{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/34715"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/34715","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"A Pilot Survey for Astronomical Low Frequency Radio Transients","abstract":"Dispersed low-frequency radio astronomical pulses may result from exploding primordial black holes, gamma ray bursts, supernovae, or mergers of exotic objects, but have not yet been detected. Detection would be of great scientific significance because such events must involve extreme physics. The transient nature of these events makes detection unlikely with traditional instruments due to lack of sensitivity to single pulses and narrow field of view. For this thesis, a low-frequency wide-bandwidth astronomical search instrument has been developed as an alternative approach. This instrument consists of a single dipole which yields all-sky field of view, albeit at reduced sensitivity. The spectrum from 37 - 55 MHz is coherently digitized at 200 million samples per second, recorded, and analyzed off-line for the presence of dispersed pulses. A preliminary survey has been made at a remote site in western North Carolina. In a 20 minute observation, 9 detections greater than 6.5σ occurred, corresponding to pulses of ≤ 20 ms duration and dispersion measures (DMs) ranging from 15 to 70 pc cm⁻³. In addition, groups of pulses were detected ( 5) at DMs of 43.1, 52.1, and 52.2 pc cm⁻³. The possibility of association with known pulsars is considered; however, it is also possible these are due simply to radio frequency interference. Improvements to this instrument and survey technique are suggested.","abstract_html":"Dispersed low-frequency radio astronomical pulses may result from exploding primordial black holes, gamma ray bursts, supernovae, or mergers of exotic objects, but have not yet been detected. Detection would be of great scientific significance because such events must involve extreme physics. The transient nature of these events makes detection unlikely with traditional instruments due to lack of sensitivity to single pulses and narrow field of view. For this thesis, a low-frequency wide-bandwidth astronomical search instrument has been developed as an alternative approach. This instrument consists of a single dipole which yields all-sky field of view, albeit at reduced sensitivity. The spectrum from 37 - 55 MHz is coherently digitized at 200 million samples per second, recorded, and analyzed off-line for the presence of dispersed pulses. A preliminary survey has been made at a remote site in western North Carolina. In a 20 minute observation, 9 detections greater than 6.5σ occurred, corresponding to pulses of ≤ 20 ms duration and dispersion measures (DMs) ranging from 15 to 70 pc cm⁻³. In addition, groups of pulses were detected ( 5) at DMs of 43.1, 52.1, and 52.2 pc cm⁻³. The possibility of association with known pulsars is considered; however, it is also possible these are due simply to radio frequency interference. Improvements to this instrument and survey technique are suggested.","abstract_has_math":false,"creators":["Wilson, Derek Edwin"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Electrical and Computer Engineering","degree_department":"Electrical and Computer Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Ellingson, Steven W."],"committee_members":["Reed, Jeffrey H.","Brown, Gary S."],"year":2005,"date_issued":"2005-08-23","date_published":"2005-08-23","updated_at":"2026-07-22T22:18:58Z","subjects":["digital signal processing","radio astronomy","astronomical transients"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-08232005-212614"],"render_values":[{"text":"etd-08232005-212614","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/34715","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Ellingson, Steven W."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Reed, Jeffrey H.","Brown, Gary S."]},{"key":"dc:contributor.department","label":"Department","values":["Electrical and Computer Engineering"]},{"key":"dc:creator","label":"Author","values":["Wilson, Derek Edwin"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:44:03Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:44:03Z","2005-12-06"]},{"key":"dc:date.issued","label":"Date","values":["2005-08-23"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical and Computer Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["digital signal processing","radio astronomy","astronomical transients"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-08232005-212614"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/34715"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Dispersed low-frequency radio astronomical pulses may result from exploding primordial black holes, gamma ray bursts, supernovae, or mergers of exotic objects, but have not yet been detected. Detection would be of great scientific significance because such events must involve extreme physics. The transient nature of these events makes detection unlikely with traditional instruments due to lack of sensitivity to single pulses and narrow field of view. For this thesis, a low-frequency wide-bandwidth astronomical search instrument has been developed as an alternative approach. This instrument consists of a single dipole which yields all-sky field of view, albeit at reduced sensitivity. The spectrum from 37 - 55 MHz is coherently digitized at 200 million samples per second, recorded, and analyzed off-line for the presence of dispersed pulses. A preliminary survey has been made at a remote site in western North Carolina. In a 20 minute observation, 9 detections greater than 6.5σ occurred, corresponding to pulses of ≤ 20 ms duration and dispersion measures (DMs) ranging from 15 to 70 pc cm⁻³. In addition, groups of pulses were detected ( 5) at DMs of 43.1, 52.1, and 52.2 pc cm⁻³. The possibility of association with known pulsars is considered; however, it is also possible these are due simply to radio frequency interference. Improvements to this instrument and survey technique are suggested."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["A Pilot Survey for Astronomical Low Frequency Radio Transients"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Ellingson, Steven W."],"dc:contributor.committeemember":["Reed, Jeffrey H.","Brown, Gary S."],"dc:contributor.department":["Electrical and Computer Engineering"],"dc:creator":["Wilson, Derek Edwin"],"dc:date.accessioned":["2014-03-14T20:44:03Z"],"dc:date.available":["2014-03-14T20:44:03Z","2005-12-06"],"dc:date.issued":["2005-08-23"],"dc:description.abstract":["Dispersed low-frequency radio astronomical pulses may result from exploding primordial black holes, gamma ray bursts, supernovae, or mergers of exotic objects, but have not yet been detected. Detection would be of great scientific significance because such events must involve extreme physics. The transient nature of these events makes detection unlikely with traditional instruments due to lack of sensitivity to single pulses and narrow field of view. For this thesis, a low-frequency wide-bandwidth astronomical search instrument has been developed as an alternative approach. This instrument consists of a single dipole which yields all-sky field of view, albeit at reduced sensitivity. The spectrum from 37 - 55 MHz is coherently digitized at 200 million samples per second, recorded, and analyzed off-line for the presence of dispersed pulses. A preliminary survey has been made at a remote site in western North Carolina. In a 20 minute observation, 9 detections greater than 6.5σ occurred, corresponding to pulses of ≤ 20 ms duration and dispersion measures (DMs) ranging from 15 to 70 pc cm⁻³. In addition, groups of pulses were detected ( 5) at DMs of 43.1, 52.1, and 52.2 pc cm⁻³. The possibility of association with known pulsars is considered; however, it is also possible these are due simply to radio frequency interference. Improvements to this instrument and survey technique are suggested."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-08232005-212614"],"dc:identifier.uri":["http://hdl.handle.net/10919/34715"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["digital signal processing","radio astronomy","astronomical transients"],"dc:title":["A Pilot Survey for Astronomical Low Frequency Radio Transients"],"dc:type":["Thesis"],"thesis:degree_discipline":["Electrical and Computer Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:18:58Z"}