Optical Sight Research Articles

Invention of Optical Sight in Mobile Radiography with Anti-scatter Grid

In radiography with anti-scatter grid, it is important to make sure that the X-ray beam direct exactly perpendicular to the grid plane. However, it is so difficult to ensure in mobile radiography. An optical sight to ensure X-ray alignment in mobile radiography with anti-scatter grid was devised. The device measures the X-ray beam angle respect to the grid plane by utilizing collimator-lamp. Computed radiography of water phantom on inclined bedding with anti-scatter grid (6 : 1) were done by aid of devised optical sight 20 times. The result showed that the average alignment error of the radiographies by aid of devised optical sight was within 1°, and the maximum error was<2°.

Savremene snajperske puške u opremi Vojske Srbije

The paper describes sniper rifles and optical sights in use in the Serbian Armed Forces. For the purpose of possible design of an optical sight that would meet modern technical and technological standards and needs of the Serbian Armed Forces, the paper analyzes the optical and mechanical characteristics of the aforementioned.

Study on measurement method of zero position’s variation of high-precision optical sight

Study on measurement method of zero position’s variation of high-precision optical sight

高精瞄具重复装卡误差测量

高精瞄具重复装卡误差测量

Study of zero position’s variation for optical sight by using a CCD

Study of zero position’s variation for optical sight by using a CCD

Active laser detection system for recognizing surveillance devices

In recent years, we have seen proliferation in the presence of surveillance devices such as cameras and commercial unmanned aircraft vehicles (UAVs). These devices have posed ever-increasing security threats. This paper proposes an active laser detection system to counter surveillance components by exploiting cat-eye effect. We first establish a cat-eye target detection model and the calculation results show that our proposals are capable of achieving results comparable to those generated by thermal detection systems but more cost effective. We also investigate the properties of reflected spots generated by cat-eye targets, and formulate corresponding recognition criteria. Using our hardware platform and the proposed algorithms, our experiments produce the recognition of static cat-eye targets at a wide range of operating distances, as well as the real-time identification of moving cat-eye targets. These results have not been achieved before, to the best of our knowledge. The entire system can be applied not only for the detection of a wide categories of stationary monitoring targets with cat-eye configurations including cameras and optical sights, but also for tracking and confronting moving surveillance devices such as UAVs.

METHODS FOR INCREASING THE EFFICIENCY OF A DUAL-CHANNEL OPTO-ELECTRONIC SIGHT

The actual task of the aiming equipment manufacturers is to develop autonomous models of optical sights capable of independently measuring and analyzing input parameters in combat conditions and on their basis to make corrections to the guidance system and aiming mechanisms. The aim of the study was to investigate methods for increasing the efficiency of the dual-channel opto-electronic sight of the DNS-1 model for small arms by analyzing the degree of influence of external environmental factors determining the trajectory of a bullet flight and the accuracy of its hit into the target.The variant of the practical implementation of the DNS-1 sight with an integrated ballistic computer, taking into account: wind speed and direction, target location angle, ambient temperature, relative humidity and atmospheric pressure is considered. Evaluation of the rigidity and stability of the sight design was made when fastening it to the receiver along the «swallowtail» guide and on the «Picatinny» bar. In the variant with Picatinny rail, the loads are smaller and distributed more evenly along the line of the body of the sight. Calculations of the trajectory of the bullet from the cartridge 7Н10 with a caliber of 5.45 mm for the AK74Н at distances of 300 and 1000 m were carried out. At a distance of 300 m and at a value exceeding 53.2 cm, the throwing angle remains practically unchanged and lies within 0.2°. For long distances up to 1000 m, the ballistic angle increases to 3°. A method for measuring wind load using a thermal anemometer based on the Dantec Dynamics 55P11 sensor is proposed. Optimization of the anemometer housing design was performed and wind load simulation was performed, wind field velocity distribution was obtained in the aerodynamic blowdown of the anemometer assembly in the range from 2 to 20 m/s. A method is proposed for measuring the angle of the target site using an accelerometer based on the SCA830-D07 sensor with an accuracy of 0.00179°.The presented research results show the possibility of creating a complex automated fire control system for small arms.

