Related papers: Measuring Tianlai's primary beam using sky model
The Sky Brightness Monitor (SBM) is an important instrument to measure the brightness level for the sky condition, which is a critical parameter for judging a site for solar coronal observations. In this paper we present an automatic method…
[NOTE: Previous versions of this paper (both on astro-ph and published in Phys. Rev. D) contain results that are in error. The power spectra C_l were normalized incorrectly by a factor of 2 pi. All observing times in detector-years in those…
We present the science case for surveys with the Tianlai dish array interferometer tuned to the $\left[ 1300, 1400 \right] \mathrm{MHz}$ frequency range. Starting from a realistic generation of mock visibility data according to the survey…
Large radio telescopes in the 21st century such as the Low-Frequency Array (LOFAR) or the Murchison Widefield Array (MWA) make use of phased aperture arrays of antennas to achieve superb survey speeds. The Square Kilometer Array low…
The investigation of $e \gamma \to \nu W$ process is crucial for a possible high energy $e \gamma$ or $\gamma \gamma$ collider since it offers the possibility for both new physics discovery and precision measurements. The polarization of…
Polarimetric observations of the twilight sky are effective for the investigations of scattering properties of the atmosphere at different altitudes. Modern computer technique allows to reduce the influence of multiple scattering on the…
We investigate the polarization patterns from the moonlit sky as observed from the European Southern Observatory at Cerro Paranal. The moonlit sky background can be significant in astronomical observations and thus be a source of…
We obtain iso-spectral Euler-Bernoulli beams by using factorization and Lie symmetry techniques. The canonical Euler-Bernoulli beam operator is factorized as the product of a second-order linear differential operator and its adjoint. The…
The one-meter telescope at Weihai Observatory of Shandong University is an f/8 Cassegrain telescope. Three sets of filters, including Johnson--Cousins UBVRI, Sloan Digital Sky Survey u$'$g$'$r$'$i$'$z$'$ and Str\"{o}mgren uvby, are…
Tianyu telescope, an one-meter robotic optical survey instrument to be constructed in Lenghu, Qinghai, China, is designed for detecting transiting exoplanets, variable stars and transients. It requires a highly automated, optimally…
In optical astronomical telescopes, the primary baffle is a tube-like structure centering in the hole of the primary mirror and the vanes usually locate inside the baffle, improving the suppression of stray light. They are the most common…
Context: Being part of the brightest solar-like stars, and close solar analogues, the 16 Cygni system is of great interest to the scientific community and may provide insight into the past and future evolution of our Sun. It has been…
Ground-based whole sky cameras are extensively used for localized monitoring of clouds nowadays. They capture hemispherical images of the sky at regular intervals using a fisheye lens. In this paper, we propose a framework for estimating…
The measurement of the solar diameter is introduced in the wider framework of solar variability and of the influences of the Sun upon the Earth's climate. Ancient eclipses and planetary transits would permit to extend the knowledge of the…
Beamforming-capable antenna arrays overcome the high free-space path loss at higher carrier frequencies. However, the beams must be properly aligned to ensure that the highest power is radiated towards (and received by) the user equipment…
Patterning the front side of an ultra-thin crystalline silicon (c Si) solar cell helps keeping the energy conversion efficiency high by compensating for the light absorption losses. A super-Gaussian mathematical expression was used in order…
The Tianlai project is a 21cm intensity mapping experiment aimed at detecting dark energy by measuring the baryon acoustic oscillation (BAO) features in the large scale structure power spectrum. This experiment provides an opportunity to…
We describe techniques concerning wavelength calibration and sky subtraction to maximise the scientific utility of data from tunable filter instruments. While we specifically address data from the Optical System for Imaging and low…
The shift to the radiative near field region due to large antenna arrays necessitates beamforming that accounts for both angle and range, evolving mobility management into a joint angular range tracking challenge. Conventional schemes rely…
The diameter of the Sun has been measured using Baily's beads during central eclipses, observed with portable telescopes. A blend of tiny emission lines produced in the first several hundred kilometers above the photosphere gives a light…