Focal surface for EUSO telescope

2003 ◽  
Author(s):  
Hirohiko M. Shimizu ◽  
M. Ameri ◽  
F. Cadoux ◽  
Osvaldo Catalano ◽  
C. Chapron ◽  
...  
Keyword(s):  
Focal Surface

scholarly journals Focal Surface Detection of High Numerical Aperture Objective Lens Based on Differential Astigmatic Method

2021 ◽  
Vol 13 (4) ◽  
pp. 1-8
Author(s):  
Jia-Lin Du ◽  
Wei Yan ◽  
Li-Wei Liu ◽  
Fan-Xing Li ◽  
Fu-Ping Peng ◽  
...  
Keyword(s):  
Numerical Aperture ◽  
Objective Lens ◽  
High Numerical Aperture ◽  
Surface Detection ◽  
Focal Surface

scholarly journals Use of CCDs in Schmidt Telescopes for the Investigation of Hα Emission of Flare Stars

1995 ◽  
Vol 148 ◽  
pp. 60-64
Author(s):  
Gábor Szécsényi-Nagy
Keyword(s):  
Open Clusters ◽  
Good Resolution ◽  
Focal Surface ◽  
Stellar Flares ◽  
Recent Developments ◽  
Traditional Mode ◽  
Hα Emission ◽  
Flare Stars ◽  
Characteristic Features ◽  
Silicon Based

AbstractThe use of Schmidt telescopes in their traditional mode for the detection of stellar flares and for the UV and PG photometry of these stars proved to be very productive. The fast optical system and reliable sensitivity of modern photographic emulsions resulted in a photometric time-resolution of several minutes even in the case of distant objects. One of the most important characteristics of flare stars may be the tendency for coexistence with more massive and more luminous member stars of young stellar aggregates (mainly open clusters). Although the vast majority of flare stars discovered seem to belong to clusters, a great many of them are neighbours of our sun. These can be investigated in depth because a sufficient number of their photons can be collected and recorded in narrow photometric bands or even in spectra of good resolution. The direct comparison of solar vicinity flare stars with flare-active members of distant clusters has been almost impossible. However recent developments in silicon-based photon-detecting technology offer the advantage of incredibly high detector quantum efficiency (DQE) in many spectral regions where photographic materials never reached an acceptable level. Hα emission is one of the most characteristic features of flare stars, and the wavelength of Hα photons fits extremely well with the peak of the spectral sensitivity curves of silicon photon detectors. CCD chips placed in the focal surface of Schmidt telescopes seem to be very promising for the future investigation of Hα emission of flare stars.

scholarly journals Astrometry With Schmidt Telescopes

1984 ◽  
Vol 78 ◽  
pp. 217-224
Author(s):  
C A Murray
Keyword(s):  
Reference Frame ◽  
Proper Motions ◽  
Large Area ◽  
Full Field ◽  
Potential Value ◽  
Focal Surface ◽  
Single Plate ◽  
Trigonometric Parallaxes ◽  
The Absolute

Photographic astrometry, including work with Schmidt telescopes, can be divided into two main fields, (i) the measurement of positions of objects relative to a reference frame of stars with known celestial coordinates, and (ii) the measurement of relative proper motions and trigonometric parallaxes from a series of plates taken on the same field. The former demands a knowledge of the absolute transformation between angles on the sky and measurements on a plate, whereas in the latter we are only interested in differential transformations from plate to plate. The potential value of Schmidt telescopes for both these fields of astrometry lies in the large area of sky and range of magnitude which can be imaged on a single plate. The former advantage is however, to some extent offset by the curvature of the focal surface which means that, in order to utilize the full field the plates must be constrained to the form of the focal surface during exposure.

Procedure of reduction of travel-time curves ofP andS waves at the focal surface

1993 ◽  
Vol 140 (4) ◽  
pp. 641-653
Author(s):  
A. Bottari ◽  
B. Federico ◽  
M. Pietrafesa ◽  
A. Teramo
Keyword(s):  
Travel Time ◽  
Focal Surface

scholarly journals Variable Curvature Displays: Optical Designs and Applications for VR/AR/MR Headsets

2020 ◽  
Vol 10 (2) ◽  
pp. 712
Author(s):  
Eduard Muslimov ◽  
Thibault Behaghel ◽  
Emmanuel Hugot ◽  
Kelly Joaquina ◽  
Ilya Guskov
Keyword(s):  
Virtual Reality ◽  
High Resolution ◽  
Field Of View ◽  
Projection System ◽  
Object Position ◽  
Focal Surface ◽  
Variable Curvature ◽  
Starting Point ◽  
Low Distortion ◽  
Aberration Theory

In the present paper, we discuss the design of a projection system with curved display and its enhancement by variably adjusting the curvature. We demonstrate that the focal surface curvature varies significantly with a change of the object position and that it can easily be computed with the Seidel aberration theory. Using this analytically derived curvature value as the starting point, we optimise a refocusable projection system with 90 ° field of view and F / # = 6.2 . It is demonstrated that such a system can provide stable image quality and illumination when refocusing from infinity to 1.5 m. The gain in spatial resolution is as high as 1.54 times with respect to a flat focal surface. Furthermore, we prove that a silicon die can be curved to the required shape with a safety factor of 4.3 in terms of the mechanical stress. Finally, it is shown that the developed system can be used in a virtual reality headset providing high resolution, low distortion and a flexible focusing mode.

