Teses / dissertações sobre o tema "Astronomical instruments"
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1
饒勇 e Yong Rao. "The astronomical observation system of 12" telescope: its automatic control system and astronomical application". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1997. http://hub.hku.hk/bib/B31214587.
2
Cochrane, William Andrew. "The design and characterisation of miniature robotics for astronomical instruments". Thesis, Heriot-Watt University, 2015. http://hdl.handle.net/10399/2916.
Resumo:
Micro robotics has the potential to improve the efficiency and reduce cost of future multi-object instruments for astronomy. This thesis reports on the development and evolution of a micro autonomous pick-off mirror called the Micro Autonomous Positioning System (MAPS) that can be used in a multi-object spectrograph. The design of these micro-autonomous pick-off mirrors is novel as they are capable of high precision positioning using electromagnetic propulsion through utilising non-conventional components and techniques. These devices are self-driven robotic units, which with the help of an external control system are capable of positioning themselves on an instruments focal plane to within 24 μm. This is different from other high precision micro robotics as they normally use piezoelectric actuators for propulsion. Micro robots have been developed that use electromagnetic motors, however they are not used for high precision applications. Although there is a plethora of literature covering design, functionality and capability of precision micro autonomous systems, there is limited research on characterisation methods for their use in astronomical applications. This work contributes not only to the science supporting the design of a micro-autonomous pick-off mirror but also presents a framework for characterising such miniature mechanisms. The majority of instruments are presented with a curved focal plane. Therefore, to ensure that the pick-off mirrors are aligned properly with the receiving optics, either the pick-off mirror needs to be tipped or the receiving optics repositioned. Currently this function is implemented in the beam steering mirror (i.e. the receiving optics). The travel range required by the beam steering mirror is relatively large, and as such, it is more difficult to achieve the positional accuracy and stability. By incorporating this functionality in the pick-off mirror, the instrument can be optimised in terms of size, accuracy and stability. A unique self-adjusting mirror (SAM) is thus proposed as a solution and detailed. As a proof-of-concepts both MAPS and SAM usability in multi-object spectrographs was evaluated and validated. The results indicate their potential to meet the requirements of astronomical instruments and reduce both the size and cost.
3
Porter, Martin John. "A CCD camera system for use in echelle spectroscopy /". St. Lucia, Qld, 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17953.pdf.
4
Brooks, Randall Chapman. "The precision screw in scientific instruments of the 17th-19th centuries : with particular reference to astronomical, nautical and surveying instruments". Thesis, University of Leicester, 1989. http://hdl.handle.net/2381/8446.
Resumo:
Published articles have been removed from the Appendices of the electronic copy of this thesis due to third party copyright restrictions. The complete version can be consulted at the University of Leicester Library.
5
McGee, P. K. "Optical studies in high-energy astrophysics /". Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phm14485.pdf.
6
MacLachlan, David Guillaume. "Development of photonic technologies for astronomical instruments using ultrafast laser inscription". Thesis, Heriot-Watt University, 2017. http://hdl.handle.net/10399/3281.
Resumo:
Recently there has been a desire to apply photonic concepts and technologies to astronomical applications, with the aim of replacing traditional bulk optic instruments. This astrophotonic approach is envisioned to produce compact devices that have the potential to provide the unprecedented precision and stability required for current astronomical goals, such as the detection of Earth-like exoplanets capable of supporting life. The work in this thesis covers the investigation of the technique of Ultrafast Laser Inscription (ULI) to create the building blocks that may lead to a fully integrated compact spectrograph for astronomy. Unlike conventional fabrication technologies, ULI allows custom three-dimensional optical devices to be directly inscribed within a bulk substrate. Volume gratings with high first order diffraction efficiencies optimised for a variety of wavelengths are demonstrated, with a view to providing efficient gratings for the midinfrared wavelength range. Initially the mid infrared transmitting material GLS was used to create gratings with a first order efficiency of 63 % up to a wavelength of 1.35 μm. Anti-reflection coatings were applied to GLS and gratings with an efficiency of 95 % at 1.02 μm were produced. A second material, IG2 was used and diffraction gratings with a first order efficiency of 63 % were produced, which were efficient up to a wavelength of 2.5 μm, with thicker gratings produced which have yet to be characterised in a mid-infrared setup. These developments show that practical mid-infrared volume gratings can be produced by the process of ULI. Photonic reformatters have also been developed to reshape a multimode telescope point spread function into a pseudo-slit, suitable as an input for a diffraction-limited spectrograph. Two device designs were investigated. The first was a fully integrated ULI component which, tested in the laboratory reformatted a multimode input at 1550 nm into a slit, single mode in one axis and highly multimode in the orthogonal axis with an efficiency of 66 %. The device was tested on-sky at the William Herschel Telescope and performed with an efficiency of 19.5 % over the wavelength range 1450 to 1610 nm. The second, improved device combined a ULI component with a multicore fibre component, and performed with a similar performance in the laboratory demonstrating an efficiency of 69 %, but a much improved on sky efficiency of 53 % showing a potential for such devices to be used as an input for a diffraction limited spectrograph.
7
Kenyon, Suzanne Laura Physics Faculty of Science UNSW. "A universe of sky and snow: site-testing for optical astronomy at Dome C, Antarctica". Awarded by:University of New South Wales. Physics, 2007. http://handle.unsw.edu.au/1959.4/40822.
Resumo:
The unique advantages for astronomy on the Antarctic plateau are now well established. In particular, Dome C, Antarctica is potentially one of the best new sites for optical, infrared and sub-millimeter astronomy, presenting the opportunity to build unique astronomical instruments. Located high on the Antarctic plateau, Dome C offers low wind, clear skies, and negligible precipitation. This thesis addresses three additional properties of the site relevant to optical astronomy-sky brightness, atmospheric extinction and optical turbulence. The sky at an optical astronomy site must be dark, and the atmosphere very clean with minimal light extinction. At present little is known from an astronomer's perspective about the optical sky brightness and atmospheric extinction at most Antarctic sites. The high latitude of Dome C means that the Sun spends a relatively small amount of time far below the horizon, implying longer periods of astronomical twilight and less optical dark time than other sites, especially those close to the equator. We review the contributions to sky brightness at high-latitude sites, and calculate the amount of usable dark time at Dome C. We also explore the implications of the limited sky coverage of high-latitude sites, and review optical extinction data from the South Pole. A proposal to extend the amount of usable dark time through the use of polarising filters is examined, and we present the design and calibration of an instrument (called Nigel) to measure the brightness, spectrum and temporal characteristics of the twilight and night sky. The atmospheric turbulence profile above an astronomical site limits the achievable resolution and sensitivity of a telescope. The atmospheric conditions above high plateau Antarctic sites are different to temperate sites; the boundary layer of turbulence is confined very close to the surface, and the upper atmosphere turbulence very weak. We present the first winter-time turbulence profiles of the atmosphere above Dome C, and characterise the site in terms of the achievable precision for photometry and astrometry, and the isoplanatic angle and coherence time for the adaptive optics.
8
Saklatvala, George. "A functional approach to the analysis of millimetre wave and infrared astronomical instruments". Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611293.
9
Bilāl, Muḥammad Luʼī Ṣūfī ʻAbd al-Raḥmān ibn ʻUmar. "al-Asṭrūlāb fī al-turāth al-ʻilmī al-ʻArabī risālah fī al-ʻamal bi-al-asṭrūlāb li-ʻAbd al-Raḥmān al-Ṣūfī /". [Aleppo] : Jāmiʻat Ḥalab, Maʻhad al-Turāth al-ʻIlmī al-ʻArabī, 1994. http://books.google.com/books?id=K8_aAAAAMAAJ.
10
Robinson, Matthew. "Development of planar technology for focal planes of future radio to sub-millimetre astronomical instruments". Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/development-of-planar-technology-for-focal-planes-of-future-radio-to-submillimetre-astronomical-instruments(dd2876aa-ff1a-4ae7-903f-a8228f3fc85f).html.
Resumo:
Receiver systems utilising planar technologies are prevalent in telescopes observing at radio to sub-millimetre wavelengths. Receiver components using planar technologies are generally smaller, have reduced mass and are cheaper to manufacture than waveguide-based alternatives. Given that modern-day detectors are capable of reaching the fundamental photon noise limit, increases in the sensitivity of telescopes are frequently attained by increasing the total number of detectors in the receivers. The development of components utilising planar technologies facilitates the demand for large numbers of detectors, whilst minimising the size, mass and manufacturing cost of the receiver. After a review and study of existing concepts in radio to sub-mm telescopes and their receivers, this thesis develops planar components that couple the radiation from the telescope's optics onto the focal plane. Two components are developed; a W- band (75-110 GHz) planar antenna-coupled flat mesh lens designed for the receiver of a Cosmic Microwave Background (CMB) B-mode experiment, and an L-band (1- 2 GHz) horn-coupled planar orthomode transducer designed for the receiver of the FAST telescope. The first developments of a planar antenna-coupled flat mesh lens are presented. The design is driven by the requirement to mitigate beam systematics to prevent pollution of the CMB B-mode signal. In the first instance, a waveguide-coupled mesh lens is characterised. The radiation patterns of the waveguide-coupled mesh lens have -3 dB beam widths between 26 and 19 degrees, beam ellipticity <10%, and cross-polarisation.
11
Ren, Deqing. "New techniques of multiple integral field spectroscopy". Thesis, Durham University, 2001. http://etheses.dur.ac.uk/3800/.
Resumo:
The work of this thesis is to investigate new techniques for Integral Field Spectroscopy (IPS) to make the most efficient use of modem large telescopes. Most of the work described is aimed at the FMOS for the SUBARU 8m telescope. Although this is primarily a system for Multiple Object Spectroscopy (MOS) employing single fibres, there is an option to include a multiple-IFS (MIPS) system. Much of this thesis is therefore aimed at the design and prototyping of critical systems for both the IPS and MOS modes of this instrument. The basic theory of IFU design is discussed first. Some particular problems are described and their soludons presented. The design of the MIPS system is described together with the construction and testing of a prototype deployable IFU. The assembly of the pickoff/fore-optics, microlens array and fibre bundle and their testing are described in detail. The estimated performance of the complete module is presented together with suggestions for improving the system efficiency which is currently limited by the performance of the microlens array. The prototyping of the MIPS system is supported by an extensive programme of testing of candidate microlens arrays. Another critical aspect of the instrument is the ability to disconnect the (IPS and MOS) fibre input which is installed on a removable prime focus top-end ring from the spectrographs which are mounted elsewhere on the telescope. This requires high-performance multiple fibre connectors. The designs of connectors for the MOS and IPS modes are described. Results from the testing of a prototype for the MOS mode are presented. This work is supported by a mathematical model of the coupling efficiency which takes into account optical aberrations and alignment errors. The final critical aspect of FMOS which has been investigated is the design of the spectrographs. The baseline system operates in the near-infrared (NIR) but an additional visible channel is an option. Efficient designs for both the visible and NIR systems are presented. The design of the NIR spectrograph presents challenges in the choice of materials for the doublet and triplet lenses employed. The choice of material and the combinations in which they can be used are described. This thesis shows that all these critical aspects of FMOS have good solutions that will result in good performance of the whole instrument. For the multiple IFU system, the prototype demonstrates acceptable performance which can be made excellent by the use of a better microlens array. The multiple fibre connector prototype already indicates excellent performance. Finally, the spectrograph designs presented should result in high efficiency and good image quality.
12
Bounissou, Sophie. "”On-chip” astronomical instrumentation : bringing polarimetric and spectroscopic capabilities to the detector level". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS400.
