Night vision technology in automobiles

Night vision technology in automobiles

1. Introduction The word Night vision itself means the ability to see in low light conditions. Humans have poor night vision compared to many other animals. So we all might have a question in our mind that is this really possible to see in the dark night? The answer is most definitely yes. With the proper night-vision equipment, you can see a person standing over 200 yards (183 m) away on a moonless, cloudy night. Originally developed for military use, it has provided the United States with a strategic military advantage, the value of which can be measured in lives. Federal and state agencies now routinely utilize the technology for site security, surveillance as well as search and rescue. Night vision equipment has evolved from bulky optical instruments in lightweight goggles through the advancement of image intensification technology.The night has always had a mysterious and eerie aura to it, due to the darkness that it accompanies. Through time, the dark has always been something that a lot of people fear. As they say, you never know what lurks in the dark. However, as technology developed, the night has become less of a scary monster and even became a sought after period of the day, all thanks to the invention of the night vision. If you're wondering how this innovation started in the first place, read on and learn the history of night vision. It has always been a point that man had to dominate his enemies but at the same time making little damage as he can. In the beginning, men fought at daytime since night raids were considered to be very dangerous. They were and virtually impossible back then. With some time, men realized that surprising their enemies with attacks were much effective and could be very devastating on their enemies' side. This was the situation when torches became a hit, especially in the middle Ages. If a torch can last longer, the better. However, brilliant may torches seem, it gave one big problem- it revealed the position of the attacker. This problem was answered during the 1940's on the midst of World War II, by the innovation of night vision. At first, it was only sniper rifles that had this technology, so that they would have the ability to foresee enemies even from a distance. The use of this gave a dramatic effect on the whole war's course. Ever since the Germans have found its usefulness, they have begun developing innovative technology so that they can successfully dominate even the night. it was during the 1960's Vietnam Era, when military troops began developing night vision technology. It was this time when the night vision goggles first came out and promoted. There was a remarkable advantage seen on those military divisions that has night vision goggles compared to those that did not have them. This became the reason why the government along with the military pushed on with further research about the said technology. In terms of war, the technology was also used in the war against Iraq. It has proved to be an extremely excellent tool, especially for defensive purposes and guarding against the militia. The advantage is also present for thermal vision. Nonetheless, they can get the best of both worlds by combining both thermal and night vision. Doing this gives overwhelming power over the night. Nowadays, night vision technology is widely available even to the public. Most likely, equipments with this feature are used by hunters since it is undeniably a reliable way for them to detect animals even during night time. Two technologies are used for night vision:-(1)Thermal ImagingThis work by collection the tiny amounts of light including the lower portion of infrared light spectrum that are present but may be imperceptible to your eyes, and amplifying it to the point that we can easily observe the image.(2)Image Enhancement This technology operates by capturing the upper portion of the infrared light spectrum, which is emitted as heat by the objects instead of simply reflected as light. Hotter object, such as warm bodies, emit more of this light than cooler objects likes trees or buildings.2. Types of Night VisionThere are two type night visions such as 2.1. Biological Night VisionIn biological night vision, molecules of rhodopsin in the rods of the eye undergo a change in shape as light is absorbed by them. The peak rhodopsin build-up time for optimal night vision in humans is 30 minutes, but most of the adaptation occurs within the first five or ten minutes in the dark. Rhodopsin in the human rods is insensitive to the longer red wavelengths of light, so many people use red light to preserve night vision as it will not deplete the eye's rhodopsin stores in the rods and instead is viewed by the cones..Some animals, such as cats, dogs, and deer, have a structure called tapetum lucidum in the back of the eye that reflects light back towards the retina, increasing the amount of light it captures. In humans, only 10% of the light that enters the eye falls on photosensitive parts of the retina. Their ability to see in low light levels may be similar to what humans see when using first or perhaps second generation image intensifiers2.2. Technical Night VisionA night vision device (NVD) is an optical instrument that allows images to be produced in levels of light approaching total darkness. They are most often used by military and laws enforce agencies but are available to civilian users. In this technology various types of instruments are used. 3. Working of Technical Night VisionNight vision can works in two very different ways depending on the technology used. Before discussing about the types of night vision technology first known basic things of light.3.1. Light BasicsIn order to understand thermal imaging, it is important to understand something about light. The amount of energy in a light wave is related to its wavelength: Shorter wavelengths have higher energy. Of visible light, violet has the most energy, and red has the least. Just next to the visible light spectrum is the infrared spectrum.

