We present a novel algorithm for detection of sky areas in outdoor color images. In contrast to sky detectors in literature that detect only blue, cloudless sky we intend to detect all sorts of sky, i.e. blue, clouded and partially clouded sky. Our approach is based on the analysis of color, position, and shape properties of color homogeneous spatially connected regions detected by the CSC. An ...

The Aladin interactive sky atlas, developed at CDS, is a service providing simultaneous access to digitized images of the sky, astronomical catalogues, and databases. The driving motivation is to facilitate direct, visual comparison of observational data at any wavelength with images of the optical sky, and with reference catalogues. The set of available sky images consists of the STScI Digitiz...

This paper demonstrates the use of High Dynamic Range (HDR) fisheye images of the sky dome in lighting simulations. The objective is to improve the accuracy of simulations with site specific sky conditions. The luminance information stored at a pixel level in an HDR photograph is used to light the simulated environment through an Image Based Rendering (IBR) technique. The results show that imag...

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We apply the sky brightness modelling technique introduced and developed by Roy Garstang to high-resolution DMSP-OLS satellite measurements of upward artificial light flux and to GTOPO30 digital elevation data in order to predict the brightness distribution of the night sky at a given site in the primary astronomical photometric bands for a range of atmospheric aerosol contents. This method, ba...

This paper proposes a method for constructing an experimental power beam pattern (PB) of RATAN-600 based on the sample of NVSS sources observed in the process of a deep sky survey near local zenith. The data obtained from observations of radio sources at λ7.6 cm in nine bands of the survey (the 2002 and 2003 sets) are used to construct vertical PB of the telescope at rather large offsets from t...

A recent model of celestial e-vector analysis by the bee assumes that polarization information is transformed into modulation of perceived brightness while the bee scans the sky by rotating its field of view. It is shown that the suggested simple strategy to read compass information from the polarization pattern of the sky in natural conditions can work only in a part of the sky close to the ze...

The Two-Point Angular Correlation Function is a standard analysis tool used to study angular anisotropies. Since BATSE’s sky exposure (the angular sampling of gamma-ray bursts) is anisotropic, the TPACF should at some point identify anisotropies in BATSE burst catalogs due to sky exposure. The effects of BATSE sky exposure are thus explored here for BATSE 3B and 4B catalogs. Sky-exposure effect...

An important parameter that defines the effectiveness and efficiency of any optical or infrared sky survey is the atmospheric characteristics of the observing site. Of prime importance is the sky spectral brightness, which determines the sensitivities and the observing time required to complete a particular survey. This paper presents observations of the near-infrared sky spectral brightness me...