Resumo:
Cette thèse étudie la possibilité d'intégrer plusieurs fonctions instrumentales au sein de la matrice de bolomètres pour les observations dans le domaine du sub-millimétrique. Ceci est désormais envisageable grâce aux progrès des micro-technologies.Dans un premier temps, nous avons optimisé le design des pixels polarimétriques inventés pour l'instrument B-BOP du futur observatoire spatial SPICA. Ce travail a notamment permis de quantifier la cross-polarisation (1/1000) et de repenser la géométrie des pixels afin d'obtenir des détecteurs mieux adaptés au rayonnement incident.Cette thèse a également été l'occasion, et ce de manière indépendante à la polarimétrie, de réfléchir à l'intégration de la spectroscopie au sein du plan focal. Pour cela, nous nous sommes orientés vers de l'interférométrie de type Fabry Pérot (FP). Un FP dans un faisceau collimaté présente l'avantage d'être très facilement compatible avec l'imagerie. Toutefois, nous avons choisi d'intégrer le spectromètre au plus près du détecteur (et donc dans le faisceau convergent). Nous avons également initié le développement de FP tout silicium (Si) à haute résistivité afin de réduire les pertes dûes aux miroirs métalliques, conventionnellement utilisés dans nos gammes de longueurs d'onde. Afin d'améliorer les performances spectrales du FP, les miroirs sont fabriqués via un empilement de couches de silicium interposés de vide tels des miroirs de Bragg. Cela permet d'augmenter rapidement le coefficient de réflexion des miroirs sans toutefois en augmenter trop la complexité: une finesse de 215 est, par exemple, attendue à 320 µm pour un FP utilisant des miroirs Si/vide/Si. Ensuite, nous avons étudié le couplage détecteur/FP qui se voit renforcé par la résonance des deux cavités optiques formées par le système complet. Enfin, des calculs ont montré qu'un FP avec une finesse raisonnable (150) mis dans le plan focal ne dégrade que très peu l'imagerie et la spectroscopie.A la fin de cette thèse, plusieurs étalons FP ont été réalisés et ont déjà démontré des propriétés intéressantes: une résolution spectrale de 180 a notamment été obtenue. En plus de cela, les mesures ont montré que le silicium avait une absorption négligeable à 77 KThis thesis assesses the potential of gathering several instrumental functions into a bolometer array for sub-millimetric astronomical observations. This possibility is now conceivable thanks to the recent progress made in micro-technologies.First, we optimized the design of polarimetric pixels invented for the B-BOP instrument of the future space observatory SPICA. This work enabled the quantification of the cross-polarization (1/1000) and to rethink the geometry of the pixels in order to obtain detectors better matched to incident radiation.This thesis has also been an opportunity to deal with the integration of spectroscopy within the focal plane, independently from the polarimetry aspect. We accordingly focused on Fabry-Pérot (FP) interferometry, as an FP in a collimated beam can well-suited for imaging. Nonetheless, we chose to integrate the spectrometer closer to the detector (and thus in the convergent beam). We also initiated the development of an FP made from high-resistivity silicon in order to lower the losses due to metallic mirrors, generally used in this range of wavelengths. With the objective to enhance the spectral capabilities of the FP, mirrors are built as a stack of silicon layers, separated by vacuum (Bragg mirrors). This increases the reflectivity of the mirrors while keeping the complexity to a reasonable level : a finesse of 215, for instance, is expected at 320 µm for a FP using Si/vacuum/Si mirrors. As a next step, we studied the detector/FP coupling which is enhanced by the resonance of two optical cavities formed by the whole system. Eventually, calculations showed that an FP with a moderate finesse (150) put in the focal plane barely deteriorates imaging or spectroscopy.By the end of this thesis, several FP etalons have been built and have already demonstrated favorable properties: we obtained a spectral resolution of 180. Moreover, measurements showed that silicon has a negligible absorption at a temperature of 77 K
13
Saridakis, Voula. "Scientific controversy and the new astronomy: the intellectual and social contexts of the Hevelius-Hooke dispute". Thesis, Virginia Tech, 1993. http://hdl.handle.net/10919/45615.
Resumo:
During the seventeenth century, science, and especially astronomy, underwent significant changes in which the emphasis on instrumentation shifted from a more qualitative approach to precise quantitative measurement. These changes were further encouraged by the formation of scientific societies, such as the Royal Society in London and the Royal Academy of Sciences in Paris, where members worked together as a collective to validate knowledge. Because members could freely dissent within the community, a prescribed behavior for participants in disputes was proposed, although seldom followed. Furthermore, disputes were not influenced by intellectual issues alone -- social factors also guided and influenced the course of controversies.
This study is an analysis of one scientific controversy in which the participants deviated from the prescribed code of behavior in scientific disputes, and, although the controversy was guided primarily by social factors, intellectual factors ultimately determined its outcome. In the Introduction, I discuss two sociological theses (Merton, Shapin and Schaffer) which are relevant to scientific controversies. In Chapter 1, I describe the changing nature of astronomy and instrumentation in the seventeenth century with special emphasis on micrometers and telescopic sights. In Chapter 2, I explore the nature of scientific controversy vis-à-vis the Royal Society, and two particular controversies which did not deviate from the expected rules of behavior. A descriptive account of the Hevelius-Hooke dispute follows in Chapter 3, and in Chapter 4, I provide concluding remarks on the dispute. Finally, in the Conclusion, I discuss the intellectual and social contexts of the Hevelius-Hooke dispute.Master of Science
14
Saridakis, Voula. "Scientific controversy and the new astronomy : the intellectural and social contexts of the Hevelius-Hooke dispute /". This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-11102009-020225/.
15
Copley, Charles Judd. "Temperature dependence of the HartRAO pointing model". Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1005277.
Resumo:
This thesis investigates control aspects of the Hartebeeshoek Radio Astronomy Observatory (HartRAO) antenna. The installation of a new 22 GHz receiver has required the pointing accuracy to be improved to less than 4 mdeg. The effect of thermal conditions on the the HartRAO antenna pointing offset is investigated using a variety of modelling techniques including simple geometric modelling, neural networks and Principal Component Analysis (PCA). Convincing results were obtained for the Declination pointing offset, where applying certain model predictions to observations resulted in an improvement in Declination pointing offset from 5.5 mdeg to 3.2 mdeg (≈50%). The Right Ascension pointing model was considerably less convincing with an improvement of approximately from 5.5 mdeg to 4.5 mdeg (≈20%) in the Right Ascension pointing offset. The Declination pointing offset can be modelled sufficiently well to reduce the pointing offset to less than 4 mdeg, however further investigation of the underlying causes is required for the Right Ascension pointing offset.
16
Carter, DB. "Automation of the acquisition system of the 1,9 m telescope for the charge coupled device (CCD) camera". Thesis, Cape Technikon, 1988. http://hdl.handle.net/20.500.11838/1075.
Resumo:
Thesis (Master Diploma (Electrical Engineering))-- Cape Technikon, Cape Town, 1988This thesis describes the control system developed to improve the efficiency of star acquisition on a ground-based optical telescope. "Star Acquisition" refers to the process of identifying the star of interest in a field of stars and centering it on the optical axis of the telescope , as well as setting an autoguider detector on a suitable star so the autoguider can improve the tracking performance of the telescope. Efficiency is improved by making all functions remote controlled , so the astronomer does not have to move between the control room and the telescope to operate the instrument.
17
Youthed, Andrew David. "Designing and implementing a new pulsar timer for the Hartebeesthoek Radio Astronomy Observatory". Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1005243.
Resumo:
This thesis outlines the design and implementation of a single channel, dual polarization pulsar timing instrument for the Hartebeesthoek Radio Astronomy Observatory (HartRAO). The new timer is designed to be an improved, temporary replacement for the existing device which has been in operation for over 20 years. The existing device is no longer reliable and is di±cult to maintain. The new pulsar timer is designed to provide improved functional- ity, higher sampling speed, greater pulse resolution, more °exibility and easier maintenance over the existing device. The new device is also designed to keeping changes to the observation system to a minimum until a full de-dispersion timer can be implemented at theobservatory. The design makes use of an 8-bit Reduced Instruction Set Computer (RISC) micro-processor with external Random Access Memory (RAM). The instrument includes an IEEE-488 subsystem for interfacing the pulsar timer to the observation computer system. The microcontroller software is written in assembler code to ensure optimal loop execution speed and deterministic code execution for the system. The design path is discussed and problems encountered during the design process are highlighted. Final testing of the new instrument indicates an improvement in the sam- pling rate of 13.6 times and a significant reduction in 60Hz interference over the existing instrument.
18
Laag, Edward Aric. "Observations of starburst galaxies science and supporting technology /". Diss., [Riverside, Calif.] : University of California, Riverside, 2009. http://proquest.umi.com/pqdweb?index=0&did=1957320791&SrchMode=2&sid=2&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1268854875&clientId=48051.
Resumo:
Thesis (Ph. D.)--University of California, Riverside, 2009.Includes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed March 16, 2010). Includes bibliographical references. Also issued in print.
19
Pollard, Lloyd Wayne 1936. "Design of a flexure mount for optics in dynamic and cryogenic environments". Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276741.
Resumo:
The design of the flexure mount recently submitted to NASA Ames for the structural support of the primary mirror of the Space Infrared Telescope Facility (SIRTF) is presented. The flexure system must passively accommodate the differential thermal contraction between the glass mirror and the aluminum structure of the telescope during cryogenic cooldown. Further, it must support the one meter diameter, 116 kilogram (258 pound) primary mirror during a severe launch to orbit. Procedures used to establish the required radial compliance using computer programs NASTRAN and FRINGE are discussed. The parametric design program developed to study early concepts is presented. Methods of combining modal responses resulting from a displacement response spectrum analysis are discussed, and a combination scheme called MRSS, Modified Root of Sum of Squares, is presented. Modal combination schemes using MRSS, SRSS, and ABS are compared to the results of a Modal Frequency Response analysis.
20
Braun, Stephanie Eva. ""Strange machines" from the West: European curiosities at the Qing imperial courts, 1644-1796". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B4598752X.
21
Molina, Moreno Rocío Gabriela. "Design of optical systems for W-Band astronomical heterodyne cameras". Tesis, Universidad de Chile, 2017. http://repositorio.uchile.cl/handle/2250/145310.
Resumo:
Magíster en Ciencias de la Ingeniería, Mención Eléctrica.
Ingeniera Civil EléctricaThe new generation of telescopes that will be installed in the world and particularly in Chile is focused on the search of high-impact scientific objectives. For this, the technology used must be cutting edge, in order to achieve a better performance than currently achieved. This challenge falls into the hands of engineering and this thesis is developed in that context. The general objective is to develop intermediate optical systems to allow the existence of heterodyne cameras in the range of 85 - 115 GHz (extended W band). For this, two sub-projects are developed. In the first one, we work with the original design of the 1.2-m SMWT telescope that is currently in the National Astronomical Observatory in Cerro Calán. We study the feasibility of having a heterodyne camera without the need to add extra optical elements. For the second project, the parameters of the 12-m ALMA antenna are used. An intermediate optical system consisting of a Gaussian Beam Telescope is designed. We seek to adapt the optics of the antenna with a heterodyne receiver of 7 pixels. This design is applicable to a future ALMA upgrade or to the LLAMA project, which is under development. In both projects, we work with mathematical models developed in Matlab and based on the quasi-optical model. Subsequently, fine-tuning the models is performed with simulation software. Performance parameters such as aperture efficiency, noise temperature, beam truncation, cross-polar component and surface accuracy are taken into account for the design. We find an appropriate beam position and waist for the SMWT 7-pixel heterodyne receiver. The normalized efficiency of the lateral beams is 92.9% with respect to the central beam. A 23.6-mm spacing between beams with a 6.8-mm waist in the Cassegrain focal plane is required. No additional optics are necessary. For the design in a 12-m antenna, a 58.6-mm spacing is obtained in the Cassegrain focal plane, a beam waist of 16.8 mm and a normalized efficiency of 96.9% for the central frequency (100 GHz). The design for both, ALMA and LLAMA, consists of a Gaussian Beam Telescope using two ellipsoidal mirrors and compacted by the use of flat mirrors. The magnification in each case is different due to the space constraints particular to each. This implies that the waist of the beam in the vacuum window is different.
Este trabajo ha sido parcialmente financiado por FONDECYT a través del Proyecto 11151022
22
Lee, David. "New techniques in astronomical spectroscopy for 8-m telescopes". Thesis, Durham University, 1998. http://etheses.dur.ac.uk/4847/.
