Searched for: subject:"radio%5C+astronomy"
(1 - 15 of 15)
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Mok, S. (author), Guo, J. (author), Gill, E.K.A. (author), Rajan, R.T. (author)
Orbiting Low Frequency Array for Radio Astronomy (OLFAR) is a radio astronomy mission that has been studied since 2010 by several Dutch universities and research institutes. The mission aims at producing sky maps by collecting cosmic signals at ultra-low wavelengths regimes, below the 30 MHz frequency band. A satellite swarm comprising more than...
conference paper 2020
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van 't Hoff, Jurriaan (author)
In the field of radio astronomy the Ultra-Long Wavelength (f < 30MHz) band is unique, it has been studied for nearly a century yet it is still almost completely uncharted. Due to the reflective properties of Earth's ionosphere this band is nearly completely inaccessible for ground-based observatories, which can only receive frequencies down...
master thesis 2020
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Bentum, M. J. (author), Verma, M. K. (author), Rajan, R.T. (author), Boonstra, A. J. (author), Verhoeven, C.J.M. (author), Gill, E.K.A. (author), van der Veen, A.J. (author), Falcke, H. (author), Wolt, M. Klein (author), Monna, B. (author), Engelen, S. (author), Rotteveel, J. (author), Gurvits, L. (author)
The past two decades have witnessed a renewed interest in low frequency radio astronomy, with a particular focus on frequencies above 30 MHz e.g., LOFAR (LOw Frequency ARray) in the Netherlands and its European extension ILT, the International LOFAR Telescope. However, at frequencies below 30 MHz, Earth-based observations are limited due to a...
journal article 2020
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Manchanda, Prabhav (author)
Space launches have been steadily increasing over the years as satellites are being used in various applications such as communication, military, and science. The costs of launching satellites are still high and depend on the dimensions and weight of the satellite. With the advancement in the field of autonomous robotics and telecommunications,...
master thesis 2019
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Tang, Yajie (author)
Radio astronomy image formation can be treated as a linear inverse problem. However, due to physical limitations, this inverse problem is ill-posed. To overcome the ill-posedness, side information should be involved. Based on the sparsity assumption of the sky image, we involve l1-regularization. We formulate the image formation problem into a...
master thesis 2019
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Rajan, R.T. (author), Sundaramoorthy, P.P. (author), Vertegaal, C.J.C. (author), Montagne, A.J.M. (author), Karunanithi, V. (author), Verma, Maneesh (author), Bentum, M (author), Verhoeven, C.J.M. (author)
The frequency range between 0.3 and 30 MHz remains one of the last unexplored frequency ranges in radio astronomy. However, Earth-based observations at these wavelengths are severely impeded, due to man-made radio frequency interference (RFI) and atmospheric opacity. To overcome this impediment, various space-based radio astronomy studies have...
conference paper 2019
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Mouri Sardarabadi, A. (author), van der Veen, A.J. (author), Koopmans, Leon V.E. (author)
Having an accurate calibration method is crucial for any scientific research done by a radio telescope. The next generation radio telescopes such as the Square Kilometre Array (SKA) will have a large number of receivers which will produce exabytes of data per day. In this paper we propose new direction-dependent and independent calibration...
conference paper 2018
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Rajan, R.T. (author)
doctoral thesis 2016
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Mouri Sardarabadi, A. (author)
The search for the answer to one of the most fundamental scientific questions, “How was the universe formed?”, requires us to study very weak radio signals from the early universe. In the last eighty years, radio astronomers have been able to use radio frequency observations for significant discoveries such as quasars, super massive Black Holes...
doctoral thesis 2016
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Naghibzadeh, S. (author), Mouri Sardarabadi, A. (author), van der Veen, A.J. (author)
Image formation using the data from an array of sensors is a familiar problem in many fields such as radio astronomy, biomedical and geodetic imaging. The problem can be formulated as a least squares (LS) estimation problem and becomes ill-posed at high resolutions, i.e. large number of image pixels. In this paper we propose two regularization...
conference paper 2016
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Rajan, R.T. (author), Boonstra, A.J. (author), Bentum, M. (author), Klein-Wolt, M. (author), Belien, F. (author), Arts, M. (author), Saks, N. (author), Van der Veen, A.J. (author)
The past decade has seen the advent of various radio astronomy arrays, particularly for low-frequency observations below 100 MHz. These developments have been primarily driven by interesting and fundamental scientific questions, such as studying the dark ages and epoch of re-ionization, by detecting the highly red-shifted 21 cm line emission....
journal article 2015
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Vermeiden, H. (author)
Investigation of the feasibility of using translunar Lagrange point orbits for low-frequency radio wave astronomy, in particular for Orbiting Low-Frequency Antennas fro Radio astronomy (OLFAR). Furthermore suggesting swarm and orbit configurations that lead to the best possible results.
master thesis 2014
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Mimoun, D. (author), Wieczorek, M.A. (author), Gurvits, L. (author)
Farside Explorer is a proposed Cosmic Vision medium-size mission to the farside of theMoon consisting of two landers and an instrumented relay satellite. The farside of the Moon is a unique scientific platform in that it is shielded from terrestrial radio-frequency interference, it recorded the primary differentiation and evolution of the Moon,...
journal article 2012
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Boonstra, A.J. (author), Van der Tol, S. (author)
The Low Frequency Array (LOFAR) is a radio telescope currently being designed. Its targeted observational frequency window lies in the range of 10–250 MHz. In frequency bands in which there is interference, the sensitivity of LOFAR can be enhanced by interference mitigation techniques. In this paper we demonstrate spatial filtering capabilities...
journal article 2005
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Boonstra, A.J. (author)
The next generation of radio telescopes is expected to be one to two orders of magnitude more sensitive than the current generation. Examples of such new telescopes are the Low Frequency Array (LOFAR), currently under construction in the Netherlands, and the Square Kilometer Array (SKA), currently in a concept study phase. Another trend is that...
doctoral thesis 2005
Searched for: subject:"radio%5C+astronomy"
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