Night Vision Goggles Research Papers (original) (raw)

The study about effectiveness of anti-poaching activities inside and outside wildlife protected areas in Tanzania was carried out in the Tarangire-Lake Manyara Complex; the area defined by water shed boundaries centred on lakes Manyara... more

The study about effectiveness of anti-poaching activities inside and outside wildlife
protected areas in Tanzania was carried out in the Tarangire-Lake Manyara Complex; the
area defined by water shed boundaries centred on lakes Manyara and Burunge and
adjacent lands. The wild animals from Tarangire National Park (TNP) and Lake
Manyara National Park (LMNP) share the same ecosystem. The following parameters
were studied; the type of anti-poaching activities, factors necessitating their use and
administration; their practical applicability, factors hindering effective and efficient
performance and the effectiveness of anti-poaching activities. Four villages in the
complex were included in the study, which include Vilima vitatu, Mwada, Sangaiwe and
Mto wa Mbu. Structured household questionnaire and key informants checklists for
selected community members in the area, TNP and LMNP staff were used for data
collection. The study shows that anti-poaching activities inside and outside wildlife
protected areas are effective in protecting the area natural resources. With poachers arrest
in both TNP and LMNP being higher outside than inside these areas, the Protection
Departments and respondents suggested ways to reduce the incidences of poaching
through effective anti-poaching activities. The study recommends education, provision of
necessary tangible benefits, incentives use, problem animal control and promoting the
cultural tourism to community. The Protection Department staffing, modern facilities and
staff morale should be motivated. Evaluating effectiveness promotes adaptive
management; improves project/programme planning; and promotes accountability.

A concept is described for the detection and location of transient objects, in which a "pixel-binary" CMOS imager is used to give a very high effective frame rate for the imager. The sensitivity to incoming photons is enhanced... more

A concept is described for the detection and location of transient objects, in which a "pixel-binary" CMOS imager is used to give a very high effective frame rate for the imager. The sensitivity to incoming photons is enhanced by the use of an image intensifier in front of the imager. For faint signals and a high enough frame rate, a

If night vision goggles (NVGs) are to be safely used by pilots, it is necessary that the cockpit lighting and displays be compatible with the operation of the NVGs. The current standard field practice for verifying that cockpit lighting... more

If night vision goggles (NVGs) are to be safely used by pilots, it is necessary that the cockpit lighting and displays be compatible with the operation of the NVGs. The current standard field practice for verifying that cockpit lighting and displays are compatible with the NVGs is to conduct a visual acuity degradation assessment. This method is subjective and, as the research described herein, relatively imprecise. An alternative method is to directly measure the amount of interfering light caused by the cockpit lighting and displays. This is referred to as the NVG light output method or NLO. The research reported here demonstrates the superiority of the NLO method compared to the visual acuity method with respect to objectivity and precision. Although the NLO method still needs some further refinement, it is recommended that this method be adopted as a standard field method for assessing cockpit lighting compatibility.

Anecdotal evidence suggested that bright, night-vision imaging system (NVIS) compatible, green cockpit displays could cause a veiling luminance in night-vision goggles (NVGs) and degrade visual performance. The mechanism suspected of... more

Anecdotal evidence suggested that bright, night-vision imaging system (NVIS) compatible, green cockpit displays could cause a veiling luminance in night-vision goggles (NVGs) and degrade visual performance. The mechanism suspected of causing this veiling luminance was an infrared emission from the image intensifier tube photocathode stimulated by visible, NVIS compatible light. This paper describes an effort to measure this stimulated infrared emission from three different image intensifier tubes. Measurements of the emission were analyzed with respect to tube age, the wavelength of incident illumination, and illumination angle of incidence. The emission was found during certain combinations of light wavelengths, angles, and intensities. However, results suggest that this phenomenon is not sufficiently strong to cause observable veiling luminance in NVGs.

