Recent studies have offered an abundance of evidence which indicates that night blindness is caused by vitamin A deficiency. Both adults and children have been used to investigate the relationship between vitamin A deficiency and night blindness.

The requirement to operate vehicles in low light and/or night environments whilst wearing night vision goggle (NVG) systems has become increasingly common during military operations. There is very limited research investigating injury risks associated with these systems during ground vehicle collisions. This study examined the injury risks associated with wearing the Australian Defence Force - Enhanced Combat Helmet (ECH) and NVG system, in frontal vehicle collisions. This project consisted of two components: (1) crash tests using a sled and (2) numerical simulations of impacts. Four dynamic sled tests were conducted using a 50th percentile, male, Hybrid III dummy positioned on a rigid seat. Frontal impact tests were performed at a 40 km/h change in velocity (*v) and 20 g deceleration. The test configurations were as follows: (a) Base; (no helmet or additional equipment); (b) ECH; and, (c) ECH and NVG. Condition (c) was carried out twice, to determine repeatability. The sled test protocols were reconstructed precisely with the numerical simulation package MADYMO and the simulations were shown to correlate well with the experimental results. Using this validated model, four parametric studies were undertaken to assess the influence of counterweights, seat cushion, seatbelt pre-tensioner, and the vehicle's *v and acceleration on injury risks. The study found that neck loads were within acceptable limits, with the exception of the neck extension moment, which was exceeded for all NVG conditions. Based on the parametric studies, no major improvements were observed in the neck extension moments with the use of counterweights or a seat cushion. In contrast the use of a seatbelt pre-tensioner was observed to decrease greatly this neck injury risk in certain scenarios. The study also identified that a *v of 15 km/h and peak acceleration of up to 14 g were required to keep the neck extension moment below the prescribed injury criteria. However, the high neck extension moment values may have been partially attributable to the stiff Hybrid III neck. This study identified a possible injury mechanism for soldiers using the ECH and NVG system during specific impact scenarios. The method applied in this project was designed to be repeatable.

The requirement to operate vehicles in low light and/or night environments whilst wearing night vision goggle (NVG) systems has become increasingly common during military operations. There is very limited research investigating injury risks associated with these systems during ground vehicle collisions. This study examined the injury risks associated with wearing the Australian Defence Force - Enhanced Combat Helmet (ECH) and NVG system, in frontal vehicle collisions. This project consisted of two components: (1) crash tests using a sled and (2) numerical simulations of impacts. Four dynamic sled tests were conducted using a 50th percentile, male, Hybrid III dummy positioned on a rigid seat. Frontal impact tests were performed at a 40 km/h change in velocity (*v) and 20 g deceleration. The test configurations were as follows: (a) Base; (no helmet or additional equipment); (b) ECH; and, (c) ECH and NVG. Condition (c) was carried out twice, to determine repeatability. The sled test protocols were reconstructed precisely with the numerical simulation package MADYMO and the simulations were shown to correlate well with the experimental results. Using this validated model, four parametric studies were undertaken to assess the influence of counterweights, seat cushion, seatbelt pre-tensioner, and the vehicle's *v and acceleration on injury risks. The study found that neck loads were within acceptable limits, with the exception of the neck extension moment, which was exceeded for all NVG conditions. Based on the parametric studies, no major improvements were observed in the neck extension moments with the use of counterweights or a seat cushion. In contrast the use of a seatbelt pre-tensioner was observed to decrease greatly this neck injury risk in certain scenarios. The study also identified that a *v of 15 km/h and peak acceleration of up to 14 g were required to keep the neck extension moment below the prescribed injury criteria. However, the high neck extension moment values may have been partially attributable to the stiff Hybrid III neck. This study identified a possible injury mechanism for soldiers using the ECH and NVG system during specific impact scenarios. The method applied in this project was designed to be repeatable.

Approved for public release; distribution in unlimited. / Night Vision Devices (NVD) using Image Intensification (II) technology are among the most important sensors used by ground troops and aviators in night operations for modern combat. With the intensified images from these devices, soldiers can see an enemy's movement better and further in darkness. This thesis explores different test methods in evaluating the performances and sensitivities of several NVDs for future image fusion studies. Specification data such as sensitivity, resolution (Modulation Transfer Function) and pixel size are obtained. Comparative analyses of the collected results are made to characterize the performances of the different NVDs. A new method using MATLAB programming to objectively analyze digitized images for characterization of II based NVDs is proposed. This test method can also be extended to the evaluation of Thermal Imaging (TI) systems for comparative analysis with II NVDs. In addition, the feasibility of testing NVDs using both II and TI technologies, with common operating conditions and target boards is discussed. Finally, the potential of using these digitized images for image fusion studies is verified with the test and evaluation results. / Republic of Singapore

QC 351 A7 no. 69 / The history of modern wide -field, high-speed catadioptric lenses is reviewed. One system comprising only spherical curves and representative of the current art for low-light-level systems is evaluated and used as a baseline design in a weight-reduction study. Five aspheric designs are computed and evaluated. It is found that the use of aspherics will permit weight reduction only in certain instances, i.e., if one element of an all-spherical design can be eliminated or if a fundamentally different configuration that is possible only with aspherics is substituted for the all-spherical configuration. Of these possibilities, the elimination of an element is the best replacement for the baseline design. The case of a highly constrained, purely refractive triplet is studied in some detail. Four designs are computed -from the all-spherical case to the most complex polynomial aspheric. It is found that, if only conic aspherics are employed, significant improvement can be obtained and the problems involved are sensibly the same as those in all-spherical designs. When complex aspherics are applied, the problem becomes surprisingly difficult, and there is some indication that a computer can deal with it better than can a human lens designer.

