{"593790":{"#nid":"593790","#data":{"type":"event","title":"Ph.D. Proposal Oral Exam - Jackson McCormick","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ETitle:\u0026nbsp; \u003C\/strong\u003E\u003Cem\u003ED-region Ionospheric Imaging using Lightning Generated Sferics, Forward Modeling, and Tomography\u003C\/em\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECommittee:\u0026nbsp; \u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Cohen, Advisor\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Romberg, Chair\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Simon\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Bibby\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAbstract: \u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe objective of the proposed research is to produce and evaluate the capabilities of producing a 2D image of the D-region ionospheric parameterization. The D-region of the ionosphere (60-90 km altitude) is highly variable on timescales from fractions of a second to many hours, and on spatial scales up to many hundreds of km. VLF and LF (3-30 kHz, 30-300 kHz) radio waves are guided to global distances by reflections from the ground and the D-region. Therefore, information about the current state of the ionosphere is encoded in received VLF\/LF signals. VLF transmitters, for example, have been used in the past for ionospheric remote sensing, with ionospheric disturbances manifesting as perturbations in amplitude and\/or phase. The return stroke of lightning is also an impulsive VLF radiator, but unlike VLF transmitters, lightning flashes are spread broadly in space allowing for much greater spatial coverage of the D-region compared to VLF transmitter-based remote sensing in addition to the broadband spectral advantage over the narrowband transmitters. The challenge is that individual lightning-generated waveforms, or \u0026lsquo;sferics\u0026rsquo;, vary due to the lightning current parameters and uncertainty in the time\/location information, in addition to D-region ionospheric variability. In part, proposal describes a technique to mitigate this variability to produce stable, high-SNR sferic measurements. Using a model, the received sferics can be used to infer an ionospheric profile that is interpreted as an average along the path from lighting stroke to receiver. Through a tomographic technique, these sparse and sporadic path average inferences can be combined to calculate a 2D image of the D-region electron density profile.\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"D-region Ionospheric Imaging using Lightning Generated Sferics, Forward Modeling, and Tomography"}],"uid":"28475","created_gmt":"2017-07-27 19:43:40","changed_gmt":"2017-07-27 19:43:40","author":"Daniela Staiculescu","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2017-08-09T16:00:00-04:00","event_time_end":"2017-08-09T18:00:00-04:00","event_time_end_last":"2017-08-09T18:00:00-04:00","gmt_time_start":"2017-08-09 20:00:00","gmt_time_end":"2017-08-09 22:00:00","gmt_time_end_last":"2017-08-09 22:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"434371","name":"ECE Ph.D. Proposal Oral Exams"}],"categories":[],"keywords":[{"id":"102851","name":"Phd proposal"},{"id":"1808","name":"graduate students"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}