Resumo:
The purpose of this thesis is to investigate new instrument technology to enhance the capabilities of 8-m telescopes. This thesis first describes the theory, design, construction, and testing of an immersed grating. Immersed gratings can be used to provide R≥ 10(^4) with a multi-object and/or integral field spectrograph on an 8-m telescope. Immersed gratings allow high resolution to be achieved whilst maintaining the required pupil size at a level similar to that on 4-m telescopes. This thesis describes laboratory tests which verify that immersed gratings provide high resolution. The throughput penalty in using an immersed grating is shown to be small with losses due to air-glass reflections, which can be eliminated with antireflection coatings, and metal-dielectric losses. This work demonstrates that immersed gratings provide a good method to reach R=10(^4) (and above) with a multi-aperture spectrograph on an 8-m telescope. The second part of this thesis describes the construction of a microlens-fibre based integral field unit (IFU): the SMIRFS-IFU. This instrument provides a unique J and H-band integral field capability for use with the CGS4 spectrograph at UKIRT. The optical design, assembly, laboratory testing, and telescope commissioning of the SMIRFS-IFU are described. The microlens arrays for use with SMIRFS-IFU were tested in detail and found to provide excellent image quality but with some scattered light. The assembly of the SMIRFS-IFU was achieved with high precision. The overall performance of the SMIRFS-IFU was found to be high and close to theoretical expectations. This instrument demonstrates that the technology of microlenses linked to fibres does provide a means of constructing high performance (i.e. high throughput, high spatial and spectral resolution) IFUs. Integral field spectroscopy is even more important for 8-m telescopes to take advantage of their enormous fight gathering power. The SMIRFS-IFU is an important upgrade to CGS4 to perform high spatial resolution integral field spectroscopy.
23
Staubermann, Klaus. "Astronomers at work : a study of the replicability of 19th century astronomical practice /". Frankfurt, M. : Deutsch, 1998. http://d-nb.info/985198958/04.
24
Mate, Sujay. "Développement d'un simulateur du ciel pour les instruments à grand champ de vue X-gamma en orbite terrestre basse : application à l'évaluation des performances du spectro-imageur SVOM-ECLAIRs". Thesis, Toulouse 3, 2021. http://www.theses.fr/2021TOU30031.
Resumo:
Les sursauts gamma (Gamma-Ray Bursts ou GRBs) sont les explosions les plus lumineuses de l'univers. On les observe sous la forme de bouffées de rayons X/ƴ (d'une durée de quelques millisecondes à quelques dizaines de secondes) suivies d'une émission rémanente (généralement à de plus grandes longueurs d'onde). Ils résultent soit de la fusion de deux objets compacts (une paire d'étoiles à neutrons ou une étoile à neutrons et un trou noir), soit de l'effondrement du noyau d'une étoile massive (>15 masse solaire). Les GRBs sont d'excellents candidats pour étudier la physique aux énergies et densités extrêmes et un outil astrophysique pour sonder l'histoire de l'univers car ils sont observés à tous les âges de celui-ci. La mission spatiale Sino-Française SVOM (lancement prévu en juin 2022) a pour objectif la détection et l'étude des GRBs à l'aide d'instruments spatiaux et terrestres dédiés afin d'obtenir une couverture multi-longueurs d'onde. Le principal instrument à bord du satellite SVOM est ECLAIRs, un imageur à masque codé à grand champ de vue (~2 sr) fonctionnant dans la bande d'énergie de 4 à 150 keV. ECLAIRs détectera et localisera les GRBs (ainsi que d'autres sources transitoires à hautes énergies) en temps quasi réel grâce à son " trigger " embarqué. Le bruit de fond d'ECLAIRs est élevé et variable en raison du grand champ de vue et de la stratégie de pointage de SVOM qui amène la Terre à transiter dans le champ de vue. Une nouvelle méthode (appelée "Particle Interaction Recycling Approach" ou PIRA en anglais), basée sur des simulations de Monte-Carlo (GEANT4), a été développée pour estimer précisément et rapidement le bruit de fond variable. Les simulations du bruit de fond sont complétées avec des sources X et des sursauts gamma afin de générer des scénarios d'observation complets. Le bruit de fond variable d'ECLAIRs pose des problèmes pour la détection des GRBs et affecte la sensibilité de l'instrument. Nous avons évalué les performances du "trigger" embarqué, notamment l'impact du bruit de fond sur la détection des sources transitoires et sa sensibilité aux caractéristiques des GRBs (durée, profil temporel, forme spectrale, position dans le champ de vue). ECLAIRs enverra au sol tous les photons détectés. De plus, la disponibilité d'une plus grande puissance de calcul et une meilleure connaissance du contexte (par exemple, les variations du bruit de fond, les sources dans le champ de vue, etc.) au sol, nous ont conduits à développer un "trigger" sol pour surmonter les difficultés rencontrées par le "trigger" embarqué. Ainsi, nous proposons un algorithme basé sur des transformées en ondelettes pour détecter les GRBs dans le cadre du "trigger" sol. Les travaux de cette thèse, à savoir le développement de PIRA, l'évaluation des performances et le développement d'un nouvel algorithme de détection de sursauts, fournissent une base solide pour construire un "trigger" sol efficace, qui complétera le "trigger" embarqué et améliorera les performances globales de la mission SVOMGamma-Ray Bursts (GRBs) are the most luminous explosions in the universe. They are observed as bright flashes of gamma/X-rays (lasting a few milliseconds to a few tens of seconds) followed by an "afterglow" emission (usually at longer wavelengths). They are produced either due to the merger of two compact objects (a pair of neutron stars or a neutron star and a black hole) or due to the core collapse of a massive star (> 15 solar mass). GRBs are excellent candidates to study physics at extreme energies and densities. They also constitute important astrophysical tools to probe the history of the universe as they are observed at all epochs. The upcoming (June 2022) Sino-French mission SVOM (Space-based multi-band astronomical Variable Objects Monitor) aims to detect and study GRBs using dedicated space and ground based instruments to obtain multi-wavelength coverage. The primary instrument onboard SVOM spacecraft is ECLAIRs, a wide-field (~ 2 sr) coded-mask imager sensitive in the 4 - 150 keV energy range. ECLAIRs will detect and localise GRBs (and other high energy transients) in near real time using an onboard trigger. ECLAIRs will encounter a high and variable background due to the wide field-of-view (FoV) and the pointing strategy of SVOM which makes the Earth transit through the FoV. A new method (called Particle Interaction Recycling Approach or PIRA), based on Monte-Carlo simulations (GEANT4), was developed to estimate the variable background accurately and rapidly. The simulations of the background are complemented with simulations of X-ray sources and gamma-ray bursts to generate complete observation scenarios. The variable background of ECLAIRs poses challenges to detect GRBs and affects the sensitivity of the instrument. We use the simulated data to evaluate the performance of the onboard trigger, in particular, the impact of the variable background and its sensitivity to the GRB characteristics (duration, temporal profile, spectral shape,position in the FoV). ECLAIRs will send all detected photons to the ground. In addition, the availability of a larger computational power and the better knowledge of the context (e.g. background variations, sources in the FoV, etc.) on the ground motivates us to develop an "offline trigger" to overcome the challenges faced by the onboard trigger. An algorithm based on wavelet transforms is proposed to detect GRBs as part of the offline trigger. The work in this thesis, i.e. the development of PIRA, instrument's performance evaluation and development of a trigger method, provides a sound basis to build an effective offline trigger that will complement the onboard trigger and improve the overall performance of the SVOM mission
25
Welsh, Frederick V. "Scientific application of the Santa Barbara instrument group self-guided spectrograph". Virtual Press, 2004. http://liblink.bsu.edu/uhtbin/catkey/1295146.
Resumo:
The Santa Barbara Instrument Group self-guided spectrograph is aimed primarily at the advanced amateur astronomer. This study has determined that this instrument is capable of being used for scientific research. A comparison lamp box was built to be used in conjunction with the spectrograph. A test was conducted to determine the accuracy of the grating positioning micrometer. A chart was created to allow the conversion of the micrometer readings to correlate with the position of the low-dispersion grating. To determine the scientific applicability of the spectrograph, it was used to: (1) measure the expansion rate of Nova Sagittarius 2004, (2) look for a 13.9-minute periodicity in the width and position of the H-alpha line of the binary star system X Persei, and (3) to measure the Doppler shift of X Persei. The instrument proved to be capable of being used to determine radial velocities and Doppler shifts.Department of Physics and Astronomy
26
Berger, Jean-Philippe. "Interférométrie et formation stellaire : Perspectives pour une instrumentation en optique intégrée". Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10213.
Resumo:
Je présente les premières observations infrarouges des étoile FU Ori et AB Aur obtenues avec les interféromètres longue base IOTA(Umass, SAO) et PTI (JPL/NASA). Ces deux étoiles sont des prototypes des étoiles pré-séquence principale de faible masse (FU Ori) et de masse intermédiaire (AB Aur). Les deux sources sont résolues avec une résolution de l'ordre de l'unité astronomique. Divers scénarios sont envisagés. Les observations sont tout à fait compatibles avec la présence d'un disque d'accrétion autour de FU Ori. Afin d'améliorer les performances scientifiques et de diminuer la complexité des instruments interférométriques, je propose d'utiliser l'optique intégrée planaire pour la fonction de recombinaison. Je présente les résultats des caractérisations d'un recombinateur réalisé dans une technologie d'échanges d'ions sur substrat de verre. Cette "puce optique" comporte deux entrées et trois sorties : une voie interférométrique et deux voies de calibration photométrique. Elle est optimisée pour la bande H et assure le maintien de la polarisation. Les caractérisations montrent des pertes photoniques réduites, un contraste laser de ~ 90% et un contraste en bande large maximum de ~ 30%. Les origines de cette chute de contraste sont identifiées et des méthodes de caractérisation plus poussées sont proposées. Plusieurs perspectives de recombinaison multi-télescopes se dégagent à la suite de ce travail. Enfin, à la lumière de ces résultats, je présente le concept d'un instrument recombinateur portable baptisé IONIC, qui pourrait être le précurseur de l'instrumentation de deuxième génération des interféromètres monomodes au sol et dans l'espace. Ses principaux atouts sont la précision de mesures sur les visibilités, la compacité et la stabilité.
27
Marques, Leonardo Soares. "Apropriação e domínio de instrumentos para o ensino de Astronomia". Universidade Federal de Minas Gerais, 2010. http://hdl.handle.net/1843/FAEC-8GGMK6.
Resumo:
ABSTRACT The present research sought information on how teachers appropriate and create their dominion over the instruments of the KIT FOR THE TEACHING OF ASTRONOMY (KITPEA). The subjects of this study were teachers who attended the course on astronomy education offered by the Continuing Education Project (FoCo) at the Center for Teaching Science and Mathematics (CECIMIG), Faculty of Education, Federal University of Minas Gerais (FAE / UFMG ). We have collected data through a questionnaire and an interview with these teachers. We structured the data analysis with the help of Activity Theory and the Theory of Mediated Action. We have applied a interpretive discourse analysis of the teachers statements using as the analytical device the constitutive elements of the activity system and the concepts of appropriation and dominion. In this research appropriation means "taking something from other and making it your own" and the dominion means "knowing how to use a cultural tool." We consider as appropriate instruments, those which teachers reported some usind during a learning activity. The dominion, by its turn, we interpreted as the way teachers described the adaptations of the instruments in their activities, and how they have overcome the difficulties encountered. From our analysis we identify other ways for teachers to continue the process of training in the field of astronomy education such as visits to observatories, participation in study groups, reading periodics. Among the 11 subjects who participated in the survey, it was possible to interpret clearly the field in seven narratives. In summary, we recommend that teachers initially have the opportunity to learn the tools of KITPEA,then adapts them to the development of activities with their students. We also recommend the development of activities involving more subjects of the school community, so they can help each other overcome the difficulties which usually appear during the use of instruments KITPEA.RESUMO Esta pesquisa buscou indicações sobre a maneira como os professores se apropriam e criam seus domínios sobre os instrumentos do KIT PARA O ENSINO DE ASTRONOMIA (KITPEA). Os sujeitos dessa pesquisa foram professores que participaram do curso de especialização em ensino de astronomia oferecido pelo Projeto de Formação Continuada (Foco) no Centro de Ensino de Ciências e Matemática (CECIMIG) da Faculdade de Educação da Universidade Federal de Minas Gerais (FaE/UFMG). Coletamos as informações por meio de um questionário e de uma entrevista, aplicados a esses professores. Estruturamos a análise dessas informações com a ajuda da Teoria da Atividade e da Teoria da Ação Mediada. Aplicamos uma análise de discurso interpretativa das falas dos professores usando como dispositivo analítico os elementos constituintes do sistema de atividade e os conceitos de apropriação e domínio. Nessa pesquisa, apropriação significa tomar algo do outro e torná-lo seu próprio e domínio significa saber usar uma ferramenta cultural. Consideramos como instrumentos apropriados aqueles que os professores relatam terem feito algum uso durante uma atividade de ensino. Já o domínio, interpretamos como a maneira segundo a qual os professores descreveram as adaptações dos instrumentos em suas atividades, e a forma de superarem as dificuldades encontradas. A partir dessas análises identificamos outras formas de os professores darem continuidade ao seu processo de formação no campo do ensino de astronomia tais como: visitas a observatórios, participação em grupos de estudos, leitura de revistas. Dentre os 11 sujeitos que participaram da pesquisa, foi possível interpretarmos com clareza o domínio em 7 narrativas. Em síntese, recomendamos que os professores inicialmente tenham a oportunidade de aprender com os instrumentos do KITPEA, para depois adapta-los para o desenvolvimento de atividades com seus estudantes. Recomendamos também o desenvolvimento de atividades com a participação de mais sujeitos da comunidade escolar, para que eles possam ajudar uns aos outros a superarem as dificuldades que normalmente aparecem durante o uso dos instrumentos do KITPEA.