Fig.1 Spectrum of lightInfrared light can be split into three categories:-3.1.1. Near-infrared (near-IR)Closest to visible light, near-IR has wavelengths that range from 0.7 to 1.3 microns, or 700 billionths to 1,300 billionths of a meter.3.1.2. Mid-infrared (mid-IR) Mid-IR has wavelengths ranging from 1.3 to 3 microns. Both near-IR and mid-IR are used by a variety of electronic devices, including remote controls.

3.1.3. Thermal-infrared (thermal-IR) Occupying the largest part of the infrared spectrum, thermal-IR has wavelengths ranging from 3 microns to over 30 microns. The key difference between thermal-IR and the other two is that thermal-IR is emitted by an object instead of reflected off it. Infrared light is emitted by an object because of what is happening at the atomic level.Night vision can work in two very different ways, depending on the technology used. 3.2. Thermal ImagingA special lens focuses the infrared light emitted by all of the objects in view. The focused light is scanned by a phased array of infrared-detector elements. The detector elements create a very detailed temperature pattern called a thermo gram. Different from low-light imaging methods of night vision (which require some ambient light in order to produce an image), thermal imaging night vision methods do not require any ambient light at all. They operate on the principal that all objects emit infrared energy as a function of their temperature. In general, the hotter an object is, the more radiation it emits. A thermal imager is a product that collects the infrared radiation from objects in the scene and creates an electronic image. Thermal images are normally black and white in nature, where black objects are cold and white objects are hot. Some thermal cameras show images in color.

Fig.2 The basic of thermal imaging system It only takes about one-thirtieth of a second for the detector array to obtain the temperature information to make the thermo gram. This information is obtained from several thousand points in the field of view of the detector array. The thermo gram created by the detector elements is translated into electric impulses. The impulses are sent to a signal-processing unit, a circuit board with a dedicated chip that translates the information from the elements into data for the display. The signal-processing unit sends the information to the display, where it appears as various colors depending on the intensity of the infrared emission. The combination of all the impulses from all of the elements creates the image.

It is quite easy to see at day time but at night you can see very little Thermal imaging lets you see againFig.3 Different view There are two type of thermal imaging detector3.2.1. Uncooled DetectorThis the most common type of thermal imaging detector. The infrared elements are contained in a unit that operates a room temperature. This type of system is completely quit and activate immediately and the battery built right in.3.2.2. Cooled Infrared DetectorMore expensive and susceptible to damage from rugged used; these system has cooled inside a container that cool them below zero c. These type of system can see more than 1000 ft (300m).3.3. Image IntensifierThis method of night vision amplifies the available light to achieve better vision.Digram is given below. A conventional lens captures the ambient light. This lens focuses available light (photons) on the photocathode of an image intensifier tube.

Fig.4 Image intensifier processThe light energy causes electrons to be released from the cathode which are accelerated by an electric field to increase their speed (energy level). These electrons enter holes in a micro channel plate and bounce off the internal specially-coated walls which generate more electrons as the electrons bounce through. This creates a denser cloud of electrons representing an intensified version of the original image. channel using a process called cascaded secondary emissions electrons pass through the micro- channels, they cause thousands of other electrons to be released in each. Basically, the original electrons collide with the side of the channel, exciting atoms and causing other electrons to be released. These new electrons also collide with other atoms, creating a chain reaction that results in thousands of electrons. The final stage of the image intensifier involves electrons hitting a phosphor screen. The energy of the electrons makes the phosphor glow. The visual light shows the desired view to the user or to an attached photographic camera or video device. A green phosphor is used in these applications.4. Night Vision DeviceNight-vision equipment can be split into three broad categories4.1. ScopesNormally handheld or mounted on a weapon, scopes are monocular (one eye-piece). Since scopes are handheld, not worn like goggles, they are good for when you want to get a better look at a specific object and then return to normal viewing conditions.

