Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 90 for “"Radio astronomy"”.
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A scalable packetised radio astronomy imager
Modern radio astronomy telescopes the world over require digital back-ends. The complexity of these systems depends on many site-specific factors, including the number of antennas, beams and frequency channels and the bandwidth to be processed. With the increasing popularity for ever larger …
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Neural cross-correlation for radio astronomy
Correlation engines are essential elements of most signal processing systems. Areas of applicability include image processing, speech synthesis and analysis, high energy physics, wireless and mobile communication systems, spread spectrum communication systems and even prosthetics. Finding cost …
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CARAD: Computer-aided Analysis of Radio Astronomy Data
Radio astronomy studies celestial objects by detecting their radio frequency emissions, enabling observation of phenomena invisible at other wavelengths. Next-generation telescopes generate unprecedented data volumes that challenge traditional analytical approaches. Manual inspection and classical …
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Adventures in radio astronomy instrumentation and signal processing
… analogue astronomical signals collected using radio telescopes. Modern radio telescopes have significant digital signal processing demands that are typically best met using custom processing engines implemented in Field Programmable Gate Arrays. These demands essentially stem from the …
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Bayesian model selection with applications to radio astronomy
… In the second part of this thesis, the Bayesian radio interferometry formalism of Lochner et al. (2015) is extended to take into account the gains of the antennae using the StEFCal algorithm, an important part of the calibration pipeline. Finally we study the case of a pair of sources and show …
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Fast online predictive compression of radio astronomy data
… is critical in the context of the MeerKAT radio telescope currently under construction in Southern Africa and Australia, which will produce data at rates up to 1 Petabyte every 20 seconds. The compression technique being investigated is based on predictive compression, which has proven …
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A Tri-Ridged Flared Horn for Radio Astronomy Applications
… an opportunity to check for viability in radio astronomy applications. To en-able such a study, an algorithm was developed to track and identify the modes in TRWG by using CST - a commercial three-dimensional electromagnetic analysis package. With the results of this algorithm, a modal …
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Genetic programming applied to RFI mitigation in radio astronomy
… research, the application of machine learning to radio astronomy was relatively new, with a limited number of publications on the subject. Genetic Programming had never been applied, and as such, was a novel approach to this challenging arena. Foundational to this body of research, the application …
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Real-time Adaptive Cancellation of Satellite Interference in Radio Astronomy
Radio astronomy is the science of observing the heavens at radio frequencies, from a few kHz to approximately 300 GHz. In recent years, radio astronomy has faced a growing interference problem as radio frequency (RF) bandwidth has become an increasingly scarce commodity. A programmable real-time …
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Development of a multi-frequency interferometer telescope for radio astronomy (MITRA)
Submitted in fulfilment of the academic requirements for the Degree Master of Engineering: Electrical Engineering, Durban University of Technology, Durban, South Africa, 2015.
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The development of new methods for high resolution radio astronomy imaging
… development of new methods for high resolution radio astronomy imaging in both of these areas. An implementation of the Maximum Entropy Method (MEM) suitable for multi-wavelength VLBI polarisation observations is presented and the advantage in resolution it possesses over the CLEAN algorithm is …
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Discrete Wavelet Methods for Interference Mitigation: An Application To Radio Astronomy
… how wavelets are effective in the suppression of Radio Frequency Interference (RFI) in the context of radio astronomy. This study begins with the design of a library of smooth orthogonal wavelets well suited to interference suppression. This is achieved through the use of a multi-parameter …
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Mixed Signals: Communication with the Alien in Cold War Radio Astronomy
This dissertation examines the development of radio astronomy and the search for and communication with extraterrestrial intelligence (CETI) from the 1950s through to the early 1980s, with the aim of understanding how these fields reflected the tensions, successes, and anxieties of Cold War …
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A digital spectral analysis technique and its application to radio astronomy
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering, 1963.
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Conceptual design of HADES a CubeSat conducting radio astronomy in lunar orbit
… to ionospheric cutoff and intense anthropogenic radio frequency interference. This thesis evaluates the feasibility of a lunar-orbiting 12U CubeSat designed to leverage the Moon’s far side as a natural shield against terrestrial and solar noise, targeting the detection of the global spectral …
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Accelerating software radio astronomy FX correlation with GPU and FPGA co-processors
… compute intensive sections of a frequency domain radio astronomy correlator using dedicated co-processors. Two co-processor implementations were made independently with one using reconfigurable hardware (Xilinx Virtex 4LXlOO) and the other uses a graphics processor (Nvidia 9800GT). The objective …
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X-band digitization systems aspects and filters for MeerKAT radio astronomy receiver
The MeerKAT Radio Telescope is a 64 element antenna array under construction in South Africa. This array will be used to observe radiation from celestial sources at radio frequencies. Once completed, this radio telescope will be the largest and most sensitive radio telescope in the Southern …
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Beamforming Techniques and Interference Mitigation Using a Multiple Feed Array for Radio Astronomy
<p>Radio frequency interference has become a large problem to radio astronomers. This thesis proposes the idea that radio frequency interference can be mitigated using a phased array feed in conjunction with a large reflector. A phased array feed would allow radio astronomers to observe fainter …
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Absolute Flux Density Measurement and Associated Instrumentation for Radio Astronomy below 100 MHz
… in the context of contemporary interest in radio astronomy and 21 cm cosmology in this frequency range. A new active antenna system and measurement technique were developed to facilitate these measurements. The antennas are simple, thin dipoles, allowing for accurate characterization. …
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High-Speed Data Acquisition and FPGA Detected Pulse Blanking System for Interference Mitigation in Radio Astronomy
<p>Radio astronomy is the discipline dedicated to the study of celestial emissions in the radio band from a few MHz to 300 GHz. In recent years, spurious emissions from man-made devices that operate at these frequencies have made detection of astronomical signals difficult. These harmful RF …
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