The current paper defines a new mathematical model of night vision devices choice taking into account the external surveillance conditions. The night vision device working range is an important NVD parameter influenced by the external... more

The current paper defines a new mathematical model of night vision devices choice taking into account the external surveillance conditions. The night vision device working range is an important NVD parameter influenced by the external surveillance conditions. The developed mathematical model is used to formulate multicriteria combinatorial optimization tasks which solutions provide night vision devices choice based on preliminary theoretical estimation of the device working range under expected external surveillance conditions. Additional user requirement about the preferred working range value is used as restriction in optimization tasks. The practical applicability of the proposed night vision devices choice approach is proved by numerical examples based on real night vision goggles and external surveillance conditions data. The multicriteria combinatorial mixed integer optimization tasks are solved by weighted sum method using the software system LINGO v. 11. The proposed approac...

Image intensifier tubes, as part of night vision devices, have been the primary devices for the detection and amplification of near infrared light for night vision operations. In this paper, we demonstrate a novel all-optical night vision... more

Image intensifier tubes, as part of night vision devices, have been the primary devices for the detection and amplification of near infrared light for night vision operations. In this paper, we demonstrate a novel all-optical night vision amplifier device with a potential to replace the image intensifier tube in night vision goggles. This image amplifier is based on a novel structure of semiconductor and spectrally tunable liquid crystal (LC) materials within a thin cell. The LC reacts to near-infrared (NIR) radiation but is unaffected by visible light, allowing see-through capability including visible-wavelength cockpit light. The technology is made very attractive by its high sensitivity, spatial resolution, and contrast without expensive, bulky, and heavy optics or high-voltage components.

Expected temporal effects in a night vision goggle (NVG) include the fluorescence time constant, charge depletion at high signal levels, the response time of the automatic gain control (AGC) and other internal modulations in the NVG.... more

Expected temporal effects in a night vision goggle (NVG) include the fluorescence time constant, charge depletion at high signal levels, the response time of the automatic gain control (AGC) and other internal modulations in the NVG. There is also the possibility of physical damage or other non-reversible effects in response to large transient signals. To study the temporal behaviour of an NVG, a parametric Matlab model has been created. Of particular interest in the present work was the variation of NVG gain, induced by its automatic gain control (AGC), after a short, intense pulse of light. To verify the model, the reduction of gain after a strong pulse was investigated experimentally using a simple technique. Preliminary laboratory measurements were performed using this technique. The experimental methodology is described, along with preliminary validation data.

Night vision devices (NVDs) or night-vision goggles (NVGs) based on image intensifiers improve nighttime visibility and extend night operations for military and increasingly civil aviation. However, NVG imagery is not equivalent to... more

Night vision devices (NVDs) or night-vision goggles (NVGs) based on image intensifiers improve nighttime visibility and extend night operations for military and increasingly civil aviation. However, NVG imagery is not equivalent to daytime vision and impaired depth and motion perception has been noted. One potential cause of impaired perceptions of space and environmental layout is NVG halo, where bright light

We propose a knowledge-based public health situation awareness system. The basis for this system is an explicit representation of public health situation awareness concepts and their interrelationships. This representation is based upon... more

We propose a knowledge-based public health situation awareness system. The basis for this system is an explicit representation of public health situation awareness concepts and their interrelationships. This representation is based upon the users" (public health decision makers) cognitive model of the world, and optimized towards the efficacy of performance and relevance to the public health situation awareness processes and tasks. In our approach, explicit domain knowledge is the foundation for interpretation of public health data, as apposed to conventional systems where the statistical methods are the essence of the processes. Objectives: To develop a prototype knowledge-based system for public health situation awareness and to demonstrate the utility of knowledge intensive approaches in integration of heterogeneous information, eliminating the effects of incomplete and poor quality surveillance data, uncertainty in syndrome and aberration detection and visualization of comp...

Close Target Reconnaissance (CTR) patrols can be characterized by activities that involve naturalistic decision making to develop situation awareness through processes of sense-making. Any technology that is introduced into such activity... more

Close Target Reconnaissance (CTR) patrols can be characterized by activities that involve naturalistic decision making to develop situation awareness through processes of sense-making. Any technology that is introduced into such activity needs to be sufficiently “invisible” so as not to disrupt or otherwise interfere with the activities of search and interpretation. It is proposed that some technologies, such as imaging devices, can support recognition-primed decision making (RPDM). It is suggested that providing CTR patrols with cameras could supplement existing technologies, such as night vision goggles or binoculars, and provide an opportunity to capture useful intelligence. The concept of location-based photography (in which metadata are collected in parallel with images) provides a means of effectively producing patrol reports in real time. A prototype system is described and trialled comparing conventional practices surrounding note-taking and report writing with the use of location-based photography. The results show little difference in time spent patrolling under the two conditions but significant improvement in reporting under the location-based photography condition. One explanation of these differences relate to the manner in which note taking provides support for sense-making but could interfere with RPDM (through the need to analyze the situation in sufficient detail to make notes), whereas imaging can be performed as part of the RPDM activity. Tagged images change the nature in which the reports are written in that sense-making is performed largely post hoc, which allows flexibility in interpretation and analysis.

