24 research outputs found

    FRAM telescopes and their measurements of aerosol content at the Pierre Auger Observatory and at future sites of the Cherenkov Telescope Array

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    A FRAM (F/(Ph)otometric Robotic Atmospheric Monitor) telescope is a system of a robotic mount, a large-format CCD camera and a fast telephoto lens that can be used for atmospheric monitoring at any site when information about the atmospheric transparency is required with high spatial or temporal resolution and where continuous use of laser-based methods for this purpose would interfere with other observations. The original FRAM has been operated at the Pierre Auger Observatory in Argentina for more than a decade, while three more FRAMs are foreseen to be used by the Cherenkov Telescope Array (CTA). The CTA FRAMs are being deployed ahead of time to characterize the properties of the sites prior to the operation of the CTA telescopes; one FRAM has been running on the planned future CTA site in Chile for a year while two others are expected to become operational before the end of 2018. We report on the hardware and current status of operation and/or deployment of all the FRAM instruments in question as well as on some of the preliminary results of integral aerosol measurements by the FRAMs in Argentina and ChileComment: Proceedings of AtmoHEAD 201

    New developments in aerosol measurements using stellar photometry

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    The idea of using stellar photometry for atmospheric monitoring for optical experiments in highenergy astrophysics is seemingly straightforward, but reaching high precision of the order of 0.01 in the determination of the vertical aerosol optical depth (VAOD) has proven difficult. Wide-field photometry over a large span of altitudes allows a fast determination of VAOD independently of the absolute calibration of the system, while providing this calibration as a useful by-product. Using several years of data taken by the FRAM (F/(Ph)otometric Robotic Atmospheric Monitor) telescope at the Pierre Auger Observatory in Argentina and about a year of data taken by a similar instrument deployed at the planned future Southern site of the Cherenkov Telescope Array in Chile, we have developed methods to improve the precision of this measurement technique towards and possibly beyond the 0.01 mark. Detailed laboratory measurements of the response of the whole system to both the spectrum and intensity of incoming light have proven indispensable in this analysis as the usual assumption of linearity of the CCD detectors is not valid anymore for the conditions of the observations

    Phase analysis using Fourier transform profilometry

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    The profilometry method used here is the Fourier-Transform Profilometry Method that was originally published by Takeda in 1982. The geometry of the experiment is very similar that used in Moiré Topography, but the advantage of this method is only one image of the projected grating is necessary to produce the resulting object´s fringes

    Měření drsnosti povrchu pomocí optických metod

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    The article treats of roughness measurement by means of optical methods. We own two unique optical devices enabling roughness measurement (CASI and SCAN). Both were produced by Schmitt Industries. Measuring range is from 1 Ă… to 2000 Ă…

    Materiology of mouldings for automobile industry

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    This article treats of optical methods, that investigate defect of mouldings designed for automobile industry. We use simple optical system and image processing algorithm to measure surface deformation. The sources of defect usually are: scratch, bulge, grey, bristle etc

    Analysis of abrasion of cotyles

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    The 3D optical scanning topography is one possible method of an analysis of the cotyle deformation. The object of this experiment is to quantify the decrease of cotyle material. The scanning object is polyethylene coxa cotyle ABG1.The cotyle is a plastic fossette surounded with metal cage, which is connected with a coxa of the patients. Due to use the deformation of the surface arise
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