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Related papers: Five-years Altitude Statistics of Noctilucent Clou…

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We suggest the procedure of building the maps of noctilucent clouds (NLC) zonal and meridional velocity, mean altitude and particle size based on three-color photometry by identical all-sky RGB-cameras separated by 115 km in a…

Atmospheric and Oceanic Physics · Physics 2023-12-15 Oleg S. Ugolnikov

The simple 3-D radiative transfer model in the atmosphere of the Earth is built for numerical comparison of direct solar radiation and limb scattering background at the definite layer during the deep twilight period at the middle and upper…

Atmospheric and Oceanic Physics · Physics 2025-09-05 Oleg S. Ugolnikov

During the summer season of 2025, noctilucent clouds (NLC) were observed at the latitudes 55-60N from the late May until the late August. A distinct 5-day periodicity in their occurrence emerged following the summer solstice. Analysis of…

Noctilucent or polar mesospheric clouds have become visually brighter and occurred more frequently during the recent years and decades. The study of possible reasons and relations with climate changes requires data on long-time trends of…

Atmospheric and Oceanic Physics · Physics 2021-12-08 Oleg S. Ugolnikov

The article deals with the analysis of color distribution in noctilucent clouds (NLC) in the sky based on multi-wavelength (RGB) CCD-photometry provided with the all-sky camera in Lovozero in the north of Russia (68.0 deg N, 35.1 deg E)…

Atmospheric and Oceanic Physics · Physics 2017-09-27 Oleg S. Ugolnikov , Alexey A. Galkin , Sergey V. Pilgaev , Alexey V. Roldugin

A method for measuring the altitude and particle size of noctilucent clouds, based on positioning and photometry from wide-angle three-color cameras, has been developed to determine the three velocity components, particle radius, and its…

Atmospheric and Oceanic Physics · Physics 2026-05-22 Oleg S. Ugolnikov , Olga Yu. Golubeva , Egor O. Ugolnikov

Mesospheric structures identical to summer noctilucent clouds were observed during the nights of December 17-19, 2024 in Siberian Russia. Basing on the available photo data, the mean altitude of the clouds 70.1+-1.5 km was measured by…

Atmospheric and Oceanic Physics · Physics 2025-01-30 Oleg S. Ugolnikov

Wide-field polarization measurements of the twilight sky background during the several nights with bright and extended noctilucent clouds in central and northern Russia in 2014 and 2015 are used to build the phase dependence of degree of…

Atmospheric and Oceanic Physics · Physics 2016-05-25 Oleg S. Ugolnikov , Igor A. Maslov , Boris V. Kozelov , Janna M. Dlugach

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…

Instrumentation and Methods for Astrophysics · Physics 2023-05-09 Jing Xu , Guo-jie Feng , Guang-xin Pu , Le-tian Wang , Zi-Huang Cao , Li-Qing Ren , Xuan Zhang , Shu-guo Ma , Chun-hai Bai , Ali Esamdin , Jian Li , Yuan Tian , Zheng Wang , Yong-heng Zhao , Jian-rong Shi

This paper presents a novel method for real-time nighttime cloud detection, tracking, and prediction using all-sky cameras, aimed at enhancing the efficiency of ground-based robotic telescopes. Ground-based telescopes are vulnerable to…

Instrumentation and Methods for Astrophysics · Physics 2025-07-30 Sebastian Buntin , Chris M. Copperwheat , Helen E. Jermak

The Northern Sky Variability Survey (NSVS) is a temporal record of the sky over the optical magnitude range from 8 to 15.5. It was conducted in the course of the first generation Robotic Optical Transient Search Experiment (ROTSE-I) using a…

Measuring the brightness of the night sky has become an increasingly important topic in recent years, as artificial lights and their scattering by the Earths atmosphere continue spreading around the globe. Several instruments and techniques…

We describe a system for rapidly measuring the brightness of the night sky using a mosaic of CCD images obtained with a low-cost automated system. The portable system produces millions of independent photometric measurements covering the…

Astrophysics · Physics 2009-11-13 D. M. Duriscoe , C. B. Luginbuhl , C. A. Moore

Extensive aircraft cloud physical observations made in more than 2000 tropical cumulus clouds indicated new observational evidence viz., (1) horizontal structure of the air flow inside the cloud has consistent variations with successive…

General Physics · Physics 2007-05-23 A. Mary Selvam , A. S. Ramachandra Murty

A sequence of very bright noctilucent clouds (NLC) was observed in central Russia during the last decade of June, 2018. It followed the meteorite impact 300 km southwards from Moscow in the morning of June 21. Polarization measurements of…

Atmospheric and Oceanic Physics · Physics 2020-01-08 Oleg S. Ugolnikov , Igor A. Maslov

Imaging the atmosphere using ground-based sky cameras is a popular approach to study various atmospheric phenomena. However, it usually focuses on the daytime. Nighttime sky/cloud images are darker and noisier, and thus harder to analyze.…

Computer Vision and Pattern Recognition · Computer Science 2017-05-31 Soumyabrata Dev , Florian M. Savoy , Yee Hui Lee , Stefan Winkler

The satellite imagery classification task is fundamental to spatial knowledge discovery. Several image classification methods are used to create standardized Land use and Land cover (LULC) maps, which facilitate research on spatial and…

Computers and Society · Computer Science 2020-05-04 Deepank Verma , Arnab Jana

The All Sky Camera (ASC) was developed as an universal device for a monitoring of the night sky quality and night sky background measurement. ASC system consists of an astronomical CCD camera, a fish eye lens, a control computer and…

Instrumentation and Methods for Astrophysics · Physics 2014-02-20 Dusan Mandat , Miroslav Pech , Miroslav Hrabovsky , Petr Schovanek , Miroslav Palatka , Petr Travnicek , Michael Prouza , Jan Ebr

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…

Astrophysics · Physics 2009-11-11 Lior Shamir , Roberj J. Nemiroff

We summarize methods and plans to monitor and calibrate photometric observations with our autonomous, robotic network of 2m, 1m and 40cm telescopes. These are sited globally to optimize our ability to observe time-variable sources. Wide…

Instrumentation and Methods for Astrophysics · Physics 2013-01-18 A. J. Pickles , W. E. Rosing
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