{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/69268"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/69268","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"A Consideration of Signal Processing for Spotlight Synthetic Aperture Radar (Ambiguity Functions)","abstract":"An analysis of spotlight mode synthetic aperture radar (SAR) imaging was carried out using a model based solely on the recognizable similarity it shares with tomographic reconstruction. Doppler effects were relegated to a pre-processing step. Results of this investigation included a determination of the importance of: (1) rectangular versus polar formatting of data for imaging, (2) limited time-bandwidth of chirp signals if stretch processing is employed, (3) residual Doppler effects, and (4) spherical wavefront curvature. Furthermore, the applicability of the convolution back-projection algorithm for imaging spotlight SAR data was established.","abstract_html":"An analysis of spotlight mode synthetic aperture radar (SAR) imaging was carried out using a model based solely on the recognizable similarity it shares with tomographic reconstruction. Doppler effects were relegated to a pre-processing step. Results of this investigation included a determination of the importance of: (1) rectangular versus polar formatting of data for imaging, (2) limited time-bandwidth of chirp signals if stretch processing is employed, (3) residual Doppler effects, and (4) spherical wavefront curvature. Furthermore, the applicability of the convolution back-projection algorithm for imaging spotlight SAR data was established.","abstract_has_math":false,"creators":["O'brien, James Dennis"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Electrical Engineering","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-12-15T19:04:38Z","date_published":"2014-12-15T19:04:38Z","updated_at":"2026-07-22T22:26:00Z","subjects":["Engineering, Electronics and Electrical"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8409821"],"render_values":[{"text":"(UMI)AAI8409821","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/69268","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["O'brien, James Dennis"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-15T19:04:38Z","10000-01-01","1984"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering, Electronics and Electrical"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/69268","(UMI)AAI8409821"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["An analysis of spotlight mode synthetic aperture radar (SAR) imaging was carried out using a model based solely on the recognizable similarity it shares with tomographic reconstruction. Doppler effects were relegated to a pre-processing step. Results of this investigation included a determination of the importance of: (1) rectangular versus polar formatting of data for imaging, (2) limited time-bandwidth of chirp signals if stretch processing is employed, (3) residual Doppler effects, and (4) spherical wavefront curvature. Furthermore, the applicability of the convolution back-projection algorithm for imaging spotlight SAR data was established.","A second part of the thesis was concerned with the design of two-dimensional tapers, or windows, for Fourier transformation of data collected over arbitrarily shaped apertures. If the intent is to minimize sidelobe energy, the generalized prolate spheroidal eigen-equation of Slepian can be solved in a simple iterative manner using a digital computer to obtain the taper. Computer solutions for several aperture shapes of interest were presented.","A novel analysis of interpolation artifacts was given to explain the appearance of defocused, spurious targets which appear from digital processing of data which has been interpolated from a partial polar raster onto a rectangular raster. The polar raster arises, in the context of the SAR application, from the manner of data collection, whereas digital processing is facilitated using data sampled on a rectangular raster.","Finally, the bi-static SAR problem was examined in its relation to other forms of near-field imaging and direct parallels were drawn. With less restrictive geometries, the optimal processor was again seen to be the spatially varying matched filter.","Made available in DSpace on 2014-12-15T19:04:38Z (GMT). No. of bitstreams: 1 8409821.pdf: 3524036 bytes, checksum: e0fc88acd5c72d83a96ceba324b70f45 (MD5) Previous issue date: 1984","Embargo set by: Seth Robbins for item 69434 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","119 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1984."]},{"key":"dc:title","label":"Title","values":["A Consideration of Signal Processing for Spotlight Synthetic Aperture Radar (Ambiguity Functions)"]}]}],"canonical_facts":{"dc:creator":["O'brien, James Dennis"],"dc:date":["2014-12-15T19:04:38Z","10000-01-01","1984"],"dc:description":["An analysis of spotlight mode synthetic aperture radar (SAR) imaging was carried out using a model based solely on the recognizable similarity it shares with tomographic reconstruction. Doppler effects were relegated to a pre-processing step. Results of this investigation included a determination of the importance of: (1) rectangular versus polar formatting of data for imaging, (2) limited time-bandwidth of chirp signals if stretch processing is employed, (3) residual Doppler effects, and (4) spherical wavefront curvature. Furthermore, the applicability of the convolution back-projection algorithm for imaging spotlight SAR data was established.","A second part of the thesis was concerned with the design of two-dimensional tapers, or windows, for Fourier transformation of data collected over arbitrarily shaped apertures. If the intent is to minimize sidelobe energy, the generalized prolate spheroidal eigen-equation of Slepian can be solved in a simple iterative manner using a digital computer to obtain the taper. Computer solutions for several aperture shapes of interest were presented.","A novel analysis of interpolation artifacts was given to explain the appearance of defocused, spurious targets which appear from digital processing of data which has been interpolated from a partial polar raster onto a rectangular raster. The polar raster arises, in the context of the SAR application, from the manner of data collection, whereas digital processing is facilitated using data sampled on a rectangular raster.","Finally, the bi-static SAR problem was examined in its relation to other forms of near-field imaging and direct parallels were drawn. With less restrictive geometries, the optimal processor was again seen to be the spatially varying matched filter.","Made available in DSpace on 2014-12-15T19:04:38Z (GMT). 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