Information and Metrology-Driven Optimisation of Wavefront Error in Telescope-Detected Radiation

2020 ◽  
pp. 37-51
Author(s):  
V.V. Sychev ◽  
A.I. Klem
Keyword(s):  
Wave Front ◽  
Uniform Distribution ◽  
Optical System ◽  
Software Package ◽  
Spherical Aberration ◽  
Space Telescope ◽  
Exit Pupil ◽  
Wavefront Error

The paper presents a solution to an information and metrology problem concerning minimising the wave-front error of telescope-detected radiation. As an example, we used aberration computation and simulation describing the optical system of the space telescope installed in the Millimetron observatory. We show that many factors that affect a space telescope decrease the quality of the image obtained. It is necessary to eliminate the effects of the distortion-generating factors and reduce their contribution to the total wavefront error. As the dimensions of the collecting aperture in telescopes increase, the factors that distort the wavefront of the radiation detected by the telescope begin to significantly affect the quality of the image obtained. We consider the ways of decreasing the effects of the distortion-generating factors caused by aberrations in the optical system. One of the solutions to this problem is to select a rational configuration of the space telescope optical system. In order to minimise the aberration, we used the Zemax 13 Release 2 SP4 Premium software package to simulate the optical system, to analyse and optimise it so as to diminish the scattering spot in the exit pupil. We achieved this goal by decreasing the spherical aberration and ensuring a more uniform distribution of it over the field. We used the data obtained to estimate the admissible dimensions of the misalignment spot

scholarly journals Current Status of the Astrometric Capabilities of the Hubble Space Telescope Fine Guidance Sensors

1991 ◽  
Vol 127 ◽  
pp. 68-76
Author(s):  
W.H. Jefferys ◽  
G.F. Benedict ◽  
R.L. Duncombe ◽  
O.G. Franz ◽  
L.W. Fredrick ◽  
...  
Keyword(s):  
Optical System ◽  
Reference Frames ◽  
Optical Axis ◽  
Hubble Space Telescope ◽  
Current Knowledge ◽  
Spherical Aberration ◽  
Radial Distance ◽  
Current Status ◽  
Space Telescope ◽  
Wavefront Error

AbstractThe Fine Guidance Sensors (FGSs) are the instrument of choice for most astrometric measurements with the Hubble Space Telescope (HST). The observed amount of spherical aberration in the Ritchey Chretien optical system does not affect positional measurements with perfectly aligned FGSs because they are interferometers. The FGSs combine wavefronts from points in the exit pupil with other points which are at the same radial distance from the optical axis. Asymmetric aberrations such as coma and astigmatism do affect the measured positions. The current knowledge of the HST wavefront error, the FGS operation and the implications for milliarcsecond relative astrometry are discussed. It is still planned to use the HST to tie the HIPPARCOS and VLBI Reference Frames together at the few milliarcsecond level.

Study of Three-Dimensional Optical Homogeneity of Fused Silica Prepared by Chemical Vapor Deposition

2017 ◽  
Vol 726 ◽  
pp. 465-469
Author(s):  
Zhu Feng Shao ◽  
Zai Kui Xiang ◽  
Yu Fen Wang ◽  
Mei Sui ◽  
Yi Wang Bao
Keyword(s):  
Chemical Vapor Deposition ◽  
Wave Front ◽  
Optical System ◽  
Vapor Deposition ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Chemical Vapor ◽  
Fused Silica ◽  
Optical Homogeneity

Optical homogeneity of the fused silica directly affects the wave-front quality of the optical system. Furthermore, three-dimensional optical homogeneity is required in order to produce high-precision prisms, because of its special optical demand. However, the three-dimensional optical homogeneity of fused silica is poor owing to the periodically grow laws based on vertical CVD technical in the process of ingots production. One circular and one square sample were prepared to measuring the three-dimensional optical homogeneity, founding that the vertical direction had worse optical homogeneity result compared to the horizontal direction. The constituents of the sample were tested and analyzed to found the inhomogeneity reason. The method was proposed to improve the three-dimensional optical homogeneity.

Collimate LED Light to Uniform Illumination with Refractive-Reflective Optical System

2014 ◽  
Vol 543-547 ◽  
pp. 658-661
Author(s):  
Chen Chen ◽  
Xiao Hui Zhang
Keyword(s):  
Wave Front ◽  
Uniform Distribution ◽  
Optical System ◽  
Total Efficiency ◽  
Optical Surface ◽  
Uniform Illumination ◽  
Led Light ◽  
Light Pattern

An optical system which collimate the light of LED uniformly is proposed in this paper. This optical system consist of two part of optical surface. First a TIR lens collimate all of the light of the LED parallel to the z axis. Then the first reflector redirect the collimating light to a uniform distribution and the second reflector collimate the uniform light pattern. The simulation result of the designed system shows that the uniformity of the output wave-front is 0.78 and the total efficiency of the system is 89.32%.

