scholarly journals Arrayed wide-field astronomical camera system for spectroscopic surveys on Extremely Large Telescopes: system architecture, proof-of-concept, and enabling technologies

2021 ◽  
Vol 7 (03) ◽  
Author(s):  
Hanshin Lee ◽  
Menelaos K. Poutous
Keyword(s):  
System Architecture ◽  
Wide Field ◽  
Proof Of Concept ◽  
Camera System ◽  
Enabling Technologies ◽  
Large Telescopes

scholarly journals An Overview of LoRaWAN

2021 ◽  
Vol 19 ◽  
pp. 231-239
Author(s):  
Biswajit Paul
Keyword(s):  
System Architecture ◽  
Communication Protocol ◽  
Data Rate ◽  
Network Coverage ◽  
Enabling Technology ◽  
Long Distance ◽  
Ism Band ◽  
Enabling Technologies ◽  
Distance Communication

LoRa is an IoT enabling technology which is particularly suitable for low data rate applications. The technology can achieve extended network coverage while operating in unlicensed ISM band and falls into the category of Low­Power­Wide­Area­Networks (LPWANs) technologies. Among the non­cellular based LPWAN enabling technologies, LoRa has got remarkable attention due to its fast adoption by industries. LoRa through wireless modulation enables the end­nodes to establish long distance communication while LoRaWAN refers to the communication protocol and system architecture. In this paper, an overview of LoRaWAN is presented.

scholarly journals Astrometry with the Space Telescope Wide-Field/Planetary Camera

1983 ◽  
Vol 62 ◽  
pp. 246-253
Author(s):  
W. A. Baum
Keyword(s):  
Wide Field ◽  
Camera System ◽  
Space Telescope ◽  
Nearby Stars

Although the Space Telescope Wide-Field/Planetary Camera is not primarily an astrometric instrument, it is expected to have some astrometric capability. Moreover, one of its possible astrometric applications is of unusually high scientific importance, namely, an attempt to detect the presence of planets around nearby stars. Let me therefore adopt that application as an example for discussing the anticipated astrometric performance of the camera system. It will be expeditious to make use of some diagrams that I have presented previously elsewhere, so part of the story may sound familiar (Baum 1979a, 1979b, 1980a, 1980b; Baum, Thomsen, and Kreidl 1981).

scholarly journals Active optics in astronomy – modeling of deformable substrates: freeform surfaces for FIREBall and MESSIER

2018 ◽  
Vol 27 (5-6) ◽  
Author(s):  
Gérard Rene Lemaitre
Keyword(s):  
Adaptive Optics ◽  
Large Scale ◽  
Wide Field ◽  
Freeform Surfaces ◽  
Aspheric Surfaces ◽  
Massive Black Holes ◽  
Active Optics ◽  
Minimum Number ◽  
Co Addition ◽  
Large Telescopes

AbstractActive optics techniques on large telescopes and astronomical instrumentations provide high imaging quality. For ground-based astronomy, the co-addition of adaptive optics again increases angular resolution up to providing diffraction-limited imaging at least in the infrared. Active and adaptive optics marked milestone progress in the detection of exoplanets, super-massive black holes, and large-scale structure of galaxies. This paper is dedicated to highly deformable active optics that can generate non-axisymmetric aspheric surfaces – or freeform surfaces – by use of a minimum number of actuators: a single uniform load acts over the surface of a vase-form substrate whilst under reaction to its elliptical perimeter ring. Two such instruments are presented: (1) the Faint Intergalactic Redshifted Emission Balloon (FIREBall) telescope and multi object spectrograph (MOS) where the freeform reflective diffraction grating is generated by replication of a deformable master grating, and (2) the MESSIER wide-field low-central-obstruction three-mirror-anastigmat (TMA) telescope proposal where the freeform mirror is generated by stress figuring and elastic relaxation. Freeform surfaces were obtained by plane super-polishing. Preliminary analysis required use of the optics theory of 3rd-order aberrations and elasticity theory of thin elliptical plates. Final cross-optimizations were carried out with Zemax raytracing code and Nastran FEA elasticity code in order to determine geometry of the deformable substrates.

scholarly journals Synchronization of System Architecture and Safety Models: a Proof of Concept