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Soares, Leonardo Marques. "Apropriação e domínio de instrumentos para o ensino de astronomia". Universidade Federal de Minas Gerais, 2010. http://hdl.handle.net/1843/BUDB-8C6PET.
Resumo:
The present research sought information on how teachers appropriate and create their dominion over the instruments of the KIT FOR THE TEACHING OF ASTRONOMY (KITPEA). The subjects of this study were teachers who attended the course on astronomy education offered by
the Continuing Education Project (FoCo) at the Center for Teaching Science and Mathematics (CECIMIG), Faculty of Education, Federal University of Minas Gerais (FAE / UFMG ). We have collected data through a questionnaire and an interview with these teachers. We structured the
data analysis with the help of Activity Theory and the Theory of Mediated Action. We have applied a interpretive discourse analysis of the teachers statements using as the analytical device the constitutive elements of the activity system and the concepts of appropriation and dominion.
In this research appropriation means "taking something from other and making it your own" and the dominion means "knowing how to use a cultural tool." We consider as appropriate instruments, those which teachers reported some usind during a learning activity. The dominion,
by its turn, we interpreted as the way teachers described the adaptations of the instruments in their activities, and how they have overcome the difficulties encountered. From our analysis we identify other ways for teachers to continue the process of training in the field of astronomy
education such as visits to observatories, participation in study groups, reading periodics. Among the 11 subjects who participated in the survey, it was possible to interpret clearly the field in seven narratives. In summary, we recommend that teachers initially have the opportunity to learn the tools of KITPEA, then adapts them to the development of activities with their students. We also recommend the development of activities involving more subjects of the school community,
so they can help each other overcome the difficulties which usually appear during the use of instruments KITPEA.Esta pesquisa buscou indicações sobre a maneira como os professores se apropriam e criam seus domínios sobre os instrumentos do KIT PARA O ENSINO DE ASTRONOMIA (KITPEA). Os sujeitos dessa pesquisa foram professores que participaram do curso de especialização em ensino de astronomia oferecido pelo Projeto de Formação Continuada (Foco) no Centro de Ensino de Ciências e Matemática (CECIMIG) da Faculdade de Educação da Universidade Federal de Minas Gerais (FaE/UFMG). Coletamos as informações por meio de um questionário e de uma entrevista, aplicados a esses professores. Estruturamos a análise dessas informações com a ajuda da Teoria da Atividade e da Teoria da Ação Mediada. Aplicamos uma análise de discurso interpretativa das falas dos professores usando como dispositivo analítico os elementos constituintes do sistema de atividade e os conceitos de apropriação e domínio. Nessa pesquisa, apropriação significa tomar algo do outro e torná-lo seu próprio e domínio significa saber usar uma ferramenta cultural. Consideramos como instrumentos apropriados aqueles que os professores relatam terem feito algum uso durante uma atividade de ensino. Já o domínio, interpretamos como a maneira segundo a qual os professores descreveram as adaptações dos instrumentos em suas atividades, e a forma de superarem as dificuldades encontradas. A partir dessas análises identificamos outras formas de os professores darem continuidade ao seu processo de formação no campo do ensino de astronomia tais como: visitas a observatórios, participação em grupos de estudos, leitura de revistas. Dentre os 11 sujeitos que participaram da pesquisa, foi possível interpretarmos com clareza o domínio em 7 narrativas. Em síntese, recomendamos que os professores inicialmente tenham a oportunidade de aprender com os instrumentos do KITPEA, para depois adapta-los para o desenvolvimento de atividades com seus estudantes. Recomendamos também o desenvolvimento de atividades com a participação de mais sujeitos da comunidade escolar, para que eles possam ajudar uns aos outros a superarem as dificuldades que normalmente aparecem durante o uso dos instrumentos do KITPEA.
29
Patti, Mauro <1989>. "MAORY: wavefront sensor prototype and instrument optical design". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amsdottorato.unibo.it/8534/1/Mauro_Patti.pdf.
Resumo:
MAORY will be the multi-conjugate adaptive optics module for the ELT first light. Its main goal is to feed the high-resolution NIR imager and spectrograph MICADO.
The present Thesis address the MAORY system at the level of optical design and analysis.
MAORY is a complex science projects whose stakeholder is the scientific community. Its requirements are driven by the science cases which request high resolution and astrometric accuracy.
In an ideal world without atmospheric turbulence, MAORY optics must deliver diffraction-limited images with very low optical distortions.
The tolerance process is one of the most important step in the instrument design since it is intended to ensure that MAORY requested performances are satisfied when the final assembled instrument is operative.
The baseline is to operate wavefront sensing using six sodium Laser Guide Stars and three Natural Guide Stars to solve intrinsic limitations of artificial sources and to mitigate the impact of the sodium layer structure and variability.
The implementation of a laboratory Prototype for Laser Guide Star wavefront sensor at the beginning of the phase study of MAORY has been indispensable to consolidate the choice of the baseline of wavefront sensing technique.
The first part of this Thesis describes the results obtained with the Prototype for Laser Guide Star wavefront sensor under different working conditions.
The second part describes the logic behind the tolerance analysis at the level of MAORY optical design starting from definition of quantitative figures of merit for requirements and ending with estimation of MAORY performances perturbed by opto-mechanical tolerances.
The sensitivity analysis on opto-mechanical tolerance of MAORY is also a crucial step to plan the alignment concept that concludes the arguments addressed by this Thesis.
30
Perez, Everton Piza [UNESP]. "Caixa experimentoteca: uma proposta para o ensino de astronomia". Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/136053.
Resumo:
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000857808.pdf: 1904764 bytes, checksum: d01be9c9d01ac82af8b73da25d03b4b6 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A visão de um céu estrelado numa noite límpida tem fascinado a Humanidade desde os tempos pré-históricos. O homem começou a fazer ciência a partir do momento em que se perguntou o que eram as estrelas e porque estavam ali, desenhando a aparência do céu e tentando predizer os fenômenos celestes. A partir do momento em que Galileu apontou sua luneta para o céu, iniciou-se uma estreita relação entre a evolução dos instrumentos astronômicos, a tecnologia, a história e a ciência. Seu ato deu suporte às ideias de Nicolau Copérnico, que nos tirou da idade das trevas e nos guiou ao Renascimento, culminando com a teoria da Gravitação Universal de Newton. Atualmente, muitas pesquisas têm sido realizadas dentro da temática da melhoria do ensino de Ciências. No entanto, a História da Ciência ensinada nos Ensinos Fundamental e Médio, e até no superior, apresenta problemas, como erros factuais e conceituais. A fim de proporcionar melhor compreensão do fenômeno, este trabalho pretende-se explorar a utilização de uma caixa de experiências através da utilização de um material didático para a Astronomia, chamado de Caixa Experimentoteca, relacionado com a teoria da Astronomia que é ensinada no Ensino Médio
The sight of a starry sky on a clear night has fascinated humanity since prehistoric times. The man began to do sciense from the moment we wondered what were the stars and why they were there, drawing the appearance of the sky and trying to predict the celestial phenomena. From the time when Galileo pointed his telescope to the sky, began a close relationship between the evolution of astronomical instruments, technology, history and science. His act gave guided us to the Renaissance, culminating in the theory of universal gravitation Newton. Currently, many researches have been conducted within the theme of improving the teaching of science. However, the History of Science taught in Elementary and High School, and even on top, presentes problems as factual and conceptual errors. In order to provide better understanding of the phenomenon, this study intends to explore the use of a box of experiences through the use of educational material for Astronomy, called Experimentoteca case, related of astronomy that is taught in high school
31
Perez, Everton Piza. "Caixa experimentoteca : uma proposta para o ensino de astronomia /". Presidente Prudente, 2015. http://hdl.handle.net/11449/136053.
Resumo:
Orientador: Angel Fidel Vilche PeñaBanca: Celso Xavier Cardoso
Banca: Agda Eunice de Souza Albas
Banca: Renivaldo José dos Santos
Resumo: A visão de um céu estrelado numa noite límpida tem fascinado a Humanidade desde os tempos pré-históricos. O homem começou a "fazer ciência" a partir do momento em que se perguntou o que eram as estrelas e porque estavam ali, desenhando a aparência do céu e tentando predizer os fenômenos celestes. A partir do momento em que Galileu apontou sua luneta para o céu, iniciou-se uma estreita relação entre a evolução dos instrumentos astronômicos, a tecnologia, a história e a ciência. Seu ato deu suporte às ideias de Nicolau Copérnico, que nos tirou da idade das trevas e nos guiou ao Renascimento, culminando com a teoria da Gravitação Universal de Newton. Atualmente, muitas pesquisas têm sido realizadas dentro da temática da melhoria do ensino de Ciências. No entanto, a História da Ciência ensinada nos Ensinos Fundamental e Médio, e até no superior, apresenta problemas, como erros factuais e conceituais. A fim de proporcionar melhor compreensão do fenômeno, este trabalho pretende-se explorar a utilização de uma caixa de experiências através da utilização de um material didático para a Astronomia, chamado de Caixa Experimentoteca, relacionado com a teoria da Astronomia que é ensinada no Ensino Médio
Abstract: The sight of a starry sky on a clear night has fascinated humanity since prehistoric times. The man began to "do sciense" from the moment we wondered what were the stars and why they were there, drawing the appearance of the sky and trying to predict the celestial phenomena. From the time when Galileo pointed his telescope to the sky, began a close relationship between the evolution of astronomical instruments, technology, history and science. His act gave guided us to the Renaissance, culminating in the theory of universal gravitation Newton. Currently, many researches have been conducted within the theme of improving the teaching of science. However, the History of Science taught in Elementary and High School, and even on top, presentes problems as factual and conceptual errors. In order to provide better understanding of the phenomenon, this study intends to explore the use of a box of experiences through the use of educational material for Astronomy, called Experimentoteca case, related of astronomy that is taught in high school
Mestre
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Silva, Denilton Machado da. "A prática da astronomia em aulas no formato de oficinas e suas aplicações na modalidade de ensino EAD /". Presidente Prudente, 2016. http://hdl.handle.net/11449/149985.
Resumo:
Orientador: Cláudio Luiz CarvalhoBanca: Fernanda Catia Bozelli
Banca: Hermes Adolfo de Aquino
Resumo: De acordo com pesquisas em ensino de ciências, nos últimos tempos, os alunos de forma geral, não compreendem e não desenvolvem as tarefas sobre os conceitos básicos de ciências, como por exemplo, relacionar um tema de Física com os acontecimentos rotineiros do dia a dia, assim como relacioná-lo com a Química ou Geografia. Uma possível hipótese está no fato de que o ambiente escolar frequentado pelos alunos, atualmente, está desconexo com os interesses e curiosidades que eles possuem em aprender. Estes interesses estão ligados apenas a conceitos imediatistas. Esta geração de alunos que está se moldando é conhecida como "geração tecnológica". As simples experimentações em si realizadas em salas de aulas não refletem no real aprendizado para que os alunos desenvolvam competências e habilidades na elaboração de saberes científico. Os conteúdos são apenas direcionados para cumprir currículos em espaços de tempo cada vez mais reduzidos. Pela fundamentação teórica de David Ausubel, que relaciona a questão de materiais representativos e significativos no processo de ensino aprendizagem, foi proposta, nesta pesquisa, a discussão dos conceitos de Astronomia, em formatos de oficinas, na qual os alunos foram incentivados a criar o próprio conhecimento de forma construtivista por meio da metodologia mediadora na relação com os outros saberes como a Matemática, Geografia, História, Física incentivando a interdisciplinaridade. Os resultados obtidos nas oficinas foram gravados e transformado... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In agreement of recent science education research, recently, in general, students cannot understand and also can not develop their stuff about basic science concepts, such as make the relationship between Physics and something that happen day-by-day either relation with chemistry or geography. A possible hypothesis can be the fact of the scholar ambient could be disconnected from the interest and curiosities that they should be to learn. These interests are connected just only with immediatist concepts. The students generation that is coming is called "Technological generation". The experiments did in classroom have not been enough to improve their scientific skills. The subjects are just specifically used to fulfill curricula in a short period of time (and this time have been reduced constantly or periodically or frequently). By the theoretical basis of David Ausubel, that related representative and significative materials in the teaching/ learnt process was proposed, in this Project, the discussion of about Astronomy concepts using workshop format, In which students were encouraged to create their own knowledge in a constructivist way through the mediator methodology in relation to other knowledge such as Mathematics, Geography, History, Physics encouraging interdisciplinarity. The results obtained in the workshops were recorded and transformed in media material that it can be shared in web. This material is being used for reference source and studies, providing free access... (Complete abstract click electronic access below)
Mestre
33
Wang, Haobing. "Optical Fibre Characterisation for the new-generation instrument - Hector". Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/29988.