Atomic Resolution in Crystal Aperture Stem

1990 ◽  
Vol 48 (1) ◽  
pp. 236-237
Author(s):  
J T Fourie
Keyword(s):  
Optical System ◽  
Spherical Aberration ◽  
Three Dimensional ◽  
Transmission Function ◽  
Optical Systems ◽  
Bragg Angle ◽  
Electron Optical System ◽  
Intimate Contact ◽  
Diffraction Effects ◽  
Design Aspect

The attempts at improvement of electron optical systems to date, have largely been directed towards the design aspect of magnetic lenses and towards the establishment of ideal lens combinations. In the present work the emphasis has been placed on the utilization of a unique three-dimensional crystal objective aperture within a standard electron optical system with the aim to reduce the spherical aberration without introducing diffraction effects. A brief summary of this work together with a description of results obtained recently, will be given.The concept of utilizing a crystal as aperture in an electron optical system was introduced by Fourie who employed a {111} crystal foil as a collector aperture, by mounting the sample directly on top of the foil and in intimate contact with the foil. In the present work the sample was mounted on the bottom of the foil so that the crystal would function as an objective or probe forming aperture. The transmission function of such a crystal aperture depends on the thickness, t, and the orientation of the foil. The expression for calculating the transmission function was derived by Hashimoto, Howie and Whelan on the basis of the electron equivalent of the Borrmann anomalous absorption effect in crystals. In Fig. 1 the functions for a g220 diffraction vector and t = 0.53 and 1.0 μm are shown. Here n= Θ‒ΘB, where Θ is the angle between the incident ray and the (hkl) planes, and ΘB is the Bragg angle.

On the readiness of students to distance learning now

2021 ◽  
pp. 55-59
Author(s):  
O.G. Vasyukov ◽  
Keyword(s):  
Distance Education ◽  
Distance Learning ◽  
Software Package ◽  
Personal Computers ◽  
Current Time ◽  
Direct Training ◽  
Course Work ◽  
Home Computers ◽  
Microsoft Office

Examines the positive and negative sides of distance education in aspects of quality of education and economic efficiency of the distance learning software that are used in the training for the selected training areas/specialties. In the course of the research conducted by the method of questioning students, it was revealed that at the current time, 69.7% of students have none of the programs they need for further direct training of their profession on their home computers. Considering the provision of students with the software they need to study basic subjects, it was found that 24.5% of students have Microsoft Office 2007 or earlier installed on their personal computers (PCs) or laptops, that is, SOFTWARE that is already considered obsolete. Thus, almost every fourth student, when performing practical, laboratory, course work using a software package for working in the office, experiences difficulties. In the course of the research conducted by the method of questioning students, it was revealed that at the current time, 69.7% of students have none of the programs they need for further direct training of their profession on their home computers. Considering the provision of students with the software they need to study basic subjects, it was found that 24.5% of students have Microsoft Office 2007 or earlier installed on their personal computers (PCs) or laptops, that is, SOFTWARE that is already considered obsolete. Thus, almost every fourth student, when performing practical, laboratory, course work using a software package for working in the office, experiences difficulties. Why the computer works even slower and with various failures and failures. Moreover, the specified percentage may also be even higher, since 8.6% of students could not answer what OS they have installed. Studying in the traditional form of training, this lack of hardware and SOFTWARE is eliminated, since in the University’s computer classes, there are PCs that support reliable operation with Windows 10 and Microsoft Office 2010 and are protected from viruses and attacks by installed and constantly updated antivirus programs. The article reveals the problems that affect the quality of students’ education when switching to distance learning. Namely, the absence or non-compliance of Hardware and SOFTWARE for students’ computers and laptops with modern requirements for Hardware and SOFTWARE for performing teachers’ tasks. The author concludes that when switching to full distance education in technical specialties, the state will lose, according to the most optimistic forecasts, from 19.8 to 69.7% of well-prepared students only because their education does not meet modern requirements.

scholarly journals ADMINISTRATIVE PROCEDURE FOR THE PROVISION OF ELECTRONIC SERVICES IN THE FORM OF A DECLARATION (NOTIFICATION) BY PHYSICAL PERSONS TO THE STATE ARCHITECTURAL AND CONSTRUCTION INSPECTION

