{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/97515"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/97515","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Attack resilient GPS based timing for phasor measurement units using multi-receiver direct time estimation","abstract":"Modern power distribution systems are incorporating Phasor Measurement Units (PMUs) to measure the instantaneous voltage and current phasors at different nodes in the power grid. These PMUs depend on Global Positioning Systems (GPS) for precise time and synchronization. However, GPS civil signals are vulnerable to external attacks because of its low power and unencrypted signal structure. Therefore, there is a need for the development of attack resilient GPS time transfer techniques to ensure power grid stability. To counteract these adverse effects, we propose an innovative Multi-Receiver Direct Time Estimation (MR-DTE) algorithm by utilizing the measurements from multiple GPS receivers driven by a common clock. The raw GPS signals from each receiver are processed using a robust signal processing technique known as Direct Time Estimation (DTE). DTE directly correlates the received GPS signal with the corresponding signal replica for each of the pre-generated set of clock states. The optimal set of clock candidates is then determined by maximum likelihood estimation. We further leverage the known geographical diversity of multiple receivers and apply Kalman Filter to obtain robust GPS timing. We evaluate the improved robustness of our MR-DTE algorithm against external timing attacks based on GPS field experiments. In addition, we design a verification and validation power grid testbed using Real-Time Digital Simulator (RTDS) to demonstrate the impact of jamming, meaconing (i.e., record-andreplay attack) and satellite data-level anomalies on PMUs. Later, we utilize our power grid testbed to validate the attack-resilience of our proposed MR-DTE algorithm in comparison to the existing techniques such as traditional scalar tracking and Position-Information-Aided Vector Tracking.","abstract_html":"Modern power distribution systems are incorporating Phasor Measurement Units (PMUs) to measure the instantaneous voltage and current phasors at different nodes in the power grid. These PMUs depend on Global Positioning Systems (GPS) for precise time and synchronization. However, GPS civil signals are vulnerable to external attacks because of its low power and unencrypted signal structure. Therefore, there is a need for the development of attack resilient GPS time transfer techniques to ensure power grid stability. To counteract these adverse effects, we propose an innovative Multi-Receiver Direct Time Estimation (MR-DTE) algorithm by utilizing the measurements from multiple GPS receivers driven by a common clock. The raw GPS signals from each receiver are processed using a robust signal processing technique known as Direct Time Estimation (DTE). DTE directly correlates the received GPS signal with the corresponding signal replica for each of the pre-generated set of clock states. The optimal set of clock candidates is then determined by maximum likelihood estimation. We further leverage the known geographical diversity of multiple receivers and apply Kalman Filter to obtain robust GPS timing. We evaluate the improved robustness of our MR-DTE algorithm against external timing attacks based on GPS field experiments. In addition, we design a verification and validation power grid testbed using Real-Time Digital Simulator (RTDS) to demonstrate the impact of jamming, meaconing (i.e., record-andreplay attack) and satellite data-level anomalies on PMUs. Later, we utilize our power grid testbed to validate the attack-resilience of our proposed MR-DTE algorithm in comparison to the existing techniques such as traditional scalar tracking and Position-Information-Aided Vector Tracking.","abstract_has_math":false,"creators":["Bhamidipati, Sri Ramya"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Aerospace Engineering","degree_department":null,"school":null,"contributors":["Gao, Grace Xingxin"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-08-10T19:16:23Z","date_published":"2017-08-10T19:16:23Z","updated_at":"2026-07-22T22:24:34Z","subjects":["Global positioning systems","Phasor measurement units","Timing attacks"],"languages":["en"],"rights":["Copyright 2017 Sriramya Bhamidipati"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/97515","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Gao, Grace Xingxin"]},{"key":"dc:creator","label":"Author","values":["Bhamidipati, Sri Ramya"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2017-08-10T19:16:23Z","2017-04-28","2017-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Aerospace Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"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":["Global positioning systems","Phasor measurement units","Timing attacks"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2017 Sriramya Bhamidipati"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/97515"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Modern power distribution systems are incorporating Phasor Measurement Units (PMUs) to measure the instantaneous voltage and current phasors at different nodes in the power grid. These PMUs depend on Global Positioning Systems (GPS) for precise time and synchronization. However, GPS civil signals are vulnerable to