{"id":{"repo_id":"gatech","oai_identifier":"oai:repository.gatech.edu:1853/64560"},"canonical_url":"https://search.dev.ndltd.org/etd/gatech/oai:repository.gatech.edu:1853/64560","repository":{"repo_id":"gatech","name":"Georgia Tech","base_url":"https://repository.gatech.edu/server/oai/request"},"display":{"title":"A GEOMETRIC VARIATIONAL APPROACH TO SHAPE INVERSION FOR RADAR","abstract":"In this thesis, we develop a novel method for dense shape reconstruction of scenes using radar. For a given scene and antennas taking measurements from the scene, our method iteratively estimates the scene shape using the measurements. To this end, we use a deformable shape evolution approach which seeks to match the received signal to a computed forward model based on the evolving shape. Adopting such an approach comes with important advantages such as the ability to naturally embed the shape priors into the estimation and being able to model self-occlusions which cannot be easily incorporated into classical radar imaging techniques. Iterations start with an initial shape model which is gradually deformed until its image under the forward model gets sufficiently close to the actual measurements. Since we use a gradient-based scheme to minimize our error and radar signals are highly oscillatory, a special attention is required to prevent these oscillations to manifest in the cost functional as local minima. For this purpose, we develop a novel technique by which we can extract the geometric information embedded in the radar signals that is used to formulate a well behaving cost functional. We test our approach with synthetic simulations performed in 2D which shows the promise of our approach on some challenging scenarios.","abstract_html":"In this thesis, we develop a novel method for dense shape reconstruction of scenes using radar. For a given scene and antennas taking measurements from the scene, our method iteratively estimates the scene shape using the measurements. To this end, we use a deformable shape evolution approach which seeks to match the received signal to a computed forward model based on the evolving shape. Adopting such an approach comes with important advantages such as the ability to naturally embed the shape priors into the estimation and being able to model self-occlusions which cannot be easily incorporated into classical radar imaging techniques. Iterations start with an initial shape model which is gradually deformed until its image under the forward model gets sufficiently close to the actual measurements. Since we use a gradient-based scheme to minimize our error and radar signals are highly oscillatory, a special attention is required to prevent these oscillations to manifest in the cost functional as local minima. For this purpose, we develop a novel technique by which we can extract the geometric information embedded in the radar signals that is used to formulate a well behaving cost functional. We test our approach with synthetic simulations performed in 2D which shows the promise of our approach on some challenging scenarios.","abstract_has_math":false,"creators":["Yildirim, Alper"],"institution":"Georgia Institute of Technology","degree_name":null,"degree_level":"Doctoral","degree_discipline":null,"degree_department":"Electrical and Computer Engineering","school":null,"contributors":[],"advisors":["Yezzi, Anthony"],"committee_chairs":[],"committee_members":["Barnes, Christopher F","Vela, Patricio A","Orlando, Thomas","Lanterman, Aeron D"],"year":2020,"date_issued":"2020-01-21","date_published":"2020-01-21","updated_at":"2026-07-27T19:48:57Z","subjects":["shape inversion, radar, shape, level sets, active contours, variational optimization,"],"languages":["en_US"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1853/64560","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Yezzi, Anthony"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Barnes, Christopher F","Vela, Patricio A","Orlando, Thomas","Lanterman, Aeron D"]},{"key":"dc:contributor.department","label":"Department","values":["Electrical and Computer Engineering"]},{"key":"dc:creator","label":"Author","values":["Yildirim, Alper"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2021-06-10T13:49:09Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2021-06-10T13:49:09Z"]},{"key":"dc:date.issued","label":"Date","values":["2020-01-21"]},{"key":"dc:publisher","label":"Institution","values":["Georgia Institute of Technology"]},{"key":"dc:type","label":"Dc Type","values":["Text"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Doctoral"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["shape inversion, radar, shape, level sets, active contours, variational optimization,"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1853/64560"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["In this thesis, we develop a novel method for dense shape reconstruction of scenes using radar. For a given scene and antennas taking measurements from the scene, our method iteratively estimates the scene shape using the measurements. To this end, we use a deformable shape evolution approach which seeks to match the received signal to a computed forward model based on the evolving shape. Adopting such an approach comes with important advantages such as the ability to naturally embed the shape priors into the estimation and being able to model self-occlusions which cannot be easily incorporated into classical radar imaging techniques. Iterations start with an initial shape model which is gradually deformed until its image under the forward model gets sufficiently close to the actual measurements. Since we use a gradient-based scheme to minimize our error and radar signals are highly oscillatory, a special attention is required to prevent these oscillations to manifest in the cost functional as local minima. For this purpose, we develop a novel technique by which we can extract the geometric information embedded in the radar signals that is used to formulate a well behaving cost functional. We test our approach with synthetic simulations performed in 2D which shows the promise of our approach on some challenging scenarios."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph.D."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["A GEOMETRIC VARIATIONAL APPROACH TO SHAPE INVERSION FOR RADAR"]}]}],"canonical_facts":{"dc:contributor.advisor":["Yezzi, Anthony"],"dc:contributor.committeemember":["Barnes, Christopher F","Vela, Patricio A","Orlando, Thomas","Lanterman, Aeron D"],"dc:contributor.department":["Electrical and Computer Engineering"],"dc:creator":["Yildirim, Alper"],"dc:date.accessioned":["2021-06-10T13:49:09Z"],"dc:date.available":["2021-06-10T13:49:09Z"],"dc:date.issued":["2020-01-21"],"dc:description.abstract":["In this thesis, we develop a novel method for dense shape reconstruction of scenes using radar. For a given scene and antennas taking measurements from the scene, our method iteratively estimates the scene shape using the measurements. To this end, we use a deformable shape evolution approach which seeks to match the received signal to a computed forward model based on the evolving shape. Adopting such an approach comes with important advantages such as the ability to naturally embed the shape priors into the estimation and being able to model self-occlusions which cannot be easily incorporated into classical radar imaging techniques. Iterations start with an initial shape model which is gradually deformed until its image under the forward model gets sufficiently close to the actual measurements. Since we use a gradient-based scheme to minimize our error and radar signals are highly oscillatory, a special attention is required to prevent these oscillations to manifest in the cost functional as local minima. 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