Zero Order Correction of Shift-multiplexed Computer Generated Fourier Holograms Recorded in Incoherent Projection Scheme

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Stabilization of the exit pupil in an optical zoom sight with variable magnification

This paper presents and discusses the optical layouts of eyepieces for telescopic systems with variable magnification. It is shown that using optical layouts of eyepieces with a virtual front focus and eyepieces with a telecentric path of the principal rays in object space increases the region of the solutions. Relationships between the parameters of the optical layout of the eyepiece are found that ensure that the position of the exit pupil of the system varies no more than ±5 mm when the nominal relief is 95 mm. Results are presented of the development of the optical systems of zoom sights with a stable position of the exit pupil as the magnification changes.

Research on detection system of optical sights triaxial parallelism

A method for testing triaxial parallelism of optical sights, the triaxial which involve optical sights targeting axis of white & infrared and laser launching axis, is put forward in this paper on the basis of analyzing conventional measuring technique. At first, measuring optical path is improved, and some equipments such as aspherical mirror, high precision CCD camera are employed to eliminate the subjective error; with the analysis of the optical path, the mathematical model of triaxial parallelism is built, and the error factors are analyzed and calculated. Finally the system is calibrated by autocollimation theodolite whose accuracy is 0.5″ and the experimental results show that measurement error is <3″. In a word, the method has great significant engineering value.

Reflection characteristics of shiny optical elements in a broad wavelength region

The reflection characteristics of certain optical elements and sights have been investigated in the 0.3–20-μm wavelength region. It is shown that the reflectance increases in the UV region and depends on the design of the device. Therefore, a promising range for detecting optical devices is the UV region, operation in which makes it possible to achieve high contrast of the image of an object on the background of natural formations. The results of field experiments using laser illumination of optical devices are given.

飞船光学瞄准镜分划板位置误差分析

The optical sight,as a measurement unit for the manned spacecraft,is used to observe the earth.It helps to determine the spacecraft's flight path and flight profile for the astronaut.The optical projector screen reticle plays an important role in the optical sight.Its position accuracy directly affects the determination to the spacecraft profile for the astronaut.The detailed analysis of the position error factors on the optical sight reticle is conducted.The main factor on the reticle position error is determined.The maximum translation amount between the actual position and the ideal location of the reticle is obtained by calculations.

Optical Measurement of Cesium Behavior in a Large H− Ion Source for a Neutral Beam Injector

Optical emission in a negative hydrogen ion source for the Large Helical Device Neutral Beam Injector (LHD-NBI) has been measured to investigate the behavior of Cs. Two optical sight lines exist parallel to the plasma grid, in the discharge area and in the magnetic filter area near the plasma grid. In the discharge area, the spectrum intensity from Cs+ ions is considerably increased during 20 s of the beam extraction. This indicates a considerable increase in the Cs+ density inside the plasma due to the impact of back-streaming H+ ions. A strong neutral Cs spectrum is observed in the magnetic filter area, where the electron density is lower than in the discharge area. The rate of increase of neutral Cs is much enhanced after t = 30 s, probably because the Cs adsorbed on the cooled region inside the arc chamber evaporates because its temperature increases during the long pulse discharge.

EXAMINING DUST GRAIN MODELS USING THE REDDENING AND X-RAY DUST HALO OF TERZAN 2

We use the X-ray dust halo of the low-mass X-ray binary 4U 1724–307, located in the globular cluster Terzan 2, to probe the interstellar medium along this line of sight (LOS). The X-ray dust halo arises from X-rays scattering off of interstellar dust grains. Using a low optical depth sight line to determine the Chandra ACIS point-spread function, we extracted the radial profile as a function of energy and used it to determine the H column density (N H) and cloud location along the LOS for several dust grain models, including the commonly-used models of MRN and WD. The resulting N H values were used to determine the reddening E(B – V), which was then compared with the average E(B – V) for this sight line found by other workers. We found that for this LOS, only the ZDA BARE-AC-S, BARE-GR-FG, and BARE-GR-S models yield reddenings within 1σ of the literature average.

