1. The Cherenkov transparency coefficient for the atmospheric monitoring and array calibration at the Cherenkov Telescope Array SouthStanislav Stefanik, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Opis: Reconstruction of energies of very-high-energy γ–rays observed by imaging atmospheric Cherenkov telescopes is affected by changes in the atmospheric conditions and the performance of telescope components. Reliable calibration schemes aimed at these effects are necessary for the forthcoming Cherenkov Telescope Array (CTA) to achieve its goals on the maximally allowed systematic uncertainty of the global energy scale. A possible means of estimating the atmospheric attenuation of Cherenkov light is the method of the Cherenkov transparency coefficient (CTC). The CTC is calculated using the telescope detection rates, dominated by the steady cosmic ray background, while properly correcting for the hardware and observational conditions.
The coefficient can also be used to relatively calibrate the optical throughput of telescopes on the assumption of homogeneous atmospheric transparency above the array. Using Monte Carlo simulations, we investigate here the potential of the CTC method for the atmospheric monitoring and telescope cross-calibration at the CTA array in the southern hemisphere. We focus on the feasibility of the method for the array of telescopes of three sizes in different observation configurations and under various levels of atmospheric attenuation.
Ključne besede: very-high-energy gamma-ray astronomy, Cherenkov Telescope Array (CTA) Observatory, imaging atmospheric Cherenkov telescopes (IACTs), atmospheric monitoring, IACT calibration
Objavljeno v RUNG: 14.11.2024; Ogledov: 437; Prenosov: 4
 Celotno besedilo (1,90 MB)
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2. Satellite Data for Atmospheric Monitoring at the Pierre Auger ObservatoryA. Puyleart, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2022, objavljeni znanstveni prispevek na konferenci Opis: Atmospheric monitoring over the 3000 km^2 of the Pierre Auger Observatory can be supplemented by satellite data. Methods for night-time cloud detection and aerosol cross-checking were created using the GOES-16 and Aeolus satellites, respectively. The geostationary GOES-16 satellite provides a 100% up-time view of the cloud cover over the observatory. GOES-13 was used until the end of 2017 for cloud monitoring, but with its retirement a method based on GOES-16 data was developed. The GOES-16 cloud detection method matches the observatory’s vertical laser cloud detection method at a rate of ∼90%. The Aeolus satellite crosses the Pierre Auger Observatory several times throughout the year firing UV-laser shots. The laser beams leave a track of scattered light in the atmosphere that can be observed by the light sensors of the observatory fluorescence telescopes. Using a parametric model of the aerosol concentration, the laser shots can be reconstructed with different combinations of the aerosol parameters. A minimization procedure then yields the parameter set that best describes the aerosol attenuation. Furthermore, the possibility of studying horizontal homogeneity of aerosols across the array is being investigated.
Ključne besede: Pierre Auger Observatory, indirect detection, fluorescence detection, ultra-high energy, cosmic rays, atmospheric monitoring, satellite monitoring, cloud detection, aerosols, UV laser shots
Objavljeno v RUNG: 04.10.2023; Ogledov: 1950; Prenosov: 7
Celotno besedilo (2,92 MB)
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3. Observation of the Cumbre Vieja volcano plume above the Observatorio del Roque de los Muchachos with the Barcelona Raman LIDARMiha Živec, Otger Ballester, Oscar Blanch, Juan Boix, Paolo G. Calisse, Anna Campoy Ordaz, Michele Doro, Lluis Font, Rafael Garcia, Markus Gaug, Roger Grau, Manel Martinez, David Roman, Samo Stanič, Santiago Ubach Ramírez, Marko Zavrtanik, 2022, objavljeni znanstveni prispevek na konferenci Ključne besede: lidar, remote sensing, CTA, CTAO, Cumbre Vieja, atmospheric monitoring, volcano
Objavljeno v RUNG: 13.02.2023; Ogledov: 2012; Prenosov: 22
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4. Real-time Measurements with Atmospheric Instruments at the Pierre Auger ObservatoryViolet M. Harvey, Andrej Filipčič, Gašper Kukec Mezek, Marta Trini, Samo Stanič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Ključne besede: ultra-high energy cosmic rays, Pierre Auger Observatory, atmospheric monitoring, instrumentation
Objavljeno v RUNG: 24.07.2020; Ogledov: 3468; Prenosov: 118
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5. Polarization Raman Lidar for Atmospheric Monitoring in the Vipava ValleyLonglong Wang, Samo Stanič, William Eichinger, Xiaoquan Song, Marko Zavrtanik, 2020, objavljeni znanstveni prispevek na konferenci Opis: We report on the design, construction and performance of a polarization Raman lidar, built for atmospheric monitoring in the Vipava valley in SW Slovenia, a regional air pollution hot-spot where aerosols are expected to originate from a number of different sources. Its key features are automatized remote operation capability and indoor deployment, which provide high duty cycle in all weather conditions. System optimization and performance studies include the calibration of the depolarization ratio, merging of near-range (analog) and far-range (photon-counting) data, determination of overlap functions and validation of the retrieved observables with radiosonde data.