Resumo:
Australia has been the world leader in astrophotonic developments, led by the SAIL/Astralis-USyd labs at The University of Sydney. A new, novel optical fibre imaging device, called a ‘Hexabundle’ was invented by a team in the SAIL/Astralis-USyd labs and was implemented in an integral field spectrograph instrument called ‘SAMI’ on the Anglo-Australian Telescope (AAT). Based on the success of SAMI, an innovative new $7m instrument called Hector has now been built and is currently being commissioned on the AAT. Hector has new upgraded hexabundles, positioners and spectrographs. It will now tackle a survey of 15,000 galaxies to give a sample that will have the statistical power to disentangle, for the first time, the impact of large-scale structure in the universe on the formation of galaxies.
The hexabundles for Hector are larger than for SAMI, with 5 sizes up to 169 optical fibre cores to reach 26 arcsecs on sky, allowing imaging of most of the Hector Galaxy Survey targets out to 2 effective radii. These new hexabundles have regular hexagonal fibre packing to simplify post-processing and maximise the light collection with a higher fill fraction. Hector has 21 new hexabundles. There is significant development involved in these upgraded hexabundles.
This thesis focuses on the characterisation and testing of the fibre system for Hector. In particular the throughput and focal ratio degradation (FRD) characterisation was crucial at all stages of the hexabundle development to guide the improvements in the hexabundle process to achieve hexabundles with optical performance as good as bare single fibres. My work in this thesis has been a fundamental contribution to the build and performance of the Hector fibre system. The instrument is now (mid-2022) beginning the Hector Galaxy Survey which will enable the work of > 70 astronomers.
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Souza, Thauane Lima de. "O uso de v?deo e jogo educativos como instrumento de ensino e divulga??o da Astronomia". Universidade Estadual de Feira de Santana, 2016. http://localhost:8080/tede/handle/tede/465.
Resumo:
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Currently, due to the various technological options, the vast access to information and the demotivation of some students, much is discussed in the literature about the way of teaching so that it becomes diversified and attractive. The teacher / classroom model with traditional teaching has leaved to be the main medium in the teaching-learning process. Faced with this new educational paradigm, the need arises to seek strategies that increase the interest, the motivation and consequently the level of learning of the students. In this sense, we have the ludic forms of teaching, such as the application of didactic games, which are increasingly present in the school environment. From this context, a didactic game, entitled "Space Track" and an educational video called "Unraveling the Universe", was created. The theme is about Planets and Dwarf Planets, Eclipse, Seasons of the Year, General Astronomy and Constellations. In particular, these tools can be used in both formal and non-formal learning environments. In this work the product was applied in five classes of Elementary School and four of the High School of the Col?gio Estadual Ferreira Pinto. The survey of prior knowledge and learning after the implementation of activities was carried out through pre- and post-tests on the above topics.
Atualmente, em virtude das v?rias op??es tecnol?gicas, do vasto acesso ? informa??o e da desmotiva??o de alguns estudantes, muito se discute na literatura sobre a forma de ensino de modo que ela se torne diversificada e atrativa. O modelo professor/sala de aula com o ensino tradicional tem deixado de ser o principal meio no processo de ensino-aprendizagem. Diante desse novo paradigma educacional, surge a necessidade de buscar estrat?gias que aumentem o interesse, a motiva??o e consequentemente o n?vel de aprendizagem dos alunos. Neste sentido, temos as formas l?dicas de ensino, como, por exemplo, a aplica??o de jogos did?ticos, que est?o cada vez mais presentes no ambiente escolar. A partir desse contexto, foi elaborado um jogo did?tico, intitulado ?Trilha Espacial? e um v?deo educativo chamado ?Desvendando o Universo?, cuja tem?tica trata sobre Planetas e Planetas An?es, Eclipse, Esta??es do Ano, Conhecimentos Gerais de Astronomia e Constela??es. Em particular, estas ferramentas podem ser utilizadas em ambientes de ensino formal e n?o formal. Neste trabalho o produto foi aplicado em cinco turmas do Ensino Fundamental e quatro do Ensino M?dio do Col?gio Estadual Ferreira Pinto. A sondagem do conhecimento pr?vio e do aprendizado ap?s a aplica??o das atividades foi realizada por meio de pr? e p?s-testes sobre os temas citados.
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Schmitt, César Eduardo. "O uso da astronomia como instrumento para a introdução ao estudo das radiações eletromagnéticas no ensino médio". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2006. http://hdl.handle.net/10183/7541.
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Este trabalho relata a utilização de tópicos ligados à Astronomia, como motivação educacional, a fim de inserir o estudo das radiações eletromagnéticas com abordagem na Física Moderna e Contemporânea. Em geral, a bibliografia atual disponível trata deste assunto (sob o título “ondas eletromagnéticas”) no capítulo relacionado a “ondas”, dentro da Física Clássica, não abordando assim, conceitos da Física Moderna: dualidade onda partícula, quantização da energia, efeito fotoelétrico, Lei de Planck, etc. O tema foi abordado utilizando atividades práticas: observação do Sol, observação do céu com telescópio, simulação computacional através de applets disponíveis na Internet, atividades de laboratório, sempre partindo de aspectos relacionados à Astronomia. A proposta foi aplicada em uma turma de terceira série de Ensino Médio, do Instituto Estadual de Educação de Sapiranga, cidade do Vale do Rio dos Sinos. Este trabalho foi embasado pela Teoria de Aprendizagem Significativa de Ausubel e de Novak, e pela Teoria de mediação de Vygotsky. A partir dos dados colhidos através de testes comparativos, entrevistas e depoimentos dos alunos, foi possível detectar que eles estiveram motivados para a aprendizagem, sendo que alguns inclusive passaram a interessar-se mais pela disciplina de Física. Ao finalizar a aplicação desta proposta de trabalho, foi criado um CD com textos, simulações e sugestões para aplicações em sala de aula.
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Moura, Pedro Macário de. "Astronomia e o ensino de física e de matemática no Ensino Médio em uma escola pública de Petrolina-PE". reponame:Repositório Institucional da UNIVATES, 2016. http://hdl.handle.net/10737/1721.
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A fim de investigar e colaborar com o ensino e a aprendizagem de Astronomia, de educandos de uma Escola Pública Estadual de Petrolina/PE, foi desenvolvido um Projeto de Intervenção Pedagógica, utilizando os conteúdos de Física – Gravitação Universal e de Matemática – Elipses, aos olhos da História da Astronomia. Os participantes da pesquisa foram alunos do 1° e do 3° ano do Ensino Médio. Os estudantes construíram os seguintes instrumentos: relógio de Sol, Astrolábio, Elipse de Kepler e a deformação do espaço-tempo de Einstein, sob a orientação desse autor. Essa prática ocorreu em cinco encontros. No último, os alunos responderam a um questionário aberto, com 10 questões, elaboradas pelo pesquisador, adaptadas dos livros didáticos adotados pela escola, sob a orientação dos Parâmetros Curriculares Nacionais – PCNS. A análise dos resultados foi embasada em pesquisa qualitativa, utilizando a análise textual por meio de um estudo de campo, do qual emergiram, a posteriori, três categorias: Contribuição docente para a aprendizagem do aluno; Aprendizagem de astronomia com uso de instrumentos astronômicos; Aprendizagem de conteúdos de astronomia. Os resultados revelam que os alunos têm preferência por abordagens como a realizada pelo autor, a qual corroborou para uma melhor compreensão dos conceitos de Gravitação Universal e de Elipses, facilitando assim a aprendizagem dos educandos, em relação aos fenômenos astronômicos. Conforme as respostas dos alunos no questionário, a prática desenvolvida apresentou uma maneira nova e mais eficaz de compreender os conteúdos de Física e de Matemática, melhorando a compreensão para a construção do conhecimento por parte dos educandos.
Con el fin de investigar y colaborar con la enseñanza y aprendizaje de la astronomía a los alumnos de una escuela pública de Petrolina, PE, se ha desarrollado un proyecto de intervención pedagógica, con el contenido del Universal de gravitación y física matemáticas-elipses a los ojos de la historia de la astronomía. Participantes en la investigación fueron estudiantes de 1° y 3° año de secundaria. Los estudiantes construyeron los siguientes instrumentos: reloj de sol, astrolabio, elipse de Kepler y la deformación del espacio-tiempo de Einstein, bajo la dirección del autor. Esta práctica llevó a cabo en cinco encuentros, los últimos estudiantes respondieron un cuestionario abierto que contiene 10 preguntas elaborados por los libros del investigador adaptado utilizados en la escuela, utilizando la metodología del plan de estudios nacional parámetros PCNS. El análisis de los resultados llevó a cabo a través de la investigación cualitativa, usando el análisis textual por medio de un estudio de campo. A que surgió a posteriori tres categorías: contribución de la enseñanza al aprendizaje; Astronomía de aprendizaje con el uso de instrumentos astronómicos y el aprendizaje de contenidos de Astronomía. Los resultados muestran que los estudiantes tienen preferencia por enfoques como el autor, porque corrobora a diseñar mejor los conceptos de gravitación Universal y elipses, a facilitar el aprendizaje de los estudiantes ante los fenómenos astronómicos. Una vez, los estudiantes en sus respuestas en el cuestionario de la práctica desarrollada, presenten forma nueva y más eficaz, para comprender los contenidos de física y matemáticas, mejorar la comprensión para la construcción del conocimiento por parte de los alumnos.
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Daigle, Olivier. "Spectro-imagerie optique à faible flux et comparaison de la cinématique Hα et HI d'un échantillon de galaxies proches". Aix-Marseille 1, 2010. http://www.theses.fr/2010AIX10141.
