Focal surface attitude detection for LAMOST

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.

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Astrometry With Schmidt Telescopes

International Astronomical Union Colloquium ◽

10.1017/s025292110010661x ◽

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.

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Deep Learning-Based Opponent Aircraft Attitude Detection in Autonomous Air Combat

Journal of Aerospace Information Systems ◽

10.2514/1.i010684 ◽

2019 ◽

Vol 16 (4) ◽

pp. 162-167

Author(s):

Yiqun Dong

Keyword(s):

Deep Learning ◽

Air Combat ◽

Attitude Detection

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Attitude Detection for One-Round Conversation

Proceedings of the Twelfth ACM International Conference on Web Search and Data Mining ◽

10.1145/3289600.3291038 ◽

2019 ◽

Cited By ~ 3

Author(s):

Zhaohao Zeng ◽

Ruihua Song ◽

Pingping Lin ◽

Tetsuya Sakai

Keyword(s):

Attitude Detection

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

Pure and Applied Geophysics ◽

10.1007/bf00876581 ◽

1993 ◽

Vol 140 (4) ◽

pp. 641-653

Author(s):

A. Bottari ◽

B. Federico ◽

M. Pietrafesa ◽

A. Teramo

Keyword(s):

Travel Time ◽

Focal Surface

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The Design of the Attitude Detection Algorithm of Underwater Robot

2016 Sixth International Conference on Instrumentation & Measurement, Computer, Communication and Control (IMCCC) ◽

10.1109/imccc.2016.165 ◽

2016 ◽

Author(s):

Xueting Zhang ◽

Bing Xia ◽

Taowei Tao ◽

Ming Zhang

Keyword(s):

Detection Algorithm ◽

Underwater Robot ◽

Attitude Detection

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

Applied Sciences ◽

10.3390/app10020712 ◽

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.

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