Night vision

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

Evaluating New Technologies to Enhance Night Vision by Looking at Detection and Recognition Distances of Non-Motorists and Objects

Abstract: This empirical research aims to identify how new technologies are able to enhance night vision. This research provides empirical data on 12 vision enhancement systems taking into consideration factors such as driver age and type of objects on the roadway (i.e., static and dynamic objects). The results of this study are presented in terms of detection and recognition distances. When the detection distance of different objects were analyzed, the Infrared Thermal Imaging System resulted in the longest detection and recognition distance followed by the halogen low beam headlamps combined with high-output, medium-output, and hybrid ultraviolet headlamps. There was no significant difference, in terms of detection and recognition distances, among the halogen low beam (baseline) and when the ultraviolet headlamps are used. However, there was a significant difference among halogen low beam and high intensity discharge (HID), where halogen allowed drivers to detect and recognize objects at farther distance.

Method and device for visualizing the surroundings of a vehicle

Abstract: A method and device for visualizing the surroundings of a vehicle, in particular for detecting and representing the traffic situation in front of a driver are provided. A night vision information system fuses video images from essentially the same location and time but from different spectral regions are fused using weighting factors. The video images are weighted with a globally settable preliminary weighting factor, and an object analysis of the video images is performed. Based on the object analysis the weighting factors are locally adapted in an object-selective manner.

Evaluation of the impact of multispectral image fusion on human performance in global scene processing

Abstract: : An observer extracts local and global information from a natural scene to form a visual perception. Neisser and Treisman demonstrated that a natural scene contains different types of features, i.e., color, edges, luminance, and orientation to aid visual search. Infrared and visible sensors present nighttime images to an observer to aid target detection. These sensors present the observer an adequate representation of a nighttime scene, but sometimes fail to provide quality features for accurate visual perception. The purpose of this thesis is to investigate whether color features (combining an infrared and visible sensor image) improve visual scene comprehension compared to single band grayscale features during a signal detection task. Twenty three scenes were briefly presented in four different sensor formats (infrared, visible, fused monochrome, and fused color) to measure subjects global visual ability to detect whether a natural scene was right side up or upside down. Subjects are significantly more accurate at detecting scene orientation for an infrared and fused color scene compared to a fused monochrome and visible scene. Both the infrared and fused color sensor formats provide enough essential features to allow an observer to perceptually organize a complex nighttime scene.

Backscatter effects in active night vision systems.

Abstract: A fundamental limitation in using an artificial source of illumination for night viewing is backscatter by the atmosphere. This paper explores that limitation. A mathematical model of an active night vision system is constructed, and formulas for the signal received from a target and the backscatter caused by the intervening atmosphere are derived. Signal-to-noise ratio is defined, and its use as a measure of system performance is discussed. Several hypothetical systems are defined and graphs of the signal-to-noise ratio as a function of range are presented.

Tetradymite layer assisted heteroepitaxial growth and applications

Abstract: A multilayer stack including a substrate, an active layer, and a tetradymite buffer layer positioned between the substrate and the active layer is disclosed. A method for fabricating a multilayer stack including a substrate, a tetradymite buffer layer and an active layer is also disclosed. Use of such stacks may be in photovoltaics, solar cells, light emitting diodes, and night vision arrays, among other applications.