Fig.5 scope (monocular)Depending on the model you can obtain higher power lens sets to economically increase the observation range of your scope while others can be upgraded with camera adapters to permit capture of night vision photographs and video. Some scopes can be converted to hands-free mono-goggles or adapted to weapon mounts to serve as night vision rifle scopes, while others are best suited to marine applications thanks to their waterproof construction.4.2. GogglesWhile goggles can be handheld, they are most often worn on the head. Goggles are binocular (two eye-pieces) and may have a single lens or stereo lens, depending on the model. Goggles are excellent for constant viewing, such as moving around in a dark building.

Fig.6 goggles worn on the headMany can be converted to long-range scopes and binoculars and some are even weapon mountable. While all include integrated short-range infrared illuminators that permit map reading and room-to-room searches in complete darkness, long-range illumination requires the addition of one of our infrared sports lights.4.3. CamerasCameras with night-vision technology can send the image to a monitor for display or to a VCR for recording. When night-vision capability is desired in a permanent location, such as on a building or as part of the equipment in a helicopter, cameras are used. Many of the newer camcorders have night vision built right in.5. GenerationsThese are the generations of night vision technology5.1. Generations 0The earliest (1950) night vision products were based on image conversion, rather than intensification. They required a source of invisible infrared light mounted on or near the device to illuminate the target area.5.2. Generations 1In generation 1 three image intensifier tubes connected in series. These systems are larger and heavier than gen2 and gen3. The gen1 clear at the center but may be distorted around the edges. Figure illustrates that first generation night vision. Incoming light is collimated by fiber optics plates before impacting the photocathode which release electron, which is turn impact a phosphor screen. The excited screen emits green light in to a second fiber plate, and the process is repeated. The complete process is repeated three times providing an overall gain of 10,000.

Fig.7 Generations15.3. Generations 2The micro channel plate (MCP) electron multiplier prompted Gen 2development in the 1970s. The "gain" provided by the MCP eliminated the need for back-to-back tubes - thereby improving size and image quality. The MCP enabled development of hand held and helmet mounted goggles. Second-generation image intensification significantly increased gain and resolution by employing a micro channel plate.Figure depicts the basic configuration. These two sentences could have been combined: "Figure2 depicts how second-generation image ... plate." The micro channel plate is composed of several million microscopic hollow glass channels fused into a disk. Each channel, approximately 0.0125 mm in diameter, is coated with a special semiconductor which easily liberates electrons. A single electron entering a channel initiates an avalanche process of secondary emission, under influence of an applied voltage, freeing hundreds of electrons. These electrons, effectively collimated by the channel, increase the resolution of the device. With additional electron optics, details as fine as 0.025 mm can be realized. Current image intensifiers incorporate their predecessor's resolution with additional light amplification. The multialkali photocathode is replaced with a gallium arsenide photocathode; this extends the wavelength sensitivity of the detector into the near infrared. The moon and stars provide light in these wavelengths, which boosts the effectively available light by approximately 30%, bringing the total gain of the system to around 30,000.

