Night vision

About: Night vision is a research topic. Over the lifetime, 6004 publications have been published within this topic receiving 67372 citations.

Visible/near infrared image sensor array

Abstract: A MOS or CMOS sensor for high performance imaging in broad spectral ranges including portions of the infrared spectral band. These broad spectral ranges may also include portions or all of the visible spectrum, therefore the sensor has both daylight and night vision capabilities. The sensor includes a continuous multi-layer photodiode structure on a many pixel MOS or CMOS readout array where the photodiode structure is chosen to include responses in the near infrared spectral ranges. A preferred embodiment incorporates a microcrystalline copper indium diselenide/cadmium sulfide photodiode structure on a CMOS readout array. An alternate preferred embodiment incorporates a microcrystalline silicon germanium photodiode structure on a CMOS readout array. Each of these embodiments provides night vision with image performance that greatly surpasses the GEN III night vision technology in terms of enhanced sensitivity, pixel size and pixel count. Further advantages of the invention include low electrical bias voltages, low power consumption, compact packaging, and radiation hardness. In special preferred embodiments CMOS stitching technology is used to provide multi-million pixel focal plane array sensors. One embodiments of the invention made without stitching is a two-million pixel sensor. Other preferred embodiments available using stitching techniques include sensors with 250 million (or more) pixels fabricated on a single wafer. A particular application of these very high pixel count sensors is as a focal plane array for a rapid beam steering telescope in a low earth orbit satellite useful for tracking over a 1500-meter wide track with a resolution of 0.3 meter.

Modern night vision goggles for advanced infantry applications

Abstract: Northrop Grumman Electro-Optical Systems (NGEOS) has concentrated in recent years on the development ofadvanced night vision goggle (NVG) systems. These NVGs developments concentrate on past operational deficienciessuch as high light/bright source imaging during military operations in urban terrain (MOUT), poor individual movementtechnique (IMT) infantry operations, and obscured viewing in battlefield and reduced weather conditions. The first areaof NVG advancement involves direct image intensifier (I 2 ) replacement involving automatic gated power supplytechnology for wide dynamic range NVG operation and advanced Generation III halo free I 2 technology for reduction ofNVG image halo and “blooming” artifacts. The second significant development area is NVG individual movementtechnique (IMT) deficiencies such as reduced field of view, reduced depth perception, center of gravity problems, andlimited operation flexibility. These issues of NVG IMT have resulted in the development of an enhanced IMT nightvision goggle for the U.S. Army known as the enhanced night vision goggle (ENVG). Finally, Northrop Grumman EOSis developing a NVG with the capability of producing optimized real-time image fusion from an image intensifiedsensor and uncooled long wavelength infrared (LWIR) sensor. This new technology allows for optimum imaging inbattlefield obscured and laser polluted environment. These image fusion NVG development activities have concentratedon both optical overlay image fusion and digital image fusion. This paper will compare and contrast these two types ofimage fusion technologies.Keywords: Night Vision Goggle, Night Vision System, Image Intensifier, Thermal Infrared Imager, Image Fusion

Color night vision for navigation and surveillance

Abstract: Fusion of registered images of night scenery that are obtained from cameras tuned to different bandwidths will be a significant component of future night-vision devices. A new algorithm for such multispectral image fusion is described. The algorithm performs gray-scale image fusion using a method based on principal components. The monochrome fused image is then colored by means of a suitable pseudocoloring technique to produce the fused color output image. The approach can easily be used for any number of bandwidths. Examples illustrate the algorithm's use to fuse an intensified low-light visible image with another image obtained from a single forward-looking infrared camera. The algorithm may be implemented readily in hardware for use in night-vision devices as an important aid to surveillance and navigation in total darkness. The applicability of the technology to transportation is also discussed.

Quantitative evaluation of night vision and correlation of refractive and topographical parameters with glare after orthokeratology

Abstract: To evaluate night vision disturbance and investigate correlations between pre- and post-treatment parameters and glare scores in orthokeratology patients. Twenty-eight right eyes of 28 patients were enrolled in this study. Corneal topography and a night vision test (NVT) to evaluate the extent of glare were performed after orthokeratology. From the corneal topography, two indices [surface regularity index (SRI) and surface asymmetry index (SAI)] were calculated. Fourier analysis was performed on the topographic data from the central 6 mm, and data were decomposed into asymmetric and higher order components for analysis. There was no correlation between the glare score and pre-treatment keratometric value, pre-treatment cylinder, post-treatment sphere, and post-treatment cylinder. However, there was a statistically significant correlation between pre-treatment sphere and glare score (Pearson correlation coefficient, r = −0.54, p < 0.01). SRI and SAI significantly correlated with glare score (SRI: r = 0.52, p < 0.01, SAI: r = 0.41, p < 0.05). Higher order and asymmetric components were also significantly correlated with glare score (asymmetry: r = 0.61, p < 0.01, higher order: r = 0.67, p < 0.001). The glare score was significantly correlated with corneal irregularity, and appeared to be a beneficial parameter for assessment of night vision performance in patients receiving orthokeratology.