Properties of Cyclide Dyupen and Their Application. Part 1

2015 ◽  
Vol 3 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Сальков ◽  
Nikolay Sal'kov
Keyword(s):  
Nineteenth Century ◽  
Contact Line ◽  
Classical Problem ◽  
Descriptive Geometry ◽  
Practical Application ◽  
Surfaces Of Revolution ◽  
Early Nineteenth Century ◽  
Focal Surface ◽  
Lines Of Curvature ◽  
And Task

In the training course in descriptive geometry we consider the class of surfaces formed by circles and named "Circular surface. Within this class of surfaces is the so-called kanalowe surface. Under a lie cyclide belong to canalave surfaces, but in the course of descriptive geometry, their formation is not considered. Under a lie cyclide were discovered by Pierre Charles Francois Dyupen in the early nineteenth century and named in his honor. He dyupen was a disciple of Gaspard Monge, like many great scientists in France at that time. Under a lie cyclide usually represented as envelopes of a family of spheres tangent to three given. Under a lie – the only surface whose focal surface degenerates into a line, and all lines of curvature are circles. Particular cases of ticlid cyclide is a torus, and conical and cylindrical surfaces of revolution. The paper discusses the analytical representation of the focal lines for the General case of a job under a lie cyclide. It is analytically proved that the contact line inscribed in cyclide spheres are circles, and degenerate in the focal curve on the surface is a curve of the В учебном курсе начертательной геометрии из- учается класс поверхностей, образованный окруж- ностями и названный «Циклические поверхности» [5; 8; 12]. Внутри этого класса поверхностей есть так называемые каналовые поверхности. Циклиды Дюпена принадлежат к каналовым поверхностям, более того, они являются частным случаем [2–4; 6] этих поверхностей, но в курсе начертательной гео- метрии их формирование не рассматривается. Циклиды Дюпена были открыты Пьером Шарлем Франсуа Дюпеном (1784–1873) в начале XIX в. и названы в его честь [14]. Дюпен (рис. 1) был учени- ком Гаспара Монжа, как и многие великие ученые Франции того времени, и являлся почетным членом Петербургской академии наук c 20 декабря 1826 г. second order. Identified some (nine) properties of this surface. As a practical application of ticlid cyclide solved such well-known classical problem as the problem of Apollonius (about Casa-NII three circles fourth) and task Farm (touch four spheres fifth) using again the classic way – with a ruler and a compass. In the first part of the article is only three ways to solve the problem of Apollonius solely by means of compass and ruler, using the properties of cyclide Dyupen.

scholarly journals THE JEM-EUSO MISSION: OBSERVATION OF ULTRA-HIGH ENERGY COSMIC RAYS FROM SPACE

2013 ◽  
Vol 23 ◽  
pp. 329-334
Author(s):  
◽  
M. RICCI
Keyword(s):  
Cosmic Rays ◽  
Space Station ◽  
Infrared Camera ◽  
High Energy ◽  
Ultra High Energy ◽  
Significant Information ◽  
Full Field ◽  
High Energy Cosmic Rays ◽  
Focal Surface ◽  
Fresnel Lenses

The Extreme Universe Space Observatory on Japanese Experiment Module (JEM-EUSO) is a science mission planned to be launched in 2017 to the International Space Station (ISS) to investigate the nature and origin of Ultra High Energy Cosmic Rays (UHECR) beyond energy 3 × 1019 eV. JEM-EUSO is a wide-angle telescope (60 degrees full field of view) and consists of a high-transmittance Fresnel lenses 2.5 m in diameter, an advanced photo-sensitive detector at the focal surface and a suitable electronics. An infrared camera and a LIDAR system will also be used to monitor the Earth's atmosphere and provide significant information on cloud coverage. The present status of advancement of the mission is reported.

scholarly journals Focal surface attitude detection for LAMOST

2020 ◽  
Vol 20 (11) ◽  
pp. 181
Author(s):  
Tian-Zhu Hu ◽  
Yong Zhang ◽  
Xiang-Qun Cui ◽  
Ye-Ping Li ◽  
Xiu-Shan Pan ◽  
...  
Keyword(s):  
Focal Surface ◽  
Attitude Detection

scholarly journals The Detection of UHECRs with the EUSO-TA Telescope

2019 ◽  
Vol 210 ◽  
pp. 05005
Author(s):  
F. Bisconti ◽  
J.W. Belz ◽  
M.E. Bertaina ◽  
M. Casolino ◽  
T. Ebisuzaki ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Laser Pulses ◽  
High Energy ◽  
Field Of View ◽  
Detection Capability ◽  
Fluorescence Detector ◽  
High Energy Cosmic Rays ◽  
Focal Surface ◽  
Fresnel Lenses ◽  
Fluorescence Light

EUSO-TA is a cosmic ray detector developed by the JEM-EUSO (Joint Experiment Missions for Extreme Universe Space Observatory) Collaboration, observing during nighttime the fluorescence light emitted along the path of extensive air showers in the atmosphere. It is installed at the Telescope Array site in Utah, USA, in front of the fluorescence detector station at Black Rock Mesa. It serves as a ground-based pathfinder experiment for future space-based missions. EUSO-TA has an optical system with two Fresnel lenses and a focal surface with 6 × 6 multi-anode photomultiplier tubes with 64 channels each, for a total of 2304 channels. The overall field of view is ∼10.6°× 10.6°. This detector technology allows the detection of cosmic ray events with high spatial resolution, having each channel a field of view of about ∼0.2° × 0.2° and a temporal resolution of 2.5 µs. First observations of ultra-high energy cosmic rays revealed the cosmic ray detection capability of EUSO-TA. The foreseen upgrade of EUSO-TA will improve the efficiency of the detector and will increase the statistics of detected events. In this work we present recent results of the detection capability of EUSO-TA and its limits. Moreover, other results about the analysis of laser pulses, stars and meteors will be discussed.

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