14 papers · ranked by Valyu relevance
Roger Angel
The proposed lunar telescope for optical and infrared astronomy aims at very large aperture, 600 m2, at a fundable cost. It comprises an array of 18 separate telescopes, each of 6.5 m aperture. The 200 m diameter array will be located within 1/2° (15 km) of a lunar pole on approximately level ground, with a perimeter…
Ryker W. Eads, J. Roger P. Angel
A 20 m space telescope is described with an unvignetted 1° field of view-a hundred times larger in area than fields of existing space telescopes. Its diffraction-limited images are a hundred times sharper than from wide-field ground-based telescopes and extend over much if not all the field, 40 arcmin diameter at 500…
Huiru Ji, Lujia Zhao, Zichao Fan, Rundong Fan + 6 more
'Hao Tan' 'Zhiyu Jiang' 'Donglin Ma' 'Lei Huang'] Space-based gravitational wave (GW) detection employs the Michelson interferometry principle to construct ultra-long baseline laser interferometers in space for detecting GW signals with a frequency band of 10−4-1 Hz. The spaceborne telescope, as a core component…
Léon V. E. Koopmans, Rennan Barkana, Mark Bentum, Gianni Bernardi + 26 more
The Dark Ages and Cosmic Dawn are largely unexplored windows on the infant Universe (z ~ 200-10). Observations of the redshifted 21-cm line of neutral hydrogen can provide valuable new insight into fundamental physics and astrophysics during these eras that no other probe can provide, and drives the design of many…
Haisong Wei, Haixiang Hu, Feng Yan, Xindong Chen + 3 more
'Donglin Xue' 'Xuejun Zhang'] To test large-aperture space optical systems in a simple and highly efficient manner, the scanning Hartmann test (SHT) has been used to measure the sub-aperture wavefront slopes of optical systems by scanning with a collimated beam followed by retrieval of the overall wavefront form.…
Guoliang Peng, Lihui Jiang, Xiaohui Tao, Yan Zhang + 3 more
'Jesmin Farzana Khan' 'Mandoye Ndoye'] The next generation phased array radio telescopes, such as the Square Kilometre Array (SKA) low frequency aperture array, suffer from RF interference (RFI) because of the large field of view of antenna element. The classical station beamformer used in SKA-low is resource efficient…
Bhaskar Ahuja, Luca Gentile, Ajeet Kumar, Marco Martorella + 3 more
'Xiaofei Zhang' 'Jianfeng Li' 'Wei Liu'] The growing population of space debris poses significant risks to operational satellites and future space missions, necessitating innovative and efficient tracking solutions. Ground-based radar for space surveillance has been a central area of research since the early Space Age…
Giampaolo Pisano, Jason Austermann, James Beall, Nils Halverson + 5 more
'Johannes Hubmayr' 'Gregory Jaehnig' 'Christopher M. McKenney' 'Benjamin Raymond' 'Aritoki Suzuki'] The high sensitivity requirements set by future cosmic microwave background instruments are pushing the current technologies to produce highly performant focal plane arrays with thousands of detectors. The coupling of…
Weijie Zhao
The Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) is the world's largest and most sensitive filled-aperture single-dish radio telescope, with a dish diameter of 500 meters and an effective illuminated diameter of 300 meters. This ‘big eye looking into the sky’ is located in a natural karst rock basin in…
Ling Xin
The network can continuously track space weather from the Sun's surface to interplanetary space and Earth's atmosphere.
Adelaide Ladu, Luca Schirru, Mauro Pili, Gian Paolo Vargiu + 6 more
'Francesco Gaudiomonte' 'Federico Perini' 'Andrea Melis' 'Raimondo Concu' 'Matteo Murgia' 'Manuel Sierra Castañer'] Low-frequency aperture arrays represent sensitive instruments to detect signals from radio astronomic sources situated in the universe. In Italy, the Sardinia Aperture Array Demonstrator (SAAD) consists…
P. Rosati, S. Basa, A. W. Blain, E. Bozzo + 36 more
'L. Christensen' 'A. Ferrara' 'A. Gomboc' 'P. T. O’Brien' 'J. P. Osborne' 'A. Rossi' 'F. Schüssler' 'M. Spurio' 'N. Stergioulas' 'G. Stratta' 'L. Amati' 'S. Casewell' 'R. Ciolfi' 'G. Ghirlanda' 'S. Grimm' 'D. Guetta' 'J. Harms' 'E. Le Floc’h' 'F. Longo' 'M. Maggiore' 'S. Mereghetti' 'G. Oganesyan' 'R. Salvaterra' 'N.…
Irene Merino-Fernandez, Sunil L. Khemchandani, Javier del Pino, Jose Saiz-Perez + 2 more
'Jose Saiz-Perez' 'Tiago Varum' 'Joao Nuno Matos'] Nowadays, mega-constellations of Low Earth Orbit (LEO) satellites have become increasingly important to provide high-performance Internet access with global coverage. This paper provides an updated comparison of four of the largest LEO mega-constellations: Telesat…
David Krutz, Rupert Müller, Uwe Knodt, Burghardt Günther + 16 more
Whether for identification and characterization of materials or for monitoring of the environment, space-based hyperspectral instruments are very useful. Hyperspectral instruments measure several dozens up to hundreds of spectral bands. These data help to reconstruct the spectral properties like reflectance or emission…