2019 ◽  
pp. 74-77
Author(s):  
A. R. Ishkhanian
Keyword(s):  
Digital Signature ◽  
Software Package ◽  
The State ◽  
Scientific Article ◽  
Administrative Procedure ◽  
Electronic Service ◽  
Service Consumer ◽  
Construction Inspection ◽  
The Moment

The scientific article is devoted to the coverage of the administrative procedure for providing electronic services by the State Architectural and Construction Inspectorate of Ukraine. Different approaches to the concept of administrative procedure in terms of e-services provision are discussed. The stages of the procedure of providing electronic service in the form of submission of a declaration (notification) by individuals are characterized. It is established that before commencing the process of submission of the declaration (message), the service consumer must have a personal key and a valid enhanced certificate, which will be used during the submission process to affix an electronic digital signature to the form with the declaration (message). You can obtain enhanced key certificates at an accredited key certification center. Thus, at the moment the service supports certificates issued by the certification center of the information and reference department of the Ministry of Revenue and Collections of Ukraine. Install a Java computing software package on your computer and enable JavaScript scripts to run in your browser. Please note that detailed Java installation instructions are available at http://java.com/download/installed.jsp. You can download Java directly for Windows from http://www.java.com/download/windows_xpi.jsp. How to enable JavaScript scripts in your browser (http://www.enable-javascript.com/en/). It is concluded that the procedure of providing the service in electronic form, for example, the submission of a declaration (notification) by the state architectural and construction inspection of Ukraine is regulated in detail on the official website and still needs to improve the quality of the provision of these services in the form of simplification and accessibility for all consumers services.

A NEW METHOD OF LENS CENTERING IN THE OPTICAL SYSTEM BY USING SPECIAL MOUNT

2021 ◽  
pp. 137-144
Author(s):  
Bao Bui Dinh
Keyword(s):  
Optical System ◽  
Optical Axis ◽  
Assembly Process ◽  
Optical Surface ◽  
Lens System ◽  
High Quality ◽  
Manufacturing Equipment ◽  
Influence Coefficients ◽  
Process Solutions

Decentration in lens systems (for example objectives) significantly degrades the quality of image, such as the coma. In order to reduce lens decentration, the lenses are centered while manufacturing, while gluing, while attachment in the mounts. Significant decrease in the lenses decentering in the mounts is achieved by using a special manufacturing equipment, which allow combining the optical axis of the lens with the base axis of the mount in assembly process. Solutions for coma's alignment by shifting, tilting and rotation their components are also provided in the construction of high-quality objectives (microscopes [1-7], photolithographic, aerophotographic). For optimization of methods for such adjustment the influence coefficients of decentering of each optical surface of the lens system on the value and sign of coma must be calculated and taken into account. In this paper, we propose a special mounting which combined with the Opticentric of Trioptics device to center the lenses. The results show that the decentering is significantly reduced (0.9µm) compared to (44.2µm) with using a reference mount.

ON THE APPLICATION OF DISPERSION ANALYSIS FOR QUALITY ASSESSMENT OF A QUARTZ UV IRRADIATOR

2021 ◽  
pp. 52-57
Author(s):  
D. D. Balandin ◽  
O. L. Lyubimtseva
Keyword(s):  
Analysis Of Variance ◽  
Software Package ◽  
Bactericidal Effect ◽  
Dispersion Analysis ◽  
Anova Model ◽  
Urgent Task ◽  
Uv Lamp ◽  
Quality Of Products ◽  
Uv C

Ensuring and improving the quality of products is currently an urgent task implemented through product quality management. In connection with the spread of the COVID-19 virus, Rospotrebnadzor recommends the use of quartz lamps when disinfecting premises. The article discusses the issue of assessing the quality of a device for home use of a quartz ultraviolet irradiator OUFK-01. In accordance with the WHO recommendations, the irradiation indicator became the main one for the study. The study was carried out using an ANOVA model with several iterations. Purpose of the study: to study the variability of the irradiance index in different UV ranges depending on the source of UV radiation (UV lamp) of the ultraviolet irradiator OUFK-01. The main advantage of the analysis of variance was used – the ability to consider the interaction of various factors. The conclusions that were formulated based on the results of analysis of variance suggest that the quality of the OUFK-01 irradiator has changed. Data processing was carried out using the MS EXCEL software package. The article provides a rationale for what is meant by “quality improvement”, namely, in order not to violate the bactericidal effect, it is necessary to reduce the UV-A and UV-B ranges to acceptable values, since the effect of UV-C rays has not been fully studied, then the irradiance should be increased to the permissible wavelength range. A comparative analysis of successively modified products showed that the quality of the device increased with the replacement of the UV lamp.

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