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Un nouveau contrôleur de EMCCD (Electron multiplying Charge Coupled Device) est présenté. Il permet de diminuer significativement le bruit qui domine lorsque la puce EMCCD est utilisé pour du comptage de photons: le bruit d'injection de charge. À l'aide de ce contrôleur, une caméra EMCCD scientifique a été construite, caractérisée en laboratoire et testée à l'observatoire du mont Mégantic. Cette nouvelle caméra permet, entre autres, de réaliser des observations de la cinématique des galaxies par spectroscopie de champ intégral par interférométrie de Fabry-Perot en lumière Ha beaucoup plus rapidement, ou de galaxies de plus faible luminosité, que les caméras à comptage de photon basées sur des tubes amplificateurs. Le temps d'intégration nécessaire à l'obtention d'un rapport signal sur bruit donné est environ 4 fois moindre qu'avec les anciennes caméras. Les applications d'un tel appareil d'imagerie sont nombreuses: photométrie rapide et faible flux, spectroscopie à haute résolution spectrale et temporelle, imagerie limitée par la diffraction à partir de télescopes terrestres (lucky imaging), etc. D'un point de vue technique, la caméra est dominée par le bruit de Poisson pour les flux lumineux supérieurs à 0. 002 photon/pixel/image. D'un autre côté, la raie d'hydrogène neutre (HI) à 21 cm a souvent été utilisée pour étudier la cinématique des galaxies. L'hydrogène neutre a l'avantage de se retrouver en quantité détectable au-delà du disque optique des galaxies. Cependant, la résolution spatiale de ces observations est moindre que leurs équivalents réalisés en lumière visible. Lors de la comparaison des données HI, avec des données à plus haute résolution, certaines différences étaient simplement attribuées à la faible résolution des observations HI. Le projet THINGS (The HI Nearby Galaxy Survey a observé plusieurs galaxies de l'échantillon SINGS (Spitzer Infrared Nearby Galaxies Survey). Les données cinématiques du projet THIGNS seront comparées aux données cinématiques obtenues en lumière Ha, afin de déterminer si la seule différence de résolution spatiale peut expliquer les différences observées. Les résultats montrent que des différences intrinsèques aux traceurs utilisées (hydrogène neutre ou ionisé), sont responsables de dissemblances importantes. La compréhension de ces particularités est importante: la distribution de la matière sombre, dérivée de la rotation des galaxies, est un test de certains modèles cosmologiquesA new EMCCD (Electron multiplying Charge Coupled Device) controller is presented. It allows the EMCCD to be used for photon counting by drastically taking down its dominating source of noise : the clock induced charges. A new EMCCD camera was built using this controller. It has been characterized in laboratory and tested at the observatoire du mont Mégantic. When compared to the previous generation of photon counting cameras based on intensifier tubes, this new camera renders the observation of the galaxies kinematics with an integral field spectrometer with a Fabry-Perot interferometer in Ha light much faster, and allows fainter galaxies to be observed. The integration time required to reach a given signal-to-noise ratio is about 4 times less than with the intensifier tubes. Many applications could benefit of such a camera: fast, faint flux photometry, high spectral and temporal resolution spectroscopy, earth-based diffraction limited imagery (lucky imaging), etc. Technically, the camera is dominated by the shot noise for flux higher than 0. 002 photon/pixel/image. The 21 cm emission line of the neutral hydrogen (HI) is often used to map the galaxies kinematics. The extent of the distribution of the neutral hydrogen in galaxies, which goes well beyond the optical disk, is one of the reasons this line is used so often. However, the spatial resolution of such observations is limited when compared to their optical equivalents. When comparing the HI data to higher resolution ones, some differences were simply attributed to the beam smearing of the HI caused by its lower resolution. The THINGS (The HI Nearby Galaxy Survey) project observed many galaxies of the SINGS (Spitzer Infrared Nearby Galaxies Survey) project. The kinematics of THINGS will be compared to the kinematic data of the galaxies obtained in Ha light. The comparison will try to determine whether the sole beam smearing is responsible of the differences observed. The results shows that intrinsic dissimilarities between the kinematical tracers used are responsible of some of the observed disagreements. The understanding of theses differences is of a high importance as the dark matter distribution, inferred from the rotation of the galaxies, is a test to some cosmological models
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Nguyen, Khanh Linh. "Mesures optiques de profils de turbulence pour les futurs systèmes d'optique adaptative et d'observation". Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4242/document.
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La connaissance de la turbulence atmosphérique en visée horizontale permet de mieux appréhender la physique des flux de chaleur à l’interface sol-atmosphère. Elle permet également, en visée verticale, d’améliorer les performances des futurs systèmes d’optique adaptative grand-champ pour l’observation astronomique. Le profil de Cn² caractérise localement la force de la turbulence. La méthode CO-SLIDAR, développée par l’ONERA, permet de réaliser des profils de Cn² le long de la ligne de visée du télescope à partir des pentes et de scintillations mesurées par un Analyseur de Shack-Hartmann sur source double. Cette méthode a été validée en visée verticale mais n’avait pas encore montré son efficacité en visée horizontale. Les deux expériences à Lannemezan et à Châtillon-Meudon ont vu la mise en place d'un nouveau profilomètre Shack-Hartmann Infrarouge : le SCINDAR. Elles ont été réalisées sur des surfaces respectivement hétérogène et homogène par morceaux, et elles participent à la validation de la méthode pour des applications agronomiques et écologiques. Mon étude consiste à améliorer le traitement du signal du profilomètre SCINDAR et à valider la méthode CO-SLIDAR pour des mesures de la turbulence atmosphérique proche du sol. Cette méthode a été adaptée en utilisant un formalisme de propagation en onde sphérique. L'étude a permis d'identifier et prendre en compte des sources d'erreur dans le traitement : à savoir la vibration de la machine à froid de l'analyseur de front d'onde cryogénique du SCINDAR et l'étendue des sources dans les fonctions de poids du modèle direct posé pour le traitement des données. Mon étude se consacre à l’amélioration du traitement des données du SCINDAR et à la validation expérimentale des profils de Cn² obtenus avec des mesures de Cn² acquises par des scintillomètres. J'ai construit tout d'abord une base de données de pentes et scintillations de qualité vérifiée. Pour l'inversion des données, j'ai choisi la régularisation L1L2 qui est adaptée pour des mesures de Cn² proches du sol. La méthode de réglage des hyperparamètres de cette régularisation est non-supervisée. Elle permet d’augmenter la fiabilité et la précision de l’estimation du profil de Cn² de façon pragmatique à l'aide des erreurs relatives sur les paramètres turbulents macroscopiques. Le profilomètre SCINDAR avec la méthode CO-SLIDAR ainsi améliorée produit finalement des profils de Cn² d'excellente qualité. Ces profils sont comparés avec succès aux mesures des scintillomètres. L’ensemble de ces travaux constitue l'adaptation de la méthode CO-SLIDAR pour des mesures de la turbulence proche du solThe knowledge of atmospheric turbulence in horizontal aim allows to better understand the physics of the heat fluxes at the ground-atmosphere interface. It also allows, in vertical aim, to improve the performance of future wide-field adaptive optics systems for astronomical observation. The profile of Cn²locally characterizes the force of turbulence. The CO-SLIDAR method, developed by ONERA, allows profiles of Cn² along the line of sight of the telescope, from the slopes and scintillations of a double source measured by Shack-Hartmann analyzer. This method was validated in vertical aim but had not yet shown its effectiveness in horizontal aim. The two experiments in Lannemezan and Châtillon-Meudon introduced a new Shack-Hartmann Infrared profilometer: the SCINDAR. They were carried out on heterogeneous and piecewise homogeneous surfaces respectively, and they participate in the validation of the method for agronomic and ecological applications. My study consists of improving SCINDAR profilometer signal processing and validating the CO-SLIDAR method for near-ground atmospheric turbulence measurements. This method has been adapted using a spherical wave propagation formalism. The study identified and took into account sources of error in processing: the cold machine vibration of the SCINDAR cryogenic wavefront analyzer and the extent of the sources in the weight functions of the direct model set for data processing. My study focuses on improvement of the SCINDAR data processing and experimental validation profiles Cn² obtained with Cn² measurements acquired by scintillometers. I first built a database of slopes and scintillations of verified quality. For the inversion of the data, I chose the L1L2 regularization which is suitable for near-ground Cn² measurements. The method of setting the hyperparameters of this regularization is unsupervised. It makes it possible to increase the reliability and the accuracy of the Cn² profile estimation in a pragmatic way using the relative errors of the macroscopic turbulent parameters. The SCINDAR profilometer with the improved CO-SLIDAR method finally produces Cn² profiles of excellent quality. These profiles are successfully compared to scintillometer measurements. All of this work constitues the adaptation of the CO-SLIDAR method for measurements of near-ground turbulence
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Pereira, Jefferson de Sousa. "Construção de instrumentos de observação astronômica para o ensino de óptica geométrica". reponame:Repositório Institucional da UnB, 2016. http://repositorio.unb.br/handle/10482/23288.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Física, Programa de Pós-Graduação em Física, 2016.Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2017-04-05T17:04:58Z No. of bitstreams: 1 2016_JeffersondeSousaPereira.pdf: 3009029 bytes, checksum: c1c93380eee952cecca229304e89ff1a (MD5)
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O ensino de Astronomia está cada vez mais extinto nos currículos escolares. Por essa razão, acreditamos que inserir tópicos de Astronomia nas aulas de Física de maneira interdisciplinar é uma estratégia viável para que os alunos tenham contato com o tema. É a partir desta proposta que foram elaboradas aulas de Óptica Geométrica, com o intuito de montar lunetas galileanas (telescópios refletores), as quais foram aplicadas numa escola pública da cidade do Paranoá no Distrito Federal, em duas turmas de 2º ano do Ensino Médio. Ainda sim, dividimos essas aulas em duas etapas: momento tradicional – conteúdo de princípios da natureza da luz e espelhos (planos e esféricos) e aulas tradicionais – e momento prático – com conteúdo de refração da luz e lentes esféricas e aulas direcionadas à montagem da luneta galileana e oficina de montagem do equipamento com observação astronômica. Foram feitas avaliações nos dois momentos, a fim de realizar uma análise do desempenho dos alunos em cada um dos momentos, comparando as duas estratégias de ensino.
The astronomy education is increasingly extinct curricula. For this reason we believe that enter astronomical topics in physics classes in an interdisciplinary way is more feasible for students to have contact with the subject. It is with this view that elaborate geometric optics classes aiming to assemble Galilean telescopes (reflecting telescopes), and apply those lessons in a public school Paranoá city in the Federal District, in two groups of 2nd year of high school. Still, we divided these classes into two stages: the traditional time - the traditional classes and content principles of the nature of light and mirrors (flat and spherical) - and practical time - with refractive contents from light and spherical lenses, with classes aimed at Mount Galilean telescope and finally the equipment assembly workshop with astronomical observation. Evaluations were made on both occasions, in order to conduct a performance assessment of students in each of the moments, comparing the two teaching strategies.
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Heizer, Alda Lucia. "Observar o ceu e medir a terra : instrumentos cientificos e a participação do Imperio do Brasil na Exposição de Paris de 1889". [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287043.
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Orientador : Maria Margaret LopesTese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociencias
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Resumo: A presente pesquisa tem por finalidade contribuir para a História das Grandes Exposições da segunda metade do século XIX, sublinhando a participação do Império do Brasil nesses grandes eventos, em particular na Exposição Universal de Paris de 1889. Consideramos possível, ao analisar os catálogos de instrumentos científicos, relatórios, memórias, revistas científicas, entre outras fontes, identificar pistas que nos revelam que o Império do Brasil pretendia desfazer a imagem de flor exótica nos trópicos. A partir da constatação de que os trabalhos acadêmicos realizados no Brasil sobre estes grandes eventos, dos anos de 1980 para cá, não se ocuparam da participação dos países da América Latina, este trabalho pretende se desenvolver na confluência de linhas de pesquisa que, embora plenamente articuláveis, permanecem, até hoje, em grande parte dissociadas na produção historiográfica nacional. Trata-se de pesquisas em História das Exposições Universais e a História dos Instrumentos Científicos
Abstract: This present research has the purpose to contribute for the history of the Great Expositions of the second half of the XIX century, underlining the participation of the Brazilian Empire on these events, in particular in the Paris Universal Exposition in 1889. We found it possible, when analyzing the scientific instrument¿s catalogues, reports, memories, scientific magazines, among other sources, to identify tracks that reveal to us that the Brazilian Empire intended to appear under the image of the ¿Exotic flower of the tropics¿. After discover that the academic works that were made in Brazil about these great events, from 1980 until today, disregard the participation of the Latin American countries, this work intend to be developed in the confluence of the lines of research , although they can be articulated, remains until today dissociated in the national history production. It¿s about research on the history of the Great Universal Expositions and the History of Scientific Instruments
Doutorado
Doutor em Ensino e História de Ciências da Terra
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Oliveira, David Alisson Uchôa de. "As Grandes Navegações: aspectos matemáticos de alguns instrumentos náuticos". Universidade Federal da Paraíba, 2017. http://tede.biblioteca.ufpb.br:8080/handle/tede/9838.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The Age of Discovery was an important historical period that occurred between the end of the fteenth century and the beginning of the seventeenth century. It was marked in an European point of view by discovery and invasion of America, the transition from the Atlantic to the Indian Ocean in southern Africa and the rst circumnavigation travel. These transoceanic voyages were only possible thanks to a tremendous e ort to search for the development of sciences, especially, Mathematics. In the present work, we present the main instruments that was commonly used in that astronomical navigation, and a Mathematics involved on them period for.
A Era das Grandes Navegações foi um importante período histórico que ocorreu entre o m do século XV e o início do XVII e é marcada, para os europeus, pelo descobrimento das Américas, pelo estabelecimento da rota do Atlântico para o Índico pelo sul da África e pelas primeiras viagens de circunavegação do globo terrestre. Essas viagens transoceânicas só se tornaram possíveis graças a um esforço tremendo de busca pelo desenvolvimento das ciências, especialmente, a matemática, No presente trabalho, apresentamos os principais instrumentos que possibilitaram o desenvolvimento da navegação astronômica e a Matemática aliada à criação, constru ção e manuseio desses instrumentos náuticos antigos.
