Results 21 to 30 of about 493 (197)

New discoveries on astronomical orientation of Inca site in Ollantaytambo, Peru

Geoinformatics FCE CTU, 2015
This paper deals with astronomical orientation of Incas objects in Ollantaytambo, which is located about 35 km southeast from Machu Picchu, about 40 km northwest from Cusco, and lies in the Urubamba valley.
Karolína Hanzalová, Jaroslav Klokočník, Jan Kostelecký   +2 more
doaj   +1 more source

THE ROLE OF ASTRO-GEODETIC IN PRECISE GUIDANCE OF LONG TUNNELS [PDF]

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2015
One of prime aspects of surveying projects is guidance of paths of a long tunnel from different directions and finally ending all paths in a specific place. This kind of underground surveying, because of particular condition, has some different points in
M. Mirghasempour, A. Y. Jafari
doaj   +1 more source

Servo control system design for square kilometre array radio telescope [PDF]

Journal of Hebei University of Science and Technology
To construct the world’s largest aperture radio telescope and equip the system with the highest sensitivity and image resolution, a new control system was developed for the 15-meter offset SKA antenna.
Qiang ZHANG, Yifan ZHANG, Xuguang GENG
doaj   +1 more source

Research on magnetic declination in Lithuanian territory

Aviation, 2008
Magnetic declination is the angle between the planes of the astronomic and magnetic meridians. Magnetic declination is used in navigation, geophysics, geodesy, cartography, geology, and other fields.
Romuald Obuchovski, Petras Petroškevičius, Arūnas Būga   +2 more
doaj   +1 more source

A correction method of encoder bias in satellite laser ranging system

Geodesy and Geodynamics, 2013
In a satellite laser ranging telescope system, well-aligned encoders of the elevation and azimuth axes are essential for tracking objects. However, it is very difficult and time-consuming to correct the bias between the absolute-position indices of the ...
Wang Peiyuan, Zhu Wei, Zou Tong, Guo Tangyong   +3 more
doaj   +1 more source

Enhancing the Capability of a Ground-Based Optical Telescope for Thai National Space objects Observation ^†

Proceedings, 2020
Nowadays, the space operations environment have to face with space safety problems because of the growing of space debris in resident of space objects (RSOs) that can cause a catastrophic collision. In order to prevent debris-related risks in operational
Peerapong Torteeka, Pakawat Prasit, Kritsada Palee, Apichart Leckngam, Patcharin Kamsing   +4 more
doaj   +1 more source

Daylight Observations of Venus with Naked Eye in the Goryeosa [PDF]

Journal of Astronomy and Space Sciences, 2017
In this paper, we investigate the observations of Venus in daytime that are recorded in the Goryeosa (History of the Goryeo Dynasty, A.D. 918-1392). There are a total of 167 accounts of such observations in this historical book, spanning a period of ...
Ki-Won Lee
doaj   +1 more source

Alkylthienyl Side Groups in Conjugated Polymers Enable Localization of π Electron Density and Facilitate Efficient Hole Transfer

Advanced Science, EarlyView.
Resonance Raman spectroscopy is used in combination with other spectroscopic and morphology characterization techniques to unveil the mechanistic origin of the shift in synthetic strategy to alkylthienyl peripheral groups for high‐performing organic photovoltaics.
Hristo Ivov Gonev, Daniel G. Congrave, Junjun Guo, Jose Marin‐Beloqui, Max Allen, David Bacon, Ankita Kumari, Mohammad Saeed Shadabroo, He Zhu, Dibyajyoti Ghosh, Rachel C. Kilbride, Safa Shoaee, Hugo Bronstein, Tracey M. Clarke   +13 more
wiley   +1 more source

LIGHT POLLUTION IN LEO-SATELLITE TRACKING

Odessa Astronomical Publications, 2016
Because of the high level of the light pollution in Odessa city, only the observations of LEO (low Earth orbit)-satellites are performed in the main office of the Astronomical observatory of Odessa National University named after I.I. Mechnikov.
L. S. Shakun, V. I. Marsakova, T. A. Golubovskaya, S. S. Terpan, S. M. Melikyants, E. A. Korobeynikova   +5 more
doaj   +1 more source

Emerging of Anomalous Higher‐Order Topological Phases in Altermagnet/Topological Insulator Heterostructure by Floquet Engineering

Advanced Science, EarlyView.
We combine altermagnet with topological insulators and subject the structure to Floquet driving. This breaks time‐reversal symmetry and creates a new type of higher‐order topological insulator. Its key feature is the emergence of programmable “0/π‐corner modes” that can be controlled by magnetic field direction, offering a novel dynamic platform for ...
Donghao Wang, Arnob Kumar Ghosh, Yongchun Tao, Fusheng Ma, Cheng Song   +4 more
wiley   +1 more source