2019 ◽  
Author(s):  
Michel Batteux ◽  
Jean-Yves Choley ◽  
Faida Mhenni ◽  
Tatiana Prosvirnova ◽  
Antoine Rauzy
Keyword(s):  
System Architecture ◽  
Proof Of Concept ◽  
Safety Models

scholarly journals Imaging Spectroscopy on Very Large Telescopes

1984 ◽  
Vol 79 ◽  
pp. 515-517
Author(s):  
Paul Atherton
Keyword(s):  
Fourier Transform ◽  
Spatial Information ◽  
Broad Band ◽  
Imaging Spectroscopy ◽  
Wide Field ◽  
Two Dimensional ◽  
Imaging Spectrometer ◽  
Resolution Element ◽  
Fabry Perot ◽  
Large Telescopes

Imaging Spectroscopy is a technique in which a spectrum is obtained for each spatial resolution element across a wide field. The data is essentially 3-D, and may be viewed as a series of monochromatic images, or as a two dimensional array of spectra. A device generating such data may be called an imaging spectrometer. In a previous paper (Atherton, 1983 SPIE 445, 535) three different imaging spectrometers - based on grating, Fabry-Perot and Fourier Transform devices - were compared in terms of their ability to obtain spectral and spatial information over a wide field and broad band, to the same spectral resolution and S/N ratio, using the same detector array. From such a study it is clear that interferometer based devices are significantly faster than conventional grating spectrographs.

Tomographic control for wide field AO systems on extremely large telescopes

2010 ◽  
Author(s):  
C. Petit ◽  
J.-M. Conan ◽  
T. Fusco ◽  
B. Neichel
Keyword(s):  
Wide Field ◽  
Large Telescopes

scholarly journals Advanced Wide-Field Broad-Passband Refracting Field Correctors for Large Telescopes

1984 ◽  
Vol 79 ◽  
pp. 519-548 ◽  
Author(s):  
H.W. Epps ◽  
J.R.P. Angel ◽  
E. Anderson
Keyword(s):  
Image Quality ◽  
Atmospheric Dispersion ◽  
Wide Field ◽  
Atmospheric Refraction ◽  
Optical Elements ◽  
Large Telescopes ◽  
The University ◽  
Near Future ◽  
Optical Manufacturing ◽  
Made In

AbstractA preliminary 30-arcmin prime focus (f/2.0) refracting field corrector system for the University of California Ten-Meter Telescope (UC TMT) is presented which features 1/4-arcsec images containing more than 80% of the energy, over limited passbands within the wavelength range λ3300Å to λ1.0µ. Provision has been made in this system for an atmospheric dispersion corrector (ADC) but same has not yet been realized. Optical elements herein are small enough that this design could be scaled up to a Fifteen-Meter NNTT/SMT.A compact 40-arcmin internal Cassegrain (f/1.75 hyperbola to f/5.0) broad-passband (λ3300Å to λ1.0µ) corrector, suitable for imaging and multi-object spectroscopy at the UC TMT, is presented which features 1/4-arcsec images containing more than 90% of the energy when averaged over field angle and color.Three 60-arcmin external Cassegrain correctors for 300-inch f/1.8 and f/2.0 parabolic primary mirrors are presented which are suitable for a Fifteen-Meter NNTT/MMT. Image quality is comparable to the UC TMT Cassegrain corrector and it exceeds that of the UC TMT preliminary prime focus corrector system by a substantial margin. Each of these correctors contains an ADC which has been implemented in one example, eliminating 4.0 arcsec of differential atmospheric refraction with an rms residual of +/-0.10 arcsec over the broad passband (λ3300Å to λ1.0µ). A 60-arcmin external Cassegrain (f/1.8 extreme hyperbola to f/4.5) corrector with ADC yields yet a factor two in image quality but said hyperbolic primary mirror would be incompatible with angular field requirements in the thermal infrared.A (300-inch) 40-arcmin external Cassegrain (f/1.0 parabola to f/4.0) broad-passband (λ3300Å to λ1.0µ) corrector with ADC is presented. Image quality is comparable to the previous Cassegrain correctors. The practicality of this design, together with recent advances in optical manufacturing capability of large, fast, nonspherical optics, suggests that relatively inexpensive compact telescopes of very large collecting area may be possible in the near future.

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