Integrating VISA, IVI and ATEasy to migrate legacy test systems

New software technologies, such as VISA and IVI, continue to bring the industry toward greater standardization. The benefit to the integrator is reduced costs through reuse of the same hardware and software. The benefit to the customer end-user is lower costs by reducing modification and support through the life-cycle to the test station. However, while we position ourselves for the future with PXI and these software technologies, we must still provide support for VXI, GPIB, and instrument drivers that use current software technologies. Using a number of additional tools such as National Instrument's Measurement and Automation Explorer and Geotest's ATEasy, we can have the power of these tools today while waiting for wider acceptance and support of the newer VISA and IVI technologies. We are just now seeing the development of IVI drivers and the ink is still wet on the VISA specification for PXI. ATEasy provided the structure necessary to use these technologies with the current technology. This paper explores the process of implementing and integrating the system driver and instrument drivers for a PXI-based test station for the TOW2 optical sight sensor.

New video-based assistive technologies for low vision

Over the past decade, electro-optical technology has evolved as an important platform for the development of contemporary assistive devices for people with low vision. Video-based devices are now commercially available in iterations corresponding to all commonly differentiated categories of optical low vision aids — hand held, stand mounted, face worn, and head borne magnifiers and telemicroscopes. With several notable exceptions, these developments are manifestations of “technology push” initiatives aimed at replicating the established functionality of conventional CCTV systems within smaller, more portable embodiments by utilizing recent innovations in sensor, display, and lighting technologies. Most of these compact video magnifiers incorporate a variable, but modest, range of magnifications combined with several contrast enhancement selections. Their major weaknesses include over-magnification, mediocre colour rendering, reduced display contrast, narrow viewing angles, aspect ration distortions, non-intuitive camera/display juxtapositions, and modestly limited fields of view. Nonetheless, these devices have been well-received by many low visioned users because they offer several unique advantages over optical magnifiers for some applications. Video devices with distance viewing capabilities are somewhat more ubiquitous. Clinical experience with these multifaceted systems provides greater insight into the full potential of video technology for low vision applications. Their theoretical potential derives from the fundamental posits of contemporary clinical analysis. “Low vision” commonly describes any untreatable condition of diminished vision that interferes with an individual's ability to perform common visual tasks such as reading. Underpinning these functional seeing disabilities is a unique assortment of measurable deficits in tested visual function. These elemental impairments often include visual acuity reductions, contrast sensitivity deficits, glare sensitivity, visual field defects, diminished scotopic or photopic function, and photo-recovery deficiencies. Optical devices invariably produce fixed levels of magnification that provide effective solutions for people with relatively specific impairments performing fairly specific seeing tasks. This approach is somewhat one-dimensional since it invokes a visual acuity solution for all impairment presentations. Video-based technology allows developers to incorporate a much broader range of enhancement options in a single low vision device. These devices produce a video-mediated reality that can be selectively tuned to redress the multifaceted visual deficiencies of most users with respect to most seeing tasks. Our experience with video telescope users reveals the utility of several novel viewing strategies that are exclusive to video device use, including innovative orientation and localization strategies that are potentiated by their zoomable user interface. Another significant performance feature of video devices is their intrinsic capacity to create readily discernable images within a wide range of hostile viewing environments. The increased availability of new video-based low vision devices poses a significant challenge for contemporary vision rehabilitation service providers, who must now resolve their integration into well-established low vision assessment protocols. The growing range and versatility of video devices establishes a viable alternative for most optical sight enhancement systems that is best evaluated using organized assessment protocols that allow assessors and users to directly compare the two intervention options.

A practical millimeter-wave radar calibration target

A simple rectangular-plate millimeter-wave radar calibration target gives RCS values ranging from hundreds to thousands of square meters. This enable tests over extended ranges and with equipment having modest output power. Precise mechanical alignment mechanisms and an optical sight are mandatory, due to the narrow beamwidth. Absorber collars provide an easy way of adjusting the actual RCS according to specific mission requirements, and effectively reduce edge-diffraction effects. The measured V-band calibration uncertainty was less than 0.5 dB, and the pointing resolution was better than 0.05/spl deg/.

Experimental investigation on the mechanical performance of helical ceramic springs

A series of helical ceramic springs were manufactured from MgO partially stabilized zirconia to investigate their mechanical properties. Nine springs were machined from zirconia tubing, initially one inch in length, with a rectangular pitch of 16, 14, or 12 turns per inch. An experimental apparatus that both supports and equalizes the applied loads on springs was developed. The spring deflection versus applied load was measured using an optical sight mounted on a micrometer. Deflection data on each spring were collected, plotted and successfully modeled using Hooke's Law. A more extensive model was used to calculate the shear modulus of rigidity and shear stress. This model incorporates the spring dimensions, pitch, applied load, and deflection and provides insight into the effects of the materials of construction and manufacturing technique on the effective shear modulus of spring. A specific manufacturing effect was observed in the initial deflection resulting from the mass of the spring as the pitch was increased.