Liquid crystal modulated optical amplifier for night vision imaging. [Proceedings of SPIE 7050, 70500U (2008)]. Alexander Parfenov, X. Winston Xia, Indra Tengara, Tin Win, Jason Holmstedt, Neven Rakuljic, Tin M. Aye, Mathew W. Swinney,... more

Liquid crystal modulated optical amplifier for night vision imaging. [Proceedings of SPIE 7050, 70500U (2008)]. Alexander Parfenov, X. Winston Xia, Indra Tengara, Tin Win, Jason Holmstedt, Neven Rakuljic, Tin M. Aye, Mathew W. Swinney, Peter L. Marasco. Abstract. ...

Increased helmet-mounted mass and specific neck postures have been found to be a cause of increased muscular activity and stress. However, pilots who use night vision goggles (NVG) frequently use counterweight (CW) equipment such as a... more

Increased helmet-mounted mass and specific neck postures have been found to be a cause of increased muscular activity and stress. However, pilots who use night vision goggles (NVG) frequently use counterweight (CW) equipment such as a lead mass that is attached to the back of the flight helmet to provide balance to counter the weight of the NVG equipment mounted to the front of the flight helmet. It is proposed that this alleviates this stress. However, no study has yet investigated the physiological effects of CW during an extended period of time during which the pilots performed normal operational tasks. Thirty-one Canadian Forces pilots were monitored on consecutive days during a day and a NVG mission in a CH-146 flight simulator. Near infrared spectroscopy probes were attached bilaterally to the trapezius muscles and hemodynamics, i.e., total oxygenation index, total hemoglobin, oxyhemoglobin, and deoxyhemoglobin, were monitored for the duration of the mission. Pilots either wor...

To evaluate visual performance and resolution through night vision goggles (NVG) before and after photorefractive keratectomy (PRK). Nonrandomized, comparative (self-controlled) trial. Nineteen patients (38 eyes) of active-duty US Army... more

To evaluate visual performance and resolution through night vision goggles (NVG) before and after photorefractive keratectomy (PRK). Nonrandomized, comparative (self-controlled) trial. Nineteen patients (38 eyes) of active-duty US Army Special Forces soldiers. PRK for myopia and astigmatism. Visual acuity with best optical correction was measured preoperatively and postoperatively (3 months) using acuity charts of various contrast (100%, 10%, 2.5%, 1.25%). Preoperative and postoperative (3 month) uncorrected and best-corrected visual resolutions through NVGs were assessed using a high contrast tribar chart presented at four light levels (3.44 x 10(-3), 1.08 x 10(-3), 1.04 x 10(-4), 1.09 x 10(-5) foot Lamberts) simulating a range of night sky conditions. Subjects were trained before testing. Uncorrected visual acuity at the 3-month postoperative assessment was greater than or equal to 20/20 in 33 of 38 (86.8%) eyes. No eyes lost 2 or more lines of best spectacle-corrected visual acuity. Preoperative and 3-month postoperative best-corrected low-contrast acuity measurements showed no significant differences at all levels of resolution. Preoperative visual resolution through NVGs decreased systematically with decreasing night sky condition. Visual acuities before PRK were reduced without optical correction. Postoperative visual performance with NVGs (without optical correction) equaled or exceeded performance preoperatively with best correction. This prospective case series provides data on the safety and efficacy of PRK with respect to visual performance under night sky conditions using NVGs. There was no significant loss of visual acuity across a range of contrast levels 3 months postoperatively. There was no change in best-corrected NVG visual resolution postoperatively, whereas uncorrected visual resolution was significantly enhanced compared with preoperative levels. This improvement may translate into better function for soldiers who are unable to or choose not to use optical correction in operational environments.