2026-09-22T13:22:40Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/46790 2023-07-11 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Kudeki, Erhan Aggarwal, Deepanshu 2014-01-16T18:02:36Z 2014-01-16T18:02:36Z 2013-12 2014-01-16T18:02:36Z 2013-12 This thesis describes a project on the modeling of spectral characteristics of electron density irregularities of the topside equatorial ionosphere probed by the Jicamarca Incoherent Scatter Radar (ISR) located near Lima, Peru. The topside equatorial ionosphere is a multi-ion plasma and the spectrum of its electron density irregularities can be modeled by extending the single-ion spectral model developed by Kudeki and Milla (2011) for a collisional equatorial F-region ionosphere. This single-ion model of Kudeki and Milla captures the essential physics of the equatorial F-region ionosphere where random displacements of the dominant oxygen ions are characterized as a Brownian-motion process, while electron displacements are non-Brownian and described in terms of a numerical library (constructed using a Monte-Carlo approach) of single-electron ACFs (autocorrelation functions) parametrized by five state parameters of the F-region consisting of ionospheric electron density, geomagnetic flux density, electron and ion temperatures, and the deviation angle of the radar boresight direction from the plane perpendicular to the geomagnetic field, the so-called magnetic aspect angle. While the extension of the model to the multi-ion case is straightforward, the discrete nature of the numerical electron ACF library defined over a grid of input parameters precludes the evaluation of the extended model with arbitrary and continuously varying input parameters. To overcome this difficulty a machine learning (ML) based interpolation procedure is developed. The thesis describes the ML algorithm, the associated training and testing steps, and finally presents a suite of examples of multi-ion IS spectra obtained with the extended model. Item withdrawn by Laura Spradlin (lspradl2@illinois.edu) on 2013-12-10T15:32:49Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Aggarwal_Deepanshu.pdf: 952081 bytes, checksum: 73f27fcbc05140a2bc4b138e0a4670e3 (MD5) Made available in DSpace on 2014-01-16T18:02:36Z (GMT). No. of bitstreams: 2 Deepanshu_Aggarwal.pdf: 952081 bytes, checksum: 73f27fcbc05140a2bc4b138e0a4670e3 (MD5) license.txt: 4068 bytes, checksum: b4815fd3654aabed87f4dfcf5af4dfc7 (MD5) http://hdl.handle.net/2142/46790 en Copyright 2013 Deepanshu Aggarwal Jicamarca Radar spectra k-Nearest Neighbors (KNN) Machine Learning Ionosphere Collision Frequency Machine Learning Electron ion collision Incoherent scatter modeling of Jicamarca radar spectra text Electrical and Computer Engineering 1933 Electrical & Computer Engineering 1200 University of Illinois at Urbana-Champaign Thesis M.S. MS:Electr & Computer Eng-UIUC 10KS1200MS