Related papers: Satellite characterization of four interesting sit…
Comparing the number of clear nights (cloud free) available for astronomical observations is a critical task because it should be based on homogeneous methodologies. Current data are mainly based on different judgements based on observer…
The fraction of available telescope time is one of the most important requirements for selecting astronomical sites affecting the performance of ground based telescopes. A quantitative survey of clouds coverage at La Palma and Mt.Graham is…
In this study we describe an innovative method to determine potential sites for optical and infrared astronomical observations in the Andes region of northern South America. The method computes the Clear sky fraction (CSF) from…
The analysis of the night cloud cover is very important for astronomical observation in real time, considering a typical observation time of about 15 minutes, and to have a statistics of the night cloud cover. In this paper we use the SQM…
San Pedro M\'artir in the Northwest of Mexico is the site of the Observatorio Astron\'omico Nacional. It was one of the five candidates sites for the Thirty Meter Telescope, whose site-testing team spent four years measuring the atmospheric…
We present for the first time a new method to estimate the seeing using remote sounding from the IR night time data of the GOES 12 satellite. We discuss the derived correlation between the ground data and the satellite derived values from…
The clarity of nights is the major factor that should be carefully considered for optical/infrared astronomical observatories in site-testing campaigns. Cloud coverage is directly related to the amount of time available for scientific…
The brightness of the moonless night sky above La Palma was measured on 427 CCD images taken with the Isaac Newton and Jacobus Kapteyn Telescopes on 63 nights during 1987 - 1996. The median sky brightness at high elevation, high galactic…
We report measurements from which we determine the spatial structure of the lunar contribution to night sky brightness, taken at the LSST site on Cerro Pachon in Chile. We use an array of six photodiodes with filters that approximate the…
We present a characterization of the main properties of the night-sky at the Calar Alto observatory for the time period between 2004 and 2007. We use optical spectrophotometric data, photometric calibrated images taken in moonless observing…
Nighttime visible-light sky brightness and transparency are reported for the Polar Environment Research Laboratory (PEARL), located on a 610-m high ridge near the Eureka research station, on Ellesmere Island, Canada. Photometry of Polaris…
Sierra Negra, one of the highest peaks in central Mexico, is the site of the Large Millimeter Telescope. We describe the first results of a comprehensive analysis of the weather data measured in situ from October 2000 to February 2008 to be…
The fraction of observable nights is an essential parameter for selecting astronomical sites. In recent years, meteorological satellite data have played an essential role in recognising and providing statistics of observable nights. We…
Cloud cover plays a pivotal role in assessing observational conditions for astronomical site-testing. Except for the fraction of observing time, its fragmentation also wields a significant influence on the quality of nighttime sky clarity.…
We present the first results of the site testing performed at Mt.~Shatdzhatmaz at Northern Caucasus, where the new Sternberg astronomical institute 2.5-m telescope will be installed. An automatic site monitor instrumentation and…
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…
We present optical UBVRI zenith night sky brightness measurements collected on eighteen nights during 2013--2016 and SQM measurements obtained daily over twenty months during 2014--2016 at the Observatorio Astronomico Nacional on the Sierra…
The observation of celestial objects is a fundamental activity in astronomy. Ground-based and space telescopes are used to gather electromagnetic radiation from space, allowing astronomers to study a wide range of celestial objects and…
We report a study of cloud cover over Indonesia based on meteorological satellite data, spanning over the past 15 years (from 1996 to 2010) in order to be able to select a new astronomical site capable to host a multi-wavelength…
The effect of satellite constellations on observations in the visible and IR domains is estimated, considering 18 constellations in development by SpaceX, Amazon, OneWeb, and others, with over 26,000 satellites, constituting a…