Fig.8 Generations25.4. Generation 3Two major advancements characterized development of Gen 3 in the late 1970s and early 1980s: the gallium arsenide photocathode and the ion barrier film on the MCP. The Gas photocathode enabled detection of objects at greater distances under much darker conditions. The ion-barrier film increased the operational life of the tube from 2000 hours (Gen 2) to 10,000 (Gen 3), as demonstrated by actual testing and not extrapolation.5.5. Generation 4Generation 4 is used to describe the most advanced night vision technology. Referred to as 'Filmless & Gated' image intensifiers by the US Military, Generation 4 image tubes provide a notable improvement over Gen 3 night vision. They not only offer increased detection range in pitch-black conditions, but with a dramatically reduced 'halo' they also responded better to bright sources. Whether you are looking for a night vision scope, a hands-free Generation 4 night vision goggles system, or a night vision weapons sight, we can offer a good selection to choose from. We also have Generation 4 night vision binoculars. Fig.9 Percentage of improvement from generation to generation6. ApplicationsThese are the common applications of night vision technology1) Law enforcement-To support law enforcement during the hours of darkness and low light situations and help them detect, deter and prevent the disruption of a enemy. When an event is designated, the Secret Service assumes the role as the lead agency for the design and implementation of the operational security plan. The challenge around events is security on all fronts. During daylight hours and within areas of full light, the playing field is fairly level; however, remove the element of light and someone has the advantage. During events, the challenge is to eliminate low light situations as a potential threat. Prevention, readiness and diligence are the key factors in securing an event from a terrorist threat. Night vision surveillance is a crucial means of protecting an area and its assets before, after and during an event. Night vision techniques give law enforcement the advantage of monitoring activity in darkness and areas of low light. The most effective way to prepare for and provide effective security for an event is to ensure that law enforcement officials have the equipment and training they need long before an event takes place. Therefore with the help of night vision techniques best surveillances can be done in low light conditions.2) Wild life observation- Keen-eyed observer can see much wildlife during the day .but many animals, including most large mammals, are more active at night or twilight. Night-vision binoculars give the option of continuing our observations after the sun has set and the chance to see elusive creatures that are less active during the day. Once a good pair of night-vision binoculars is acquired we can find the best spots to spot critters.3) Security-There are lots of challenges in performing video surveillance at night. The optimal solution for a particular application will depend on the requirements for the specific application. For example, is daytime operation required? Does the system need to be covert what is the size and shape of the area to be monitored? Is the goal of the surveillance to detect, recognize or identify subjects in the field of view? The night vision camera provide best surveillance during night or low light condition and thus prevents the chances of theft, terrorist attack etc4) Military-as the night vision technology was introduced by u s army, its largely used in military operations .it gives the soldiers ability to see during the night with the help of this technology which enables them to fight the enemy troop during night and during the low light environments. Now a days most of the nations have this night vision technology in their defense system. This in turn reduces the rate of deaths during the battle. This technology contributes heavily in the field of military.5) Surveillance- it is used in this field to monitor things or objects or activities of people. This technology in the field of surveillance helps in avoiding and preventing from any mishappenings like illegal activities and other hazardous activities. This technology can be used to monitor certain geographical regions to monitor and study their behavior under different conditions. Various night vision surveillance cameras are available presently. Night vision cameras enable you to protect your valuable assets by capturing video evidence of theft, vandalism and any other unauthorized activity that occurs in low-light conditions where standard security cameras won't work. Today 'nightvision securitycams feature an impressive array of advanced features to make after-hours videosurveillance easy, effective and accurate. Brick House Security offers a comprehensiverange of quality night vision camera systems and accessories to help you keep your office,home or work site safe.6) Navigation-this night vision technology now a day is also used widely in the field of navigation. It is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another. The field of navigation includes four general categories: land navigation, marine navigation, aeronautic navigation, and space navigation. This technology makes the navigation during the night and low light environment easy and quite comfortable.7) Hunting-night vision technology is also used by hunters for hunting animals in the night and low light environments where the human eye visions have some restrictions. This technology has made the hunting in night and low light environment an easy thing for the hunters. Hence this night vision technology gives a great support and help to the hunters while hunting.8) Hidden object detection-night vision technology is also being use to detect the objects during low light conditions.9) Entertainment10) DefenseThe original purpose of night vision was to locate enemy target at night. It is extensively by the military for that purpose, as well as for navigation and targeting. Police and security often use both thermal imaging and image enhancement technology, particularly for surveillance. Hunter is using this to detect the animals and any other birds. Detectives and private investigator use night vision to watch assigned to track. Many businesses have permanently-mounted cameras equipped with night vision to monitor surroundings. A real amazing ability of thermal imaging, is that it reveals whether an has been distributed , it can show that the ground has been dug up to bury something, even if there is no obvious sing to the naked eye. Law enforcement has used this to discover items that have been hidden by the criminal, including money, drugs and bodies. Also recent changes to area such as walls can be seen using thermal imaging, which have provided important clues in several cases. Many people are beginning to discover the unique world that can be found after darkness falls. Night vision technology has various fields of applications. Its application areas in the fields such as military and navigation has an great impact .as days pass by with time there will be even more improvement in this night vision technology and lots of developments are yet to happen in this field.7. ConclusionsThrough night vision device we can see the object in dark environment. We have seen four generation of these devices and seen different ranges. Initially this device was used by military but now it also available for civilians. Today in the 21st century we have come a long way in the development of night vision technology, from the early 1940s. Night vision devices are basically designed for utmost defensive purposes but the application within the scientific or the civilian range is often prohibited by law. In present scenario the applications of night vision technology is very essential to combat terrorism which is a major problem being faced by mankind.Finally we have seen that use of night vision devices. We find that night vision device is used in the presence of ambient light or in case of cloudy weather. There are many types of night vision devices available in the market but in all these devices one things in common: they produced green light. So in overcast and cloudy whether the performance of night vision devices decreased means the detection range is decreased compared to ambient light such as moonlight or starlight.

