Related papers: Absolute reflectance of a concave mirror used for …
Black materials play a critical role in applications such as image registration, camera calibration, stray light suppression, and visual design. Although many such materials appear similarly dark under diffuse illumination, their…
A calibrated laser pulse propagating through the atmosphere produces a flash of Rayleigh scattered light with an intensity that can be calculated very accurately when atmospheric conditions are good. This is used in a technique developed…
In gamma ray astronomy muon events have a distinct feature of casting ring-like images on the sensor plane, thus forming a well known signal class for Cherenkov telescopes. These ring-like images can then be used to deduce the optical point…
The monitoring of the atmosphere is very relevant for Imaging Atmospheric Cherenkov Telescopes. Adverse weather conditions (strong wind, high humidity, etc.) may damage the telescopes and must therefore be monitored continuously to…
Galactic diffuse emission has provided us with evidence for cosmic ray acceleration throughout the Galaxy and the background for searches for physics beyond the Standard Model. However, only the very limited measurements of the diffuse flux…
Radiation pressure on a flat mirror submerged in a transparent liquid, depends not only on the refractive index n of the liquid, but also on the phase angle psi_0 of the Fresnel reflection coefficient of the mirror, which could be anywhere…
The ground-based imaging atmospheric Cherenkov technique is currently the most powerful observation method for very high energy gamma rays. With its specially designed camera and readout system, the MAGIC Telescope is capable of observing…
Context. The response of imaging atmospheric Cherenkov telescopes to incident {\gamma}-ray-initiated showers in the atmosphere changes as the telescopes age due to exposure to light and weather. These aging processes affect the…
In this work, we present a method for absolute measurement of air fluorescence yield based on high resolution optical emission spectroscopy. The absolute measurement of the air fluorescence yield is feasible using the Cherenkov light,…
The energy-dependent abundance of elements in cosmic rays plays an important role in understanding their acceleration and propagation. Most current results are obtained either from direct measurements by balloon- or satellite-borne…
The angular size of a star is a critical factor in determining its basic properties. Direct measurement of stellar angular diameters is difficult: at interstellar distances stars are generally too small to resolve by any individual imaging…
Optical spectroscopy techniques such as differential reflectance and transmittance have proven to be very powerful techniques to study 2D materials. However, a thorough description of the experimental setups needed to carry out these…
The imaging sharpness of an X-ray telescope is chiefly determined by the optical quality of its focusing optics, which in turn mostly depends on the shape accuracy and the surface finishing of the grazing-incidence X-ray mirrors that…
We consider a slow particle with wave function $\psi_t(\vec{x})$, moving freely in some direction. A mirror is briefly switched on around a time $T$ and its position is scanned. It is shown that the measured reflection probability then…
Imaging atmospheric Cherenkov telescopes are continuously exposed to varying weather conditions that have short and long-term effects on their response to Cherenkov light from extensive air showers. This work presents the implementation of…
Usually the Imaging Atmospheric Cherenkov Telescopes, used for the ground-based gamma-ray astronomy in the very high energy range 50 GeV - 50 TeV, perform air shower observations till the zenith angle of ~60 deg. Beyond that limit the…
The MAGIC telescope is an imaging atmospheric Cherenkov telescope, designed to observe very high energy gamma-rays while achieving a low energy threshold. One of the key science goals is fast follow-up of the enigmatic and short lived…
In this work we study in details the influence of pure astronomical refraction on solar metrologic measurements made from ground-based full disk imagery and provide the tools for correcting the measurements and estimating the associated…
The Cherenkov Telescope Array (CTA) is the next generation very high-energy gamma-ray observatory, with at least 10 times higher sensitivity than current instruments. CTA will comprise several tens of Imaging Atmospheric Cherenkov…
In this paper, an opto-thermal analysis of a moderately heated lightweighted solar telescope mirror is carried out using 3D finite element analysis (FEA). A physically realistic heat transfer model is developed to account for the radiative…