Ključne besede: polarization Ramal lidar, Vipava valley, atmospheric monitoring
Objavljeno v RUNG: 08.07.2020; Ogledov: 3974; Prenosov: 0
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6. Atmospheric monitoring and array calibration in CTA using the Cherenkov Transparency CoefficientStanislav Stefanik, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2017, objavljeni znanstveni prispevek na konferenci Ključne besede: Cherenkov Transparency Coefficient, CTA, Atmospheric monitoring
Objavljeno v RUNG: 16.02.2018; Ogledov: 3890; Prenosov: 163
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7. The ARCADE Raman Lidar System for the Cherenkov Telescope ArrayLaura Valore, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Ključne besede: Cherenkov Telescope Array, atmospheric monitoring, ARCADE Raman Lidar
Objavljeno v RUNG: 16.02.2017; Ogledov: 4607; Prenosov: 187
Celotno besedilo (1,24 MB) |
8. Real-time atmospheric monitoring for the Cherenkov Telescope Array using a wide-field optical telescopeJan Ebr, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Ključne besede: Cherenkov Telescope Array, atmospheric monitoring, wide-field optical telescope
Objavljeno v RUNG: 15.02.2017; Ogledov: 4931; Prenosov: 187
Celotno besedilo (5,49 MB) |
9. Studies in the atmospheric monitoring at the Pierre Auger Observatory using the upgraded Central Laser FacilityCarlos Medina-Hernandez, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The Fluorescence Detector (FD) at the Pierre Auger Observatory
measures the intensity of the scattered light from laser tracks
generated by the Central Laser Facility (CLF) and the eXtreme
Laser Facility (XLF) to monitor and estimate the vertical
aerosol optical depth (τ(z,t)). This measurement is needed to
obtain unbiased and reliable FD measurements of the arrival
direction and energy of the primary cosmic ray, and the depth
of the maximum shower development. The CLF was upgraded
substantially in 2013 with the addition of a solid state laser,
new generation GPS, a robotic beam calibration system, better
thermal and dust isolation, and improved software. The upgrade
also included a back-scatter Raman LIDAR to measure τ(z,t).
The new features and applications of the upgraded instrument
are described. These include the laser energy calibration
and the atmospheric monitoring measurements. The first τ(z,t)
results and comparisons after the upgrade are presented using different methods. The first method compares the FD hourly
response to the scattered light from the CLF (or XLF) against
a reference hourly profile measured during a clear night where
zero aerosol contents are assumed. The second method simulates
FD responses with different atmospheric parameters and selects the parameters that provide the best fit to the actual FD
response. A third method uses the new Raman LIDAR receiver
in-situ to measure the back-scatter light from the CLF laser.
The results show a good data agreement for the first and second
methods using FD stations located at the same distance from the
facilities. Preliminary results of τ(z,t) using the Raman LIDAR
are presented as well.
Ključne besede: Pierre Auger Observatory, extensive air showers, the Fluorescence Detector, atmospheric monitoring, vertical aerosol optical depth, the Central Laser Facility, the eXtreme Laser Facility
Objavljeno v RUNG: 03.03.2016; Ogledov: 6096; Prenosov: 184
Celotno besedilo (3,96 MB) |
10. Lightning Detection at the Pierre Auger ObservatoryJulian Rautenberg, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The Auger Engineering Radio Array, an extension of the Pierre
Auger Observatory with antennas in the MHz range, requires to
monitor the atmospheric conditions, which have a large influence
on the radio emission of air showers. In particular, amplified
signals up to an order of magnitude have been detected as an
affect of thunderstorms. For a more detailed investigation and
more generally, for detecting thunderstorms, a new lightning
detection system has been installed at the Pierre Auger
Observatory in Argentina. In addition, an electric-field mill
measures the field strength on ground level at the antenna
array. With these measurements, data periods affected
by thunderstorms can be identified. Additionally, a lightning
trigger for the water-Cherenkov detectors was developed to read
out individual stations when a lightning was detected nearby.
With these data, a possible correlation between the formation
of lightning and cosmic rays can be investigated even at low
energies of about 10[sup]15 eV. The structure and functionality
of the lightning detection are described and first data
analyses are shown.
Ključne besede: Pierre Auger Observatory, Auger Engineering Radio Array, atmospheric monitoring, lightning detectors
Objavljeno v RUNG: 03.03.2016; Ogledov: 5540; Prenosov: 200
Celotno besedilo (1,10 MB) |
