PowerPoint Presentation: NIGHT VISION TECHNOLOGY Presented by G.KANAKA DURGA CONTENTS: Introduction Generations Working of NVT Night vision devices How to choose a right NV device Advantages Applications Future scope CONTENTS INTRODUCTION: Night vision technology, literally allows one to see in the dark .It is originally developed for military use. With the proper night-vision equipment, we can see a person standing over 200 yards (183 m) away on a moonless, cloudy night. INTRODUCTION PowerPoint Presentation: Human vision is confined to a small portion of the electromagnetic spectrum called visible light. Inorder to achieve NV, beyond the visible light spectrum has to be used. (such as near-infrared or ultraviolet radiation). PERFORMANCE ATTRIBUTES: There are three important attributes for judging NVD performance. They are: Sensitivity - ability to detect available light Signal-to-noise ratio Resolution - This is the ability to resolve the details in the image. PERFORMANCE ATTRIBUTES GENERATIONS: GENERATIONS Generation 0 (1940’s and 1950’s): This generation devices mostly depends on an external infrared light source to produce an image. These images were fuzzy and distorted. Generation 1 (1960’s): G-1devices use improved electronics to produce an image without the need for an external light source. drop-off in quality around edges of image. PowerPoint Presentation: Generation 2 (1980’s): offers good performance in low-level light. very little distortion. well suited for use with cameras. Light amplification for Generation 2 devices is typically 30,000 times. Generation 3 (1990’s): excellent low-level light performance. virtually no distortion. Light amplification for Generation 3 devices is typically 50,000 times. WORKING OF NVT: Night vision can work in two very different ways, depending on the technology used. 1.Image enhancement and 2.Thermal imaging. IMAGE ENHANCEMENT: It uses the lower portions of IR light spectrum. THERMAL IMAGING: It uses the higher portions of IR light spectrum. WORKING OF NVT IMAGE ENHANCEMENT: IMAGE ENHANCEMENT Fig: The image-intensifier tube changes photons to electrons and back again. PowerPoint Presentation: A conventional lens, called the objective lens, captures ambient light. The image-intensifier tube has a photocathode , which is used to convert the photons of light energy into electrons. The original number of electrons are multiplied by a factor of thousands through the use of a Micro Channel Plate (MCP) in the tube. At the end of the image-intensifier tube, the electrons hit a screen coated with phosphors. The energy of the electrons causes the phosphors to reach an excited state and release photons. These phosphors create the green image on the screen. THERMAL IMAGING: THERMAL IMAGING Fig: The basic components of a thermal-imaging system PowerPoint Presentation: A 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 thermogram. The thermogram 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. PowerPoint Presentation: It’s quite easy to see everything during the day... ...but at night, you can see very little. Thermal imaging lets you see again. NIGHT VISION DEVICES: Scopes: Goggles: Normally handheld or mounted on a weapon. Scopes are monocular (one eye-piece). While goggles can be handheld, they are most often worn on the head. Goggles are binocular (two eye-pieces). NIGHT VISION DEVICES PowerPoint Presentation: Cameras: Cameras with night-vision technology can send the image to a monitor for display or to a VCR for recording. HOW TO CHOOSE A RIGHT NV DEVICE: HOW TO CHOOSE A RIGHT NV DEVICE Night vision camera - 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 . Monocular – to survey a larger area. Night vision goggles - objects at a distance into a clearer focus at night for both eyes. ADVANCED NVT: ADVANCED NVT Night vision contact lenses allow a person to see clearly in low- light environments by enhancing ambient light up to 200 per cent. PowerPoint Presentation: BMW has added a night vision feature to the optional gadgets list for their new 7-series sedans. ADVANTAGES: ADVANTAGES Night vision devices are compact in size. Easily portable. It is widely used in military purposes. Working is very simple. Easy to use. APPLICATIONS: APPLICATIONS Military Hunting Wildlife observation Security Navigation Hidden-object detection FUTURE SCOPE: The Army is pushing night-vision technologies into the digital realm (ENVG-D) . i.e.., Future night-vision goggles are being designed not just to see better at night but also to allow soldiers to share images of what they see with other soldiers who may be miles away. FUTURE SCOPE PowerPoint Presentation: Queries ?