The Milagro Gamma Ray Observatory is the world’s first large-area water Cherenkov detector capable of continuously monitoring the sky at TeV energies. Located in the mountains of northern New Mexico, Milagro will perform an all sky survey of the Northern Hemisphere at energies between 250 GeV and 50 TeV. With a high duty-cycle ( 100%), large detector area ( 5000m), and wide field-of-view ( 1 sr...

Aperture array interferometers, such as that proposed for the Square Kilometre Array (SKA), will see the entire sky, hence the standard approach to simulating observed visibilities will not be applicable since it relies on a tangent plane approximation that is only valid for small fields of view. We derive the harmonic representation of the visibility function observed by an aperture array inte...

The Australian National University’s SkyMapper telescope is amongst the first of a new generation of dedicated wide-field survey telescopes. Featuring a 5.7 deg field-of-view Cassegrain imager and 268 Mega-pixel CCD array, its primary goal will be to undertake the Southern Sky Survey: a six color (uvgriz), six-epoch digital record of the entire southern sky. The survey will provide photometry f...

An imaging Stokes-vector polarimeter using liquid crystal variable retarders (LCVRs) has been built and calibrated. Operating in five bands from 450 to 700 nm, the polarimeter can be changed quickly between narrow (12 degrees ) and wide (approximately 160 degrees) fields of view. The instrument is designed for studying the effects of differing sky polarization upon the measured polarization of ...

Sky/cloud images obtained from ground-based sky-cameras are usually captured using a fish-eye lens with a wide field of view. However, the sky exhibits a large dynamic range in terms of luminance, more than a conventional camera can capture. It is thus difficult to capture the details of an entire scene with a regular camera in a single shot. In most cases, the circumsolar region is over-expose...

The formation and evolution of clouds are associated with their thermodynamical microphysical progress. Previous studies have been conducted to collect images using ground-based cloud observation equipment provide important characteristics information. However, most this cannot perform continuous observations during the day night, field view (FOV) is also limited. To address these issues, work ...

ABSTRACT Scintillation noise significantly limits high precision ground-based photometry of bright stars. In this paper, we present the first ever on-sky demonstration scintillation correction. The technique uses tomographic wavefront sensing to estimate spatial-temporal intensity fluctuations induced by altitude optical turbulence. With an altitudes and relative strengths turbulent layers abov...