Instrumentation Commons^™

Applications Of Digital Filters In Radio Astronomy, Joseph William Kania

Graduate Theses, Dissertations, and Problem Reports

The radio sky spans tens of orders of magnitude in length, density, and time.
In this thesis, using novel filtering techniques and two different telescopes,
we investigate two tracers of cosmic structure: Baryon Acoustic Oscillations
(BAOs) and Fast Radio Bursts (FRBs). BAOs formed as the universe cooled
after the Big Bang. BAOs provide a fiducial length scale of the universe
throughout cosmic time and thus can be used to understand how the universe
is evolving. FRBs are very bright, short timescale, bursts of as-yet unknown
origin which occur uniformly on the sky at a rate of a few thousand per …

Impact Of Radio Frequency Interference And Real-Time Spectral Kurtosis Mitigation, Evan T. Smith

Graduate Theses, Dissertations, and Problem Reports

We catalog the ubiquity of Radio Frequency Interference (RFI) plaguing every modern radio telescope and investigate several ways to mitigate it in order to create better science-ready data products for astronomers. There are a myriad of possible RFI sources, including satellite uplinks and downlinks, cellular communications, air traffic radar, and natural sources such as lightning. Real-time RFI mitigation strategies must take these RFI characteristics into account, as the interfering signals can look significantly different at very high time and frequency resolutions.

We examine Spectral Kurtosis (SK) as a real-time statistical RFI detection method, and compare its flagging efficacy against simulated …

Inferential Statistics And Information Theoretical Measures: An Approach To Interference Detection In Radio Astronomy, Morgan R. Dameron

Graduate Theses, Dissertations, and Problem Reports

In a time when technology is rapidly growing, radio observatories are now able to expand their computational power to achieve higher receiver sensitivity power and a more flexible realtime computing approach to probe the universe for its composition and study new astronomical phenomena. This allows searches to go deeper into the universe, and results in the recording of massive quantities of observed data. At the same time, this increases the amount of radio frequency interference (RFI) found in the obtained observatory data. The high power of RFI easily masks the low power of extraterrestrial signals, making them hard to detect …

Pathfinding Fast Radio Bursts Localizations Using Very Long Baseline Interferometry, Pranav Rohit Sanghavi

Graduate Theses, Dissertations, and Problem Reports

Fast radio bursts (FRBs) are millisecond-duration, bright radio transients of extragalactic origin. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope’s CHIME/FRB instrument and other radio telescopes across the globe have detected hundreds of FRBs. Their origins are a mystery. Precise localization within the host is critical to distinguish between progenitor models. This can be achieved through Very Long Baseline Interferometry (VLBI). Until now, VLBI localizations have only been carried out in targeted follow-up observations of some repeating sources which comprise a small fraction of the FRBs.

For this work, an interferometric array of 6m dishes was constructed at the Green …

Transform Based Approaches For The Detection Of Astrophysical Signals, Marwan Mahfud Alkhweldi

Graduate Theses, Dissertations, and Problem Reports

Development of new algorithms for the detection of isolated astrophysical pulses is of interest to radio astronomers. Both Fast Radio Bursts (FRBs) and several Rotating Radio Transients (RRATs) were detected through the application of a single pulse search algorithm. The conventional approach to detect astronomical pulses requires an exhaustive search for the correct dispersion measure. Its accelerated versions involve signal processing in Fourier transform space.

In this dissertation, we present several new transform-based approaches for the detection and analysis of astrophysical signals with the latest being the most effective and advanced of all. It is implemented in several steps. First, …

Magnetic Properties Of Lsmo/Sto Thin Films: Magnetocaloric, Spin Dynamics And Magnetic Viscosity Investigations, Navid Mottaghi

Graduate Theses, Dissertations, and Problem Reports

While other films are discussed, this dissertation will focus on detailed studies of the dc and ac bulk magnetometry in a characteristic 7.6 nm thin film of La_0.7Sr_0.3MnO₃ grown on SrTiO₃ (001). The dc bulk magnetometry measurements show that the sample is magnetically inhomogeneous. Temperature variation of magnetization (M vs. T) was measured in zero-field-cooled and field-cooled protocols to determine the blocking temperature T_B in different applied magnetic fields. The field variation of T_B is interpreted as the presence of embedded spin clusters of 1.4 nm. Moreover, the M vs. …

The Green Bank Observatory And The Space Race - Introduction, Katelyn Flanagan

West Virginia Connection

For this portion of the materials, I included two “Piktographs” for students to use as a resource for their research for the final assignment. The first is one on the contributions specifically from West Virginia to the space race. It includes specific people from West Virginia and their contributions to this portion of our nation’s history. This way students are able to make home connections to West Virginia. The second Piktograph is one specifically on The Green Bank Observatory located in Green Bank, WV. It is home to the first radio telescope, as well as being the first national astronomy …

The Space Race Piktograph, Katelyn Flanagan

West Virginia Connection

For this portion of the materials, I included two “Piktographs” for students to use as a resource for their research for the final assignment. The first is one on the contributions specifically from West Virginia to the space race. It includes specific people from West Virginia and their contributions to this portion of our nation’s history. This way students are able to make home connections to West Virginia. The second Piktograph is one specifically on The Green Bank Observatory located in Green Bank, WV. It is home to the first radio telescope, as well as being the first national astronomy …

The Green Bank Observatory Piktograph, Katelyn Flanagan

West Virginia Connection

For this portion of the materials, I included two “Piktographs” for students to use as a resource for their research for the final assignment. The first is one on the contributions specifically from West Virginia to the space race. It includes specific people from West Virginia and their contributions to this portion of our nation’s history. This way students are able to make home connections to West Virginia. The second Piktograph is one specifically on The Green Bank Observatory located in Green Bank, WV. It is home to the first radio telescope, as well as being the first national astronomy …