external attacks because of its low power and unencrypted signal structure. Therefore, there is a need for the development of attack resilient GPS time transfer techniques to ensure power grid stability. To counteract these adverse effects, we propose an innovative Multi-Receiver Direct Time Estimation (MR-DTE) algorithm by utilizing the measurements from multiple GPS receivers driven by a common clock. The raw GPS signals from each receiver are processed using a robust signal processing technique known as Direct Time Estimation (DTE). DTE directly correlates the received GPS signal with the corresponding signal replica for each of the pre-generated set of clock states. The optimal set of clock candidates is then determined by maximum likelihood estimation. We further leverage the known geographical diversity of multiple receivers and apply Kalman Filter to obtain robust GPS timing. We evaluate the improved robustness of our MR-DTE algorithm against external timing attacks based on GPS field experiments. In addition, we design a verification and validation power grid testbed using Real-Time Digital Simulator (RTDS) to demonstrate the impact of jamming, meaconing (i.e., record-andreplay attack) and satellite data-level anomalies on PMUs. Later, we utilize our power grid testbed to validate the attack-resilience of our proposed MR-DTE algorithm in comparison to the existing techniques such as traditional scalar tracking and Position-Information-Aided Vector Tracking.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-08-10 without embargo terms","The student, Sri Ramya Bhamidipati, accepted the attached license on 2017-04-28 at 11:12.","The student, Sri Ramya Bhamidipati, submitted this Thesis for approval on 2017-04-28 at 11:25.","This Thesis was approved for publication on 2017-04-28 at 12:14.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11134 on 2017-08-10 at 13:47:03","Made available in DSpace on 2017-08-10T19:16:23Z (GMT). No. of bitstreams: 2 BHAMIDIPATI-THESIS-2017.pdf: 6661201 bytes, checksum: abaaf2c6892ec241db4bb81e0c093eb3 (MD5) LICENSE.txt: 4218 bytes, checksum: 2916ed289fd7c8d74fd9c5ef19d6e79e (MD5) Previous issue date: 2017-04-28"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Attack resilient GPS based timing for phasor measurement units using multi-receiver direct time estimation"]}]}],"canonical_facts":{"dc:contributor":["Gao, Grace Xingxin"],"dc:creator":["Bhamidipati, Sri Ramya"],"dc:date":["2017-08-10T19:16:23Z","2017-04-28","2017-05"],"dc:description":["Modern power distribution systems are incorporating Phasor Measurement Units (PMUs) to measure the instantaneous voltage and current phasors at different nodes in the power grid. These PMUs depend on Global Positioning Systems (GPS) for precise time and synchronization. However, GPS civil signals are vulnerable to external attacks because of its low power and unencrypted signal structure. Therefore, there is a need for the development of attack resilient GPS time transfer techniques to ensure power grid stability. To counteract these adverse effects, we propose an innovative Multi-Receiver Direct Time Estimation (MR-DTE) algorithm by utilizing the measurements from multiple GPS receivers driven by a common clock. The raw GPS signals from each receiver are processed using a robust signal processing technique known as Direct Time Estimation (DTE). DTE directly correlates the received GPS signal with the corresponding signal replica for each of the pre-generated set of clock states. The optimal set of clock candidates is then determined by maximum likelihood estimation. We further leverage the known geographical diversity of multiple receivers and apply Kalman Filter to obtain robust GPS timing. We evaluate the improved robustness of our MR-DTE algorithm against external timing attacks based on GPS field experiments. In addition, we design a verification and validation power grid testbed using Real-Time Digital Simulator (RTDS) to demonstrate the impact of jamming, meaconing (i.e., record-andreplay attack) and satellite data-level anomalies on PMUs. Later, we utilize our power grid testbed to validate the attack-resilience of our proposed MR-DTE algorithm in comparison to the existing techniques such as traditional scalar tracking and Position-Information-Aided Vector Tracking.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-08-10 without embargo terms","The student, Sri Ramya Bhamidipati, accepted the attached license on 2017-04-28 at 11:12.","The student, Sri Ramya Bhamidipati, submitted this Thesis for approval on 2017-04-28 at 11:25.","This Thesis was approved for publication on 2017-04-28 at 12:14.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11134 on 2017-08-10 at 13:47:03","Made available in DSpace on 2017-08-10T19:16:23Z (GMT). No. of bitstreams: 2 BHAMIDIPATI-THESIS-2017.pdf: 6661201 bytes, checksum: abaaf2c6892ec241db4bb81e0c093eb3 (MD5) LICENSE.txt: 4218 bytes, checksum: 2916ed289fd7c8d74fd9c5ef19d6e79e (MD5) Previous issue date: 2017-04-28"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/97515"],"dc:language":["en"],"dc:rights":["Copyright 2017 Sriramya Bhamidipati"],"dc:subject":["Global positioning systems","Phasor measurement units","Timing attacks"],"dc:title":["Attack resilient GPS based timing for phasor measurement units using multi-receiver direct time estimation"],"dc:type":["text"],"thesis:degree_discipline":["Aerospace Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:34Z"}