Approved for public release; distribution in unlimited. / Different sensors exploit different regions of the electromagnetic spectrum; therefore, a multi-sensor image fusion system can take full advantage of the complementary capabilities of individual sensors in the suit; to produce information that cannot be obtained by viewing the images separately. In this thesis, a framework for the multiresolution fusion of the night vision devices and thermal infrared imagery is presented. It encompasses a wavelet-based approach that supports both pixel-level and region-based fusion, and aims to maximize scene content by incorporating spectral information from both the source images. In pixel-level fusion, source images are decomposed into different scales, and salient directional features are extracted and selectively fused together by comparing the corresponding wavelet coefficients. To increase the degree of subject relevance in the fusion process, a region-based approach which uses a multiresolution segmentation algorithm to partition the image domain at different scales is proposed. The region's characteristics are then determined and used to guide the fusion process. The experimental results obtained demonstrate the feasibility of the approach. Potential applications of this development include improvements in night piloting (navigation and target discrimination), law enforcement etc. / Civilian, Republic of Singapore

<p>The purpose of this thesis was to determine which perceptual cues drivers use to identify pedestrians that may constitute a risk in traffic. Methods chosen were recordings of pedestrian behaviour in Linköping by means of a stationary video camera as well as video camera mounted in a car. Interviews on the recordings from the mobile camera were conducted with taxi drivers and driving instructors.</p><p>Results include that drivers not only react to pedestrians they believe will behave in a dangerous way, but also react to pedestrians that probably not will behave in such a way, but where the possibility still exists. The study concluded that it was not possible to determine how risky a pedestrian is considered to be by only using behavioural factors such as trajectory or position on the sidewalk, and distance. It is necessary also to include environmental factors, mainly where the pedestrian and car are positioned in relation to the side of the road, so that the behaviour of the pedestrian can be interpreted.</p>

A training unit has been developed that allows NVESD researchers to develop training simulations within virtual environments to enhance infantry skill and awareness. A ground station was developed to house a computer, power system, and video transmission system. This station will allow for a remote operator to wirelessly send a video/audio stream to the handset. The ground station also allows the use of external video and audio inputs to be sent using onboard converters. Different wireless frequencies were evaluated to determine the best for long-range transmission of content. A handset was developed from a carbon fiber prototype shell. The handset features a video receiver, display, power system, OSD system, and external video inputs. The user can view transmitted video and audio while obtaining real-time GPS feedback from the OSD. The alternate video input allows the handset to be used within the virtual environments developed at the University of Kentucky’s Center for Visualization for virtual environments. This thesis will present the research conducted in order to develop Mark VIIE training unit including the requirements for the project, the desired functionality, the NVESD provided equipment, the analysis of the prospective components, the design of custom fabricated parts, and the assembly and integration of the components into a complete system.

This study aims to refine the current cartographic standards and specifications used by the Australian Defence Force to produce the 1:50 000 scale Topographic Line Map (TLM) so that TLMs can be read with both normal chromatic vision and with achromatic NVG vision. The proliferation and integration of Night Vision Goggles (NVG) into the Australian Army has increased the operating capacity of forces at night. The Australian Army has incorporated NVG into standard operating procedures and training to the effect that Australian military personnel do not operate, at night, without NVG. The increased use of NVG in the Australian Army has required existing systems to be modified or redesigned to be effective within the limitations of NVG. The inability to read TLMs effectively with NVG is an identified problem within the Australian Army. This research has investigated the problems associated with using NVG and the information, which cannot be read on TLMs with NVG. This information was compared to a survey of features on a TLM that are critical for successful military operations. The combined information determined which features on a TLM were to be refined to enable effective reading with NVG. The scope of this research limited refinements to current or previous cartographic standards and specifications used by the Australian Army to produce TLMs. Refinements were limited to symbology, size, and colour and three critical information features of contours, watercourses and vegetation. The problems of cartographic design for a dual vision system (chromatic/achromatic) were investigated and it was determined that the common factor of value contrast exhibits the greatest effect on the refinement process. Prototype TLMs were produced and tested with normal and NVG vision to determine the best cartographic portrayal of the critical information features, without compromising the Figure/ground relationship, balance and cognitive meanings of the TLM. A final product was produced from the prototype experiment results providing a TLM for use with both normal and NVG vision. The refined TLM has changed contours from brown to black without changes to symbology or size and watercourses from 0.1mm width to 0.2mm width without changing colour or symbology. Vegetation was retained at the current standard and specification.

Thesis (Ph. D.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.