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 47 for “"Radio Frequency Interference"”.
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The MeerKAT Radio Frequency Interference Environment
Radio signals from astronomical sources are extremely weak and easily distorted/- corrupted or overwhelmed by man-made radio signals such as cellphones, satellites, aircraft and telescope electronics. These Radio Frequency Interference (RFI) are increasingly threatening radio observatories due to …
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Machine Learning for Radio Frequency Interference Flagging
The field of radio frequency interference (RFI) flagging involves the identification of corrupted data within radio astronomy measurements. This work explores the application of supervised machine learning algorithms for RFI flagging, trained on real measurement data and simulated data with …
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Efficient estimation and mitigation for radio-frequency interference
… etc. Those noise sources can possibly introduce radio frequency interference (RFI) issues. In this dissertation, a transfer function based calculation method is proposed to estimate radio frequency interference (RFI) problems. The derived equations can clearly decompose the RFI problem into two …
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Radio Frequency Interference: Simulations for Radio Interferometry Arrays
Radio Frequency Interference (RFI) is a massive problem for radio observatories around the world. Due to the growth of telecommunications and air travel RFI is increasing exactly when the world's radio telescopes are increasing significantly in sensitivity, making RFI one of the most pressing …
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Near-field scanning study for radio frequency interference estimation
… techniques using near-fields scanning to do radio frequency interference (RFI) estimation. As the electronic products are becoming more and more complicated, the radio frequency (RF) receiver in the system is very likely interfered by multiple noise sources simultaneously. A method is …
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Coherent Mitigation of Radio Frequency Interference in 10-100 MHz
This dissertation describes methods of mitigating radio frequency interference (RFI) in the frequency range 10-100 MHz, developing and evaluating coherent methods with which RFI is subtracted from the afflicted data, nominally resulting in no distortion of the underlying signals. This approach is …
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Radio frequency interference and risk of damage for satellite servicing missions
… on its intended client, thereby causing interference or even damage to receiver components. It begins by examining the satellite servicing paradigm, and introducing as case studies two missions that are currently in development. Then the theory of coupling is presented, starting with an …
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Array Analysis of Radio Frequency Interference Cancelation Requirements for a Land Mine Detection System
… Unfortunately, NQR is highly succeptible to radio frequency interference (RFI). A significant contribution of this thesis is the development of a custom, experimental data acquisition system designed and built specifically for capturing RFI at frequencies significant to NQR land mine …
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The Development of a Small Scale Radio Astronomy Image Synthesis Array for Research in Radio Frequency Interference Mitigation
Radio astronomy synthesis imaging arrays are composed of many parabolic reflector antennas. These antennas are designed to be extremely sensitive to detect faint emissions from astronomical sources. Unfortunately, this also makes them susceptible to radio frequency interference (RFI) from man made …
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Radio frequency interference (RFI) modeling of complex modules in mobile devices and system-level modeling for transient ESD simulation
… papers, which cover the systematic modeling of radio-frequency-interference (RFI) and electro-static-discharge (ESD) problems happened in mobile devices.</p> <p>In the first paper, an averaging technique is developed, for phase resolved scanning over random fields generated by multiple …
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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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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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A Standalone High Frequency Receiver System
The High Frequency Receiver System (HFRS) is a mobile, autonomous, Linux-based RF recording system that is designed to pick up ionosonde sounding signals from 1—10 MHz. Systems are designed for quick deployment and capable of remaining deployed in the field for up to a month. The design motivation …
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Determination of the Parameter Limits for Artificial Non-random Microwave Signal Detection
… Intelligence (SETI) project, which can simulate radio frequency interference (RFI) and a buried ETI signal, will determine the limits of the signal-to-noise ratio (SNR) and false alarm threshold for identification of the signal after Doppler shifting. By running the model on a MicroVAX II …
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Using machine learning methods to aid scientists in laboratory environments
… of two projects, we discuss creating a real-time interference monitor for use at a radio observatory. We show how deep neural networks can be used to assist with the detection of radio-frequency interference around the site, and consider methods of unsupervised learning to identify patterns in the …
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Mitigation of Interference From Iridium Satellites by Parametric Estimation and Subtraction
Radio astronomy is the science of observing the universe at radio frequencies. In recent years, radio astronomy has faced a growing interference problem as radio frequency (RF) bandwidth has become an increasingly scarce commodity. Communication systems such as Earth orbiting communication …
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Time Blanking for GBT Data with RADAR RFI
The 1215 MHz to 1400 MHz band is important for radio astronomers to observe redshifted extragalactic hydrogen ionic (HI). Observations at these frequencies are complicated by radio frequency interference (RFI) from strong man-made transmissions such as the ARSR-3 Air Surveillance Radar. In this …
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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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Courting Serendipity: The Search for Transient Radio Signals
The transient radio sky remains a frontier of observational astronomy, not for lack of scientific promise, but for practical obstacles: terrestrial radio frequency interference (RFI) and limited computing power. Today, a confluence of new RFI mitigation techniques and computing power makes a …
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Thermal design and analysis of the SKA SA MeerKAT Digitiser
… venture attempting to build the world's largest radio telescope. Australia and South Africa (together with other African countries), will be host to the SKA site. Both countries are building pre-cursor radio telescopes to demonstrate their ability to successfully host the project. Square …
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