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Andrade, Denis Furtado de. "Otimização das câmeras astronômicas do instrumento Brazilian Tunable Filter Imager". Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3142/tde-26082016-160404/.
Resumo:
Este trabalho apresenta os resultados obtidos no processo de otimização realizado nas câmeras astronômicas do instrumento BTFI (Brazilan Tunable Filter Imager) instalado no telescópio SOAR, no Chile, para reduzir o ruído nos sinais. O instrumento BTFI opera com duas câmeras astronômicas de alto desempenho que utilizam detectores de imagens denominados EMCCDs. Esses detectores são sensores de imagem baseados em dispositivos de carga acoplada (CCDs) otimizados por um estágio integrado de multiplicação de elétrons por avalanche. Essa característica permite atingir ao mesmo tempo altas taxas de leitura (10 MHz) e níveis de ruído muito baixos (<1 elétron/pixel). Detectores CCD exigem temperaturas de operação da ordem de -100oC para operar com baixo ruído, o que demanda uma série de especificações técnicas quanto ao projeto da câmera. O trabalho aqui exposto fundamentou-se na otimização de aspectos mecânicos e eletrônicos de câmeras astronômicas com o intuito de se obter a melhor relação sinal-ruído, mostrando a importância do correto desenho mecânico (do ponto de vista térmico) e sua influência no comportamento eletrônico da câmera. São expostos os resultados obtidos com as duas câmeras em laboratório, os métodos e processos de caracterização utilizados, bem como as simulações térmicas e experimentos realizados em laboratório. Com as técnicas empregadas alcançou-se níveis de ruído total menores que 0,18 elétrons/pixel/segundo para exposições de 10 segundos. Os resultados atingidos foram observados nas duas câmeras do instrumento BTFI e foram validados em laboratório, onde demonstraram estabilidade durante 71 dias consecutivos. Por fim, é mostrada uma caracterização comparativa entre as duas câmeras quanto aos níveis de ruídos, ganho, estabilidade, eficiência quântica, linearidade e relação sinal-ruído.This work presents results of the optimization performed in the astronomical cameras from the Brazilian Tunable Filter Imager (BTFI), instrument for the SOAR Telescope in Chile, in order to reduce the signals noise. The BTFI instrument has two highperformance cameras equipped with detectors named EMCCDs, which are image sensors based on charge-coupled devices (CCDs) optimized by an electron multiplication integrated stage. This feature enables to achieve high readout rates (10 MHz) and very low noise levels (<1 electron/pixel) at the same time. CCD detectors demand running temperatures of about -100,sup>oC for very low noise operation, which requires a series of technical specifications for the camera design. The work shown here is based in the optimization of the mechanical and electronic aspects for the astronomical cameras, in order to obtain the best signal to noise ratio, showing the importance of the correct mechanical design (from the thermal point of view) and its influence on the camera electronic behavior. The laboratory results obtained with the two cameras, the characterization procedures, as well as the thermal simulations and laboratory ratification experiments that allowed achieve the results presented are exposed. Using such techniques it was possible to achieve total noise levels lower than 0.18 electron/pixel/second for 10 seconds of exposure time. The results achieved were observed in both BTFI cameras and were validated in laboratory showing 71 consecutive days of stability. Finally it is shown a comparative characterization between both cameras in: noise and gain levels, stability, quantum efficiency, linearity and signal to noise ratio.
43
Carvalho, Rui Pedro. "Ilustrações de instrumentos científicos de física e astronomia. Ilustrações de instrumentos científicos do Observatório Astronómico do Paço das Escolas e do Gabinete de Física do Museu da Ciência da Universidade de Coimbra". Master's thesis, Universidade de Évora, 2011. http://hdl.handle.net/10174/14706.
Resumo:
Este relatório destina-se a dar a conhecer os projectos que foram desenvolvidos no
âmbito de um estágio de final da I edição do Mestrado em Ilustração – vertente
Ilustração Científica. Este estágio decorreu no Museu da Ciência da Universidade de
Coimbra e teve como propósito conceber ilustrações dos instrumentos das colecções de
Física e do Observatório Astronómico que existiu no Paço das Escolas da UC. As
ilustrações destinam-se a ilustrar a função de alguns dos objectos expostos no Museu
cujas colecções, assim como, o Observatório Astronómico tiveram origem na grande
reforma que em 1772 o Marquês de Pombal operou na Universidade. No decorrer deste
relatório encontram-se descritos os processos de pesquisa, concepção e execução das
ilustrações para as colecções de Física e expôe-se também o processo de reconstituição
dos edifícios dos dois Observatórios Astronómicos que então foram projectados. Para os
dois projectos previa-se que os instrumentos fossem contextualizados nas várias épocas
históricas a que pertencem, pelo que tiveram uma terceira tarefa destinada a auxiliá-los:
o esboçar de trajes para os intervenientes nas ilustrações como resultado da pesquisa
pelos procedimentos das épocas envolvidas.
No final encontra-se um balanço geral da actividade com um resumo das tarefas
envolvidas, com as suas dificuldades, aprendizagens e considerações onde se expõe o
que foi possível levar a cabo e o que não o foi, rematando com um parecer sobre o
estágio e sobre a ilustração de História; ABSTRACT: The aim of this report is to provide knowledge about the projects developed as part of a
final traineeship of the First Edition of the Master in Illustration - scientific illustration
branch. This traineeship was developed at Science Museum of University of Coimbra,
in order to conceive illustrations about the instruments belonging to the collections of
Physics and Astronomic Observatory once existed in the courtyard of University. The
illustrations are intended to clarify the function of some of the objects on exhibition at
the Museum, which collections, as well as, the Astronomical Observatory where build
as result of a profound changes which Marquis of Pombal did at the University. During
this report are described the processes of research, conceiving and making of the
illustrations for collections of Physics. It also explains the reconstruction of two
Astronomical Observatories so projected. The two projects were thought to insert
instruments on their respective times. That’s why they had a third task to support them:
the drafting of costumes for people contained in the illustrations.
This report ends with a general assessment of the activity with a summary of the tasks
involved and their difficulties, know ledges achieved and exposes the considerations
which it was possible to carry out and what was not, finishing with an opinion about
the traineeship and historical illustration.
44
Veras, Alcione da Anunciacao Caetano Lobao. "O uso de modelos e aparelhos no ensino de astronomia nas séries iniciais do ensino básico: instrumentos de mediação para o aprendizado". Universidade Federal de Minas Gerais, 2007. http://hdl.handle.net/1843/FAEC-855HUC.
Resumo:
The thematic that this research intended to investigate inserts in the context of the work developed with children from a classroom of the initial series in activity of Natural Sciences Education from the Project Astronomy. This research has for episthemologic premise the perspective that the social interaction in specific institutional spaces is the responsible axis for the knowledge construction process. The individual becomes subject of the learning in the interaction process with the culture and interlocution with the other, which according to Vygotsky, (1986), it integrates the social and the activity. The social one, in this perspective, constitutes the source of the child's conceptual development and it characterizes the organization of the common activity and the students' learning. With Project Astronomy's development it was aimed to contribute for the analysis and reflection on the use of mediation resources as models and devices in the construction of the physical knowledge in the school. The orientation for the pedagogic work in this research context an the school atmosphere tried to provide the effective use of such resources on the part of the children, in constructed situations so that their presence became necessary for the nature of the established interactions between children and the object of the knowledge. The necessity of use and construction of the mediations was a fundamental resource for the rescue of the phenomena, by means of Questioning strategies, investigation and reflection. The research project consisted of producing, with the teacher and researchers participation, interventions that allowed to identify and to evaluate the fulfilled functions and the impacts for fortune produced by the use of the mediation resources in the development and the children's learning. The interventions in the school had occurred during the school year of 2005A temática que esta pesquisa se propôs investigar se insere no contexto do trabalho desenvolvido com crianças de uma sala de aula das séries iniciais em atividades de ensino de ciências naturais a partir do Projeto Astronomia. Esta pesquisa tem por premissa epistemológica a perspectiva de que a interação social em espaços institucionais específicos é o eixo norteador do processo de construção de conhecimentos. O indivíduo se torna sujeito da aprendizagem no processo de interação com a cultura e de interlocução com o outro, o que segundo Vygotsky, (1986), integra o social e a atividade. O social, nessa perspectiva, constitui a fonte de desenvolvimento conceitual da criança e caracteriza a organização da atividade comum e do aprendizado dos estudantes. Com o desenvolvimento do Projeto Astronomia visou-se contribuir para a análise e reflexão sobre o uso de recursos mediacionais como modelos e aparelhos na construção do conhecimento físico na escola. A orientação para o trabalho pedagógico no contexto desta pesquisa no ambiente escolar procurou proporcionar o uso efetivo de tais recursos por parte das crianças, em situações construídas para que sua presença se fizesse necessária pela natureza das interações estabelecidas entre crianças e objeto do conhecimento. A necessidade de utilização e construção das mediações foi um recurso fundamental para o resgate dos fenômenos, por meio de estratégias de problematização, investigação e reflexão. O projeto de pesquisa consistiu em produzir, com a participação da professora e da pesquisadora, intervenções que permitissem identificar e avaliar as funções cumpridas e os impactos por ventura produzidos pelo uso dos recursos mediacionais no desenvolvimento e aprendizagem das crianças. As intervenções na escola ocorreram durante o ano letivo de 2005.
45
Cavalcanti, Luiz Eduardo Mendonça. "Sistema de controle para o filtro óptico sintonizável Fabry-Perot do instrumento BTFI". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3142/tde-06042011-115126/.
Resumo:
Este trabalho trata do desenvolvimento de um sistema de controle para um módulo do instrumento astronômico BTFI (Brazilian Tunable Filter Imager), um filtro óptico sintonizável altamente versátil que está instalado no telescópio SOAR, localizado no Chile. Será empregado neste instrumento um novo interferômetro Fabry-Perot, capaz de realizar observações em uma ampla faixa de resoluções espectrais. Para operar com resolução espectral variável, o Fabry-Perot proposto neste projeto terá uma faixa mais ampla de ajuste do vão entre suas placas refletivas, utilizando atuadores piezelétricos amplificados com grande capacidade de deslocamento e sensores capacitivos de alta precisão. O novo controlador apresenta uma malha de controle totalmente digital, implementada com um DSP (Digital Signal Processor) sintetizado num dispositivo FPGA (Field-programmable Gate Array). Na primeira etapa do desenvolvimento, trabalhou-se com um sistema de posicionamento nanométrico utilizando um protótipo simplificado com um canal composto por um sensor capacitivo de distância e um atuador piezelétrico. A partir dos bons resultados obtidos no sistema de um canal, realizou-se a expansão para um sistema de controle multi-malha de três canais com protótipo do Fabry-Perot, mas sem o uso das placas de vidro refletivas definitivas. O sistema permite controlar o posicionamento para cada canal individualmente ou os três em simultâneo, com desempenho adequado para os requisitos do filtro óptico sintonizável Fabry-Perot.This work aims the development of a control system for a module of the BTFI astronomical instrument (Brazilian Tunable Filter Imager), a highly versatile optical tunable filter, deployed on the SOAR Telescope. The instrument will employ a new Fabry-Perot interferometer, which is able to provide observations in a wide range of spectral resolutions. In order to achieve variable spectral resolution, the new Fabry- Perot proposed in this project will present a larger range for adjusting the air gap between its reflective plates, using amplified piezoelectric actuators presenting high stroke capability and high precision capacitive sensors. The new controller presents a full digital control loop, implemented in a DSP (Digital Signal Processor) synthesized through a FPGA device (Field-programmable Gate Array). During the first phase of the development, it was used a nanometric positioning system using a single channel prototype comprising one capacitive sensor and one piezoelectric actuator. The good results obtained using the single channel prototype led to the expansion to a 3- channel multi-loop control system on a Fabry-Perot prototype which comprises dummy plates. The system allows controlling the position of each channel separately or simultaneously, presenting performance in accordance with the requirements of a Fabry-Perot optical tunable filter.
46
Quint, Bruno Corrêa. "Modelagem numérica de alto nível de filtros do tipo Fabry-Pérot e de redes de difração holográficas para o instrumento BTFI". Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-18102010-195658/.