Human pupil and eyelid response to intense laser light: implications for protection.

Natural ocular protective measures induced by laser glare at 514 nm were evaluated concomitant with the performance of a tracking task. Light-induced eyelid and pupil responses of 5 volunteers, 1 woman and 4 men, ages 23 to 60 years, were recorded as they tracked a target moving at 0.3 degrees/sec. with an optical sight. Frame-by-frame analysis of video images of the eye allowed assessment of the eyelid response (squint and blink) and measurement of the pupil diameter. Three laser exposure durations (0.1, 1.0, and 3.0 sec.) were used during bright and dim ambient light conditions. All laser exposure trials produced a pupillary constriction with a latency, i.e., the time from the onset of the laser exposure until the pupil began to constrict, of approximately 100 msec. In a representative 3-sec. exposure, the total intraocular energy was reduced by 69% as the pupil diameter decreased from 6.0 to 2.5 mm. For the 0.1-sec. exposures at 1.6 mW/cm2, a blink reflex was observed on 2 of 10 trials under the dim ambient conditions and not observed on 9 trials under bright conditions. For 1- and 3-sec. exposures at 0.33 mW/cm2, a blink reflex was observed on four (3 bright and 1 dim) of the 38 trials. For conditions evaluated, pupillary constriction was consistent and provided some protection when the exposure duration exceeded the pupillary latency period; however, a blink reflex was observed on only a limited number of trials, possibly due to the exposure dose, the small retinal irradiance diameter produced by the laser exposure, and the volunteers' attention to the demanding performance task.

Flight test certification of multipurpose head-up display for general aviation aircraft

Advances in flight display technology have enabled manufacturers to provide a head-up display (HUD) of aircraft control and performance parameters for use in general aviation aircraft without the use of inertial platforms or specialized data bus architecture. The Federal Aviation Administration currently has no regulatory guidance regarding HUD or flight symbology certification. A specific certification pro- gram is presented. The process of categorizing the HUD as a supplemental system instead of a primary display is discussed. Flight display symbology is discussed, and the final symbology set is presented. The certification flight test plan is discussed including the requirements for functional, usability, and opera- tional testing. Flight test data are discussed. A HUD system was certified for single-pilot use in instrument meteorological conditions in a general aviation aircraft. HE head-up-displ ay (HUD) was first developed in mili- tary aircraft from reflecting optical sights. The HUD places flight and navigation data in the pilot's forward field of view (FOV). These data are presented through various symbols as a collimated image that appears to be floating at infinity. Early HUDs were used for weapons delivery with displays tailored for a single task. HUDs today can provide a variety of aircraft state and navigation data. Recent HUD develop- ment, as an enhancement tool to facilitate manually flown in- strument approaches to weather minima as low as a runway visual range of 1200 ft, has obvious implications for air carrier operations. The ability to ease the instrument-to-visual ap- proach transition and acquire the runway environment sooner is a desirable feature of any cockpit display system. Though these systems usually require high-fidelity inertial reference platforms and are costly, the advantage gained in arrival reli- ability has been deemed cost effective. Additionally, because the pilot has state and navigation data available while looking through the aircraft windscreen, the increased ability to visu- ally clear for other traffic is a safety enhancement. Current HUD development and operational concept are toward dis- plays that are useful and certifiable during all phases of flight. Lower cost displays that do not provide enhanced capability, but do provide increased out-of-the-cockpit awareness for cor- porate and general aviation aircraft are also emerging into the marketplace. A typical HUD displays airspeed, altitude, pitch and roll attitude, and heading. In addition, navigation or mission data can usually be selected for display. Flight director modes, radar altitude, and marker beacon passage can also be shown, if available. Most HUDs can also display master warning and caution annunciators. The subject HUD was targeted for the corporate and general aviation industry. This HUD differed from other operational systems in that it used conventional aircraft gyros and did not depend on an inertial navigation system platform for attitude information. Since conventional aircraft gyros are less precise than inertial platforms, the HUD symbology was not confor-