{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/21062"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/21062","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Tapping space and spacing taps: Topics in radar-astronomy imaging and sparse filter design","abstract":"This dissertation addresses topics in the areas of synthetic aperture radar (SAR) and finite impulse-response (FIR) digital filter design.","abstract_html":"This dissertation addresses topics in the areas of synthetic aperture radar (SAR) and finite impulse-response (FIR) digital filter design.","abstract_has_math":false,"creators":["Webb, Jennifer Lois Harmon"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Electrical Engineering","degree_department":null,"school":null,"contributors":["Munson, David C., Jr."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T12:57:14Z","date_published":"2011-05-07T12:57:14Z","updated_at":"2026-07-22T22:25:17Z","subjects":["Engineering, Electronics and Electrical"],"languages":["eng"],"rights":["Copyright 1995 Webb, Jennifer Lois Harmon"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9624533","(UMI)AAI9624533"],"render_values":[{"text":"AAI9624533","href":null,"code":true},{"text":"(UMI)AAI9624533","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/21062","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Munson, David C., Jr."]},{"key":"dc:creator","label":"Author","values":["Webb, Jennifer Lois Harmon"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T12:57:14Z","10000-01-01","1995"]},{"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":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1995 Webb, Jennifer Lois Harmon"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9624533","(UMI)AAI9624533","http://hdl.handle.net/2142/21062"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This dissertation addresses topics in the areas of synthetic aperture radar (SAR) and finite impulse-response (FIR) digital filter design.","This investigation of SAR was based on a tomographic viewpoint. An existing form of spotlight-mode SAR processing was applied to a radar-astronomy application, forming images of the moon's surface from radar-astronomy data collected at Arecibo Observatory. In doing so, high-quality images were obtained while significantly reducing the number of computations required. It was found that a slight degradation was caused by arcing in the radar path.","This discovery led to a detailed investigation of the impact of radar maneuvers on SAR image formation. A method for improving image quality was developed, based on a piecewise-linear model for the radar path. To determine the number of segments required, and the appropriateness of this model, constraints were derived for the length of the linear path segments. The method was demonstrated for 1-D images with point scatterers and extended targets.","Another study, motivated by the problem of imaging asteroids, involved the formation of 3-D SAR images using limited data. When the surface reflectivity is known to be concentrated on the surface, it is possible to cast this problem into the framework of an angle-of-arrival or spectral-estimation problem. Thus, techniques such as ESPRIT and RELAX can be applied to form the sparse 3-D image. The image-formation method was demonstrated through simulation.","Other work deals with FIR digital filter design. These studies involved designing filters for which some of the tap weights are constrained to be zero. First, cases were considered where the locations of the zeroed tap weights are known; linear programming was used to optimize the remaining tap weights. If the goal is to reduce the number of multiplications, the locations of the zeroed tap weights must be determined first. For a class of filters, these locations were determined and a sparse direct-form filter was designed using linear programming. A second new design method was developed for filters implemented with cascades of sparse and nonsparse sections.","Made available in DSpace on 2011-05-07T12:57:14Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9624533.pdf: 5405113 bytes, checksum: 5913de02784a1caff9a6c4e629cf621d (MD5) Previous issue date: 1995","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:48:13Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:21:49-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Tapping space and spacing taps: Topics in radar-astronomy imaging and sparse filter design"]}]}],"canonical_facts":{"dc:contributor":["Munson, David C., Jr."],"dc:creator":["Webb, Jennifer Lois Harmon"],"dc:date":["2011-05-07T12:57:14Z","10000-01-01","1995"],"dc:description":["This dissertation addresses topics in the areas of synthetic aperture radar (SAR) and finite impulse-response (FIR) digital filter design.","This investigation of SAR was based on a tomographic viewpoint. An existing form of spotlight-mode SAR processing was applied to a radar-astronomy application, forming images of the moon's surface from radar-astronomy data collected at Arecibo Observatory. In doing so, high-quality images were obtained while significantly reducing the number of computations required. It was found that a slight degradation was caused by arcing in the radar path.","This discovery led to a detailed investigation of the impact of radar maneuvers on SAR image formation. A method for improving image quality was developed, based on a piecewise-linear model for the radar path. To determine the number of segments required, and the appropriateness of this model, constraints were derived for the length of the linear path segments. The method was demonstrated for 1-D images with point scatterers and extended targets.","Another study, motivated by the problem of imaging asteroids, involved the formation of 3-D SAR images using limited data. When the surface reflectivity is known to be concentrated on the surface, it is possible to cast this problem into the framework of an angle-of-arrival or spectral-estimation problem. Thus, techniques such as ESPRIT and RELAX can be applied to form the sparse 3-D image. The image-formation method was demonstrated through simulation.","Other work deals with FIR digital filter design. These studies involved designing filters for which some of the tap weights are constrained to be zero. First, cases were considered where the locations of the zeroed tap weights are known; linear programming was used to optimize the remaining tap weights. If the goal is to reduce the number of multiplications, the locations of the zeroed tap weights must be determined first. For a class of filters, these locations were determined and a sparse direct-form filter was designed using linear programming. A second new design method was developed for filters implemented with cascades of sparse and nonsparse sections.","Made available in DSpace on 2011-05-07T12:57:14Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9624533.pdf: 5405113 bytes, checksum: 5913de02784a1caff9a6c4e629cf621d (MD5) Previous issue date: 1995","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:48:13Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:21:49-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9624533","(UMI)AAI9624533","http://hdl.handle.net/2142/21062"],"dc:language":["eng"],"dc:rights":["Copyright 1995 Webb, Jennifer Lois Harmon"],"dc:subject":["Engineering, Electronics and Electrical"],"dc:title":["Tapping space and spacing taps: Topics in radar-astronomy imaging and sparse filter design"],"dc:type":["text"],"thesis:degree_discipline":["Electrical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:17Z"}