8. Reference1) Night vision techniques and their applications- Rupesh P.Raghatate, Swapnil S.Rajurkar, Manisha P.Waghmare,Pooja V. Ambatkar(International Journal of Modern Engineering Research (IJMER)) This paper describes the various Night vision techniques."Night Vision" is referenced as technology that provides us with the miracle of vision in total darkness and the improvement of vision in low light environments. This technology is an amalgam of several different methods each having its own advantages and disadvantages. The most common methods described here are Low-Light Imaging, Thermal Imaging and Illuminations. This paper also give brief idea about various night vision device (NVD) that allows images to be produced in levels of light approaching total darkness,it also explains various applications where night vision technology is used to solve various problems due to low light conditions .2) Night vision requirements and possible roadmaps for fir and nir systems- Jan-erik kallhammer,autoliv research se 447 83 vargarda,Sweden3) Review of night vision technologyINVITED PAPERK. CHRZANOWSKI1Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Str., 00908 Warsaw, Poland2Inframet, 24 Graniczna Str., Kwirynow, 05082 Stare Babice, PolandNight vision based on technology of image intensifier tubes is the oldest electrooptical surveillance technology. However, itReceives much less attention from international scientific community than thermal imagers or visible/NIR imagers due to series of reasons. This paper presents a review of a modern night vision technology and can help readers to understand sophisticated situation on the international night vision market.4) An introduction to night vision technology-R Hradayanath (DRDO)5) Night Vision System in BMWAniket S. AhireMechanical Engineering Department, Pune University, INDIAA night vision system must increase visibility in situations where only low beam head lights used today. As pedestrians and animals have highest risk increase in night time traffic due to darkness, the ability of detecting those objects should be the main performance criteria, andthe system must remain effective facing the headlights of the oncoming vehicle. Thus BMW has applied the Night vision system in its vehicles to avoid accidents which can cause the deaths. In the paper, the performance of night vision camera (NVC) is evaluated. The night vision camera is produced by Autoliv for BMW.The paper results not only depended knowledge on performing NVC, but also the understanding the complex product that involves knowledge about engineering involved in it. An Automotive night vision system is system to increase the vehicle drivers perception and seeing distance in darkness or poor weather beyond the reach of vehicles head light. They are currently offered as optional equipment on certain premium vehicles the camera is connected to the front grill of automotive. It senses the images in the form of electronic signal and then sends it via cable to the LCD screen which helps the driver for his convenience. The next generation of automotive night vision system will likely to continue to display to the driver enhanced images of forward drivingscenes.In some display there may also be highlighting of pedestrians and animals, which has-been argued to be the primary safety goal of night vision system

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