation is changing:
“Currently, there is a growing trend that determines the installation of weapons of a larger caliber (about 25-30 mm), from which it is possible to aim and conduct accurate fire at long distances, and this determines the demand for sights for DUMV with a longer range. While the industry used to supply uncooled scopes for 99% of DUMV, today the focus is shifting to more functional uncooled and cooled scopes that can provide ultra-sharp images. This makes it possible to see a little further and direct weapons of a larger caliber to the target at long distances of 1, 5-2, 5 km, that is, beyond the reach of the enemy's means of destruction."
And finally, the commanders want to have even better control of the situation, to see farther than the cannon fires, and therefore there was a need to install night sights with a longer range on the DUMV.
The development of night vision systems is determined not only by the increased range, but also by the need to simplify operations. An outdated thermal imaging camera or less advanced infrared camera requires a lot of work, since you have to press buttons and twist knobs many times to get a decent image, while a new advanced camera can instantly provide a higher quality image for an aiming system with minimal user intervention. A Controp spokesman said: "When most of the elements are automated, the operator can focus on the task itself, and not be distracted by working with the aiming system."
The battlefield advantage of night vision systems is becoming increasingly evident. It does this by taking advantage of the technological advantages of an improved high-resolution camera, using the right type of systems for specific tasks, and integrating more surveillance cameras into a digital architecture that can support more sensors and provide each crew member with the data they need. Individually, these improvements do not bring radical changes, but together they can provide an advantage in battle.
Horner said digital architecture is a long-term solution.
“If you implement digital architecture from the very beginning, then you can have 360-degree control, you can easily integrate future technologies, electronic warfare systems, active protection and long-range surveillance and reconnaissance systems. Then you can safely go ahead and stuff the car with additional advanced technologies."
Lundberg added:
“The proliferation of night vision and thermal imaging systems is proceeding at an unprecedented pace. The military in the West believes that the enemy will only have passive infrared technology. With the rapid development of innovative technologies and export control rules, modern Western armies have a clear advantage. The point, of course, is not in individual thermal imagers and other night vision devices, but in the entire armored vehicle. If you have a scope on DUMV, then the advantage is that you can aim, shoot and accurately hit a few seconds before your opponent. In this sequence of events, night vision systems certainly contribute to the victory over the opponent."