Resumo:
O trabalho apresentado nesta dissertação foi motivado essencialmente pelo projeto de construção de um novo instrumento a ser instalado no telescópio SOAR, no Chile. Este instrumento, chamado de \\textit{Brazilian Tunable Filter Imager} - BTFI, conta com várias novidades dentro da área de instrumentação astronômica. Uma delas envolve a utilização de duas redes de difração em série de modo a atuarem como um filtro espectral com uma resolução mais baixa. Aqui é mostrado o estudo realizado envolvendo dois diferentes modelos encontrados na literatura para simular numericamente a eficiência destas redes. Com estas simulações foi possível escolher um conjunto de redes a serem utilizadas no instrumento visando cobrir todo o espectro óptico com diferentes resoluções espectrais. Outra ferramenta estudada foi o filtro espectral do tipo Fabry-Pérot. Partindo de uma revisão teórica de interferência de raios múltiplos, apresenta-se também algumas características encontradas nos cubos de dados obtidos ao fazer uso de filtros deste tipo. Por fim, é descrito o software que foi criado buscando fornecer cubos de dados sintéticos para o desenvolvimento de novos pacotes numéricos para trabalhar com dados obtidos com um interferômetro Fabry-Pérot, além de auxiliar na compreensão de obtenção destes cubos.The work presented in this dissertation was motivated primarily by the construction project of a new instrument to be installed on the SOAR telescope in Chile. This instrument, called \\textit {Brazilian Tunable Filter Imager} - BTFI, features several innovations within the area of astronomical instrumentation. One of them involves the use of two diffraction gratings in series in order to act as a spectral filter with a lower resolution. It is shown here the study involving two different models found in the literature to simulate the efficiency of these gratings. With these simulations it was possible to choose a set of gratings to be used in the instrument in order to cover the entire optical spectrum with different spectral resolutions. Another tool studied was the filter spectral type Fabry-Pérot. Starting from a theoretical review of interference of multiple beams, it is presented some features found in the data cubes obtained by making use of filters of this type. Finally, we describe the software that was created to provide synthetic data cubes for developing new packages for working with numerical data obtained with a Fabry-Perot interferometer, in addition to helping to raise understanding of these cubes.
47
Bortoli, Fabio da Silva. "Sistemas vibracionais do detector de ondas gravitacionais Mário Schenberg". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-02052012-102802/.
Resumo:
O detector de ondas gravitacionais Mário Schenberg consiste de uma massa ressonante esférica de Cu(94%)Al(6%) com 65cm de diâmetro, pesando aproximadamente 1,15T, com um Q mecânico da ordem de 106 e todos os sistemas que possibilitam o seu funcionamento como detector de ondas gravitacionais. O projeto do detector prevê para este uma sensibilidade da ordem de 10-20 (em deformação). Para isso dependerá da eficiência dos sistemas vibracionais que utiliza. Neste trabalho os casadores mecânicos de impedância, foram simulados com um programa de elementos finitos e otimizados quanto à sua banda e acoplamento vibracional. Foi feita a análise do sistema de isolamento vibracional da nova suspensão, por meio da resposta em frequência do ruído sísmico na superfície da esfera, nos mesmos locais onde estão conectados os transdutores. Foi proposto um projeto novo para atenuar os ruídos provenientes do cabeamento que conduz os sinais de micro-ondas. Foi avaliado o efeito do ruído sísmico introduzido na suspensão e na esfera, também nos locais dos transdutores, utilizando este novo projeto. É apresentado um projeto para a conexão térmica do refrigerador por diluição, que a análise por simulação numérica demonstrou ser eficaz. A modelagem para análise vibracional é a melhor já feita para detectores esféricos, isto se comparada às que foram encontrados na literatura. Os resultados alcançados demonstraram que as atenuação em todos os sistemas analisados são adequadas às metas do projeto do detector Mário Schenberg, ou seja, os ruídos remanescentes estão abaixo do ruído térmico esperado na temperatura de 50mK.The Gravitational Wave detector Mario Schenberg consist of a spherical resonant-mass made of CuAl(6%) with 65 cm diameter e weighting 1.15 Ton, with a Mechanical quality factor of about 106 and all the systems that allows it to word as a gravitational wave detector. The detector design was made for it to reach a sensitivity of 10-20 (strain sensitivity). To reach this goal it depends on the efficiency of the it vibrational systems. In this work the transducers mechanical impedance matchers were simulated with a finite element program and optimized in its band and vibrational coupling. A analysis of the vibrational isolation of the new suspension was made by the frequency response of the seismic noise on the sphere surface, on the same places where they will be connected to the transducers. A new design for attenuation of the noise due to microwave cabling was proposed. The seismic noise introduced on the suspension and on the sphere was simulated using this new design. A design for the dilution refrigerator thermal connection is presented, and its performance is measured in a analysis in a finite element moddeling, and showed itself efficienty. This vibration model for the detector is the best one ever made for spherical detectors, if compared to the literature. Results obtained showed that the atennuation in all the analysed systems are compatible to the Mário Schenberg detector design goals, it means that, the remaining noises are below the expected thermal noise at the temperature of 50 mK.
48
Marchiori, Victor. "Extraction photométrique bord des étoiles de la mission PLATO : masques photométriques optimaux pour la détection de planètes extra-solaires In-flight photometry extraction of PLATO targets Optimal apertures for detecting extrasolar planets The PLATO Solar-like Light-curve Simulator A tool to generate realistic stellar light-curves with instrumental effects representative of the PLATO mission". Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEO014.
Resumo:
PLAnetary Transits and Oscillations of stars (PLATO) est une mission scientifique spatiale européenne dédiée à la sismologie stellaire et à la recherche d’exoplanètes, et dont le développement est coordonné par l’Agence Spatiale Européenne. Avec un intérêt majeur sur des planètes du type terrestre située dans la zone habitable des étoiles du type solaire de la séquence principale, cette mission repose sur de la photométrie de très haute précision et exige une très grande stabilité des mesures. Elle s’appuie sur des techniques bien éprouvées : la méthode de transits pour la détection des planètes, suivie de mesures de vitesses radiales réalisées au sol, et l'analyse des oscillations stellaires pour la caractérisation des leurs étoiles hôtes. Grace à son très large champ de vue couvrant plus de deux mille dégrées carrés du ciel, l’instrument PLATO sera capable d’observer plusieurs centaines de milliers d’étoiles de magnitude apparente inférieure à treize dans le visible, et de détecter des milliers de systèmes planétaires. Par ailleurs, en raison des contraintes télémétriques du satellite, l’extraction photométrique de la majorité des étoiles devra être effectuée à bord en s’appuyant sur des méthodes optimisées. Pour autant, la méthode d’extraction photométriques par masques a été adoptée pour sa faisabilité compte-tenu des contraintes à bord. Dans ce contexte, la problématique de développement des masques photométriques optimaux représente le cœur du travail de recherche présenté dans cette thèse. Dans les missions précédentes de la même catégorie de PLATO, à savoir CoRoT, Kepler et TESS, des masques photométriques ont été conçus selon une approche reposant uniquement sur la minimisation du rapport bruit sur signal, car la sensibilité à laquelle un transit planétaire peut être identifié, dans une courbe de lumière, est fortement corrélée à son niveau de bruit. En revanche, plus il est facile d'identifier une planète, en raison d'un niveau de bruit suffisamment faible, plus élevée est la probabilité que des objets en arrière-plan entrant dans la scène (par exemple des systèmes binaires reproduisant des vrais transits planétaires) soient détectés. Étant donné que la plupart des étoiles-cible de PLATO n’auront pas des images au sol pour l’identification des faux positifs, une conception de masques photométriques reposant uniquement sur la sensibilité de détection des vrais transits planétaires, sans faire suffisamment attention aux potentiels faux positifs, n’est donc pas forcément la meilleure stratégie. Pour vérifier cette hypothèse, deux métriques scientifiques ont été introduites nous permettant de quantifier directement la sensibilité d'un masque à la détection des vrais, d’une part, et de faux transits planétaires, d’autre part. Ainsi, le masque optimal a été défini comme étant celui qui donne le meilleur compromis entre ces deux métriques. Cette approche, originale à cette thèse, s’est avérée décisive pour la détermination d’un modèle de masque statistiquement capable de détecter des planètes de façon quasi-optimale, tout en étant substantiellement moins sensible aux faux positifs. Globalement, ces travaux constituent une étape importante dans la conception des chaînes de traitement des données bord et sol de la mission PLATO, ainsi que pour ses algorithmes de détection et de caractérisation des transits planétairesPLAnetary Transits and Oscillations of stars (PLATO) is a European spatial scientific mission dedicated to asteroseismology and searching for exoplanets, and whose development is being carried out by the European Space Agency. With focus on Earth-like planets orbiting the habitable zone of main-sequence Sun-like stars, the mission relies on very high precision photometry and requires great stability of measurements. The mission is founded upon well-proven techniques: the transit method for detecting exoplanets, along with radial velocity follow-up from the ground, and the analysis of stellar oscillations for characterizing their host stars. Thanks to its very large field of view encompassing more than two thousand square degrees of the sky, the PLATO instrument will be able to observe several hundreds of thousands of stars with apparent magnitude lower than thirteen in the visible band, and thousands of planetary systems. In contrast, because of satellite telemetry constraints, photometry will have to be extracted in flight for most of the PLATO targets. For that, mask-based (aperture) photometry was adopted because of its sufficiently high performance and relatively low complexity for implementing on board. In this context, the development of optimal photometric apertures represents the core of the research work presented in this thesis. In the previous missions of the same category of PLATO (i.e. CoRoT, Kepler and TESS), photometric apertures were designed following an approach based uniquely on the minimization of the noise-to-signal ratio, because the sensitivity at which a planet transit can be found in a light curve is strongly correlated to its noise level. On the other hand, the higher the ease in identifying a transit-like signal because of a sufficiently low noise level, the higher the probability that background objects in the scene (e.g. binary systems reproducing legitimate planet transits) are detected. Since most of the PLATO targets will not have images available on ground for the identification of false positives, conceiving photometric masks based solely on how well a transit-like signal can be detected, paying no attention to potential false positives may not be the best strategy. To verify the consistence of this hypothesis, two science metrics were introduced allowing one to directly quantify the sensitivity of an aperture in detecting true and false planet transits. Then, the optimal aperture was defined as that which gives the best compromise between these two metrics. Such an approach, novel to this thesis, has been proven to be decisive for the determination of a mask model capable to provide near maximum planet yield and substantially reduced occurrence of false positives. Overall, this work constitutes an important step in the design of both on-board and on-ground science data processing pipelines of the PLATO mission
49
"Instrument Design and Radiation Pattern Testing for Terahertz Astronomical Instruments". Doctoral diss., 2018. http://hdl.handle.net/2286/R.I.49235.
Resumo:
abstract: The Milky Way galaxy is a powerful dynamic system that is highly efficient at recycling material. Stars are born out of intergalactic gas and dust, fuse light elements into heavier elements in their cores, then upon stellar death spread material throughout the galaxy, either by diffusion of planetary nebula or by explosive events for high mass stars, and that gas must cool and condense to form stellar nurseries. Though the stellar lifecycle has been studied in detail, relatively little is known about the processes by which hot, diffuse gas ejected by dying stars cools and conglomerates in the interstellar medium (ISM). Much of this mystery arises because only recently have instruments with sufficient spatial and spectral resolution, sensitivity, and bandwidth become available in the terahertz (THz) frequency spectrum where these clouds peak in either thermal or line emission. In this dissertation, I will demonstrate technology advancement of instruments in this frequency regime with new characterization techniques, machining strategies, and scientific models of the spectral behavior of gas species targeted by these instruments.
I begin this work with a description of radiation pattern measurements and their use in astronomical instrument characterization. I will introduce a novel technique to measure complex (phase-sensitive) field patterns using direct detectors. I successfully demonstrate the technique with a single pixel microwave inductance detectors (MKID) experiment. I expand that work by measuring the APEX MKID (A-MKID) focal plane array of 880 pixel detectors centered at 350 GHz. In both chapters I discuss the development of an analysis pipeline to take advantage of all information provided by complex field mapping. I then discuss the design, simulation, fabrication processes, and characterization of a circular-to-rectangular waveguide transformer module integrated into a circularly symmetric feedhorn block. I conclude with a summary of this work and how to advance these technologies for future ISM studies.Dissertation/Thesis
Doctoral Dissertation Exploration Systems Design 2018
50
Wehbe, Bachar. "Atmospheric Dispersion Correction for High Resolution Astronomical Instruments". Doctoral thesis, 2021. https://hdl.handle.net/10216/134155.