The Fourier transform of a dataset apodised with a window function is known as the Gabor transform. In this paper we extend the Gabor transform formalism to the sphere with the intention of applying it to CMB data analysis. The Gabor coefficients on the sphere known as the pseudo power spectrum is studied for windows of different size. By assuming that the pseudo power spectrum coefficients are...

An all-sky cloud monitoring system that generates relative opacity maps over many of the world’s premier astronomical observatories is described. Photometric measurements of numerous background stars are combined with simultaneous sky brightness measurements to differentiate thin clouds from sky glow sources such as air glow and zodiacal light. The system takes a continuous pipeline of all-sky ...

Realistic rendering of sky scene is important in virtual environment. Traditional methods are mostly based on skybox, thus failing to realistically simulate the change of sky scene under different weathers and conditions. In this paper, a new sky light model under different weathers for virtual environment is proposed. We first analyze the atmosphere characters of sky scene, and calculate the l...

We study asymptotic behavior of the global attractors to the Boussinesq system for Rayleigh-B enard convection at large Prandtl number. In particular, we show that the global attractors to the Boussinesq system for Rayleigh-B enard convection converge to that of the in nite Prandtl number model for convection as the Prandtl number approaches in nity. This o ers partial justi cation of the in ni...

In the course of the comprehensive CFRS redshift survey to I AB = 22.5 (see Lilly et al, these proceedings) with the CFHT MOS/SIS spectrograph, we have observed ∼25 field galaxies with z > 1. However, it is clear that almost an equal number, predominantly red galaxies, have likely been missed largely because of limitations in the observed wavelength range. The properties of the observed galaxie...

introduction thermal infrared integrated dust index (tiidi) is one of indices that is presented in this direction. the index operates based on four brightness temperature difference including wavelengths 3.7, 8.6, 11 and 12 micrometer. according to the studies, btd (bt12-bt11) is used for cloud detection. btd (bt8.6-bt11) is the index for separation for dust from sandy surface and btd (bt3.7-bt...

Assuming a simple pyrheliometric station model, an equation is derived relating the amount of insolation Q from a sky whose fraction C is covered by clouds, to the insolation &c, arriving at the same surface from a cloudless sky. The equation is of the form

We have started a search for High Redshift Radio Galaxies (HZRGs) in an area covering 7 sr by selecting a sample of Ultra Steep Spectrum (USS) sources with a low flux density cut-off S1400 > 10 mJy and a steep spectral index cut-off of α < −1.3 (S ∝ ν) from the WENSS, NVSS and TEXAS surveys. Our first results for 27 sources show that we are almost twice as effective in finding HZRGs than than s...

Estimates of solar irradiance at the earth’s surface from satellite observations are useful for planning both the deployment of distributed photovoltaic systems and their integration into electricity grids. In order to use surface solar irradiance from satellites for these purposes, validation of its accuracy against ground observations is needed. In this study, satellite estimates of surface s...

Nine different global models with detailed aerosol modules have independently produced instantaneous direct radiative forcing due to anthropogenic aerosols. The anthropogenic impact is derived from the difference of two model simulations with prescribed aerosol emissions, one for present-day and one for pre-industrial conditions. The difference in the solar energy budget at the top of the atmos...