{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/127412"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/127412","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Phase-based soil moisture sensing using radars and passive backscatter tags","abstract":"Soil moisture sensing is important to optimize water usage in agriculture and fire prevention. In agriculture, it enables smart irrigation systems to use water efficiently, reduce wastage, and enhance crop yields. For fire prevention, accurate soil moisture data improves estimates of fuel moisture levels, and helps to raise earlier wildfire warnings. Existing work on soil moisture measurement using RF signals can be categorized into contact-based and contactless methods. Contactless techniques, such as Ground Penetrating Radar (GPR), estimate soil moisture without direct soil contact but face challenges like high cost and limited signal penetration at greater heights. Contact-based methods, like burying a Wifi antenna or Lora antenna under soil, involve deploying sensors or reflectors underground, offering higher accuracy but often requiring complex setups, and high power consumption. This research introduces a hybrid system that integrates SFCW radar technology with wireless backscatter tags, offering a cost-effective, low-maintenance solution for accurate soil moisture sensing. Compared to previous RF-based approaches that buried an active and power-hungry transmitter under the soil, this approach buries a passive backscatter tag, which reflects a square wave from an active radar transmitter back to the receiver. The phase difference between the two antennas of the backscatter tag provides information about soil permittivity, which in turn indicates soil moisture. Controlled experiments demonstrate the the feasibility of inferring soil moisture from phase variations.","abstract_html":"Soil moisture sensing is important to optimize water usage in agriculture and fire prevention. In agriculture, it enables smart irrigation systems to use water efficiently, reduce wastage, and enhance crop yields. For fire prevention, accurate soil moisture data improves estimates of fuel moisture levels, and helps to raise earlier wildfire warnings. Existing work on soil moisture measurement using RF signals can be categorized into contact-based and contactless methods. Contactless techniques, such as Ground Penetrating Radar (GPR), estimate soil moisture without direct soil contact but face challenges like high cost and limited signal penetration at greater heights. Contact-based methods, like burying a Wifi antenna or Lora antenna under soil, involve deploying sensors or reflectors underground, offering higher accuracy but often requiring complex setups, and high power consumption. This research introduces a hybrid system that integrates SFCW radar technology with wireless backscatter tags, offering a cost-effective, low-maintenance solution for accurate soil moisture sensing. Compared to previous RF-based approaches that buried an active and power-hungry transmitter under the soil, this approach buries a passive backscatter tag, which reflects a square wave from an active radar transmitter back to the receiver. The phase difference between the two antennas of the backscatter tag provides information about soil permittivity, which in turn indicates soil moisture. Controlled experiments demonstrate the the feasibility of inferring soil moisture from phase variations.","abstract_has_math":false,"creators":["Yu, Angquan"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Electrical & Computer Engr","degree_department":null,"school":null,"contributors":["Soltonaghai, Elahe"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2024,"date_issued":"2024-12","date_published":"2024-12","updated_at":"2026-07-22T22:25:04Z","subjects":["Soil Moisture Sensing","Digital Signal Processing","Stepped-frequency Continuous-wave (sfcw) Radar"],"languages":["eng","en"],"rights":["©2024 Angquan Yu"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/127412","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Soltonaghai, Elahe"]},{"key":"dc:creator","label":"Author","values":["Yu, Angquan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2024-12","2024-12-11"]},{"key":"dc:type","label":"Dc Type","values":["Thesis","text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical & Computer Engr"]},{"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":["Soil Moisture Sensing","Digital Signal Processing","Stepped-frequency Continuous-wave (sfcw) Radar"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng","en"]},{"key":"dc:rights","label":"Dc Rights","values":["©2024 Angquan Yu"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/127412"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Soil moisture sensing is important to optimize water usage in agriculture and fire prevention. In agriculture, it enables smart irrigation systems to use water efficiently, reduce wastage, and enhance crop yields. For fire prevention, accurate soil moisture data improves estimates of fuel moisture levels, and helps to raise earlier wildfire warnings. Existing work on soil moisture measurement using RF signals can be categorized into contact-based and contactless methods. Contactless techniques, such as Ground Penetrating Radar (GPR), estimate soil moisture without direct soil contact but face challenges like high cost and limited signal penetration at greater heights. Contact-based methods, like burying a Wifi antenna or Lora antenna under soil, involve deploying sensors or reflectors underground, offering higher accuracy but often requiring complex setups, and high power consumption. This research introduces a hybrid system that integrates SFCW radar technology with wireless backscatter tags, offering a cost-effective, low-maintenance solution for accurate soil moisture sensing. Compared to previous RF-based approaches that buried an active and power-hungry transmitter under the soil, this approach buries a passive backscatter tag, which reflects a square wave from an active radar transmitter back to the receiver. The phase difference between the two antennas of the backscatter tag provides information about soil permittivity, which in turn indicates soil moisture. Controlled experiments demonstrate the the feasibility of inferring soil moisture from phase variations.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2026-12-01","The student, Angquan Yu, accepted the attached license on 2024-12-10 at 17:16.","The student, Angquan Yu, submitted this Thesis for approval on 2024-12-10 at 17:30.","This Thesis was approved for publication on 2024-12-11 at 09:03.","DSpace SAF Submission Ingestion Package generated from Vireo submission #21565 on 2025-03-28 at 14:45:02"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Phase-based soil moisture sensing using radars and passive backscatter tags"]}]}],"canonical_facts":{"dc:contributor":["Soltonaghai, Elahe"],"dc:creator":["Yu, Angquan"],"dc:date":["2024-12","2024-12-11"],"dc:description":["Soil moisture sensing is important to optimize water usage in agriculture and fire prevention. In agriculture, it enables smart irrigation systems to use water efficiently, reduce wastage, and enhance crop yields. For fire prevention, accurate soil moisture data improves estimates of fuel moisture levels, and helps to raise earlier wildfire warnings. Existing work on soil moisture measurement using RF signals can be categorized into contact-based and contactless methods. Contactless techniques, such as Ground Penetrating Radar (GPR), estimate soil moisture without direct soil contact but face challenges like high cost and limited signal penetration at greater heights. Contact-based methods, like burying a Wifi antenna or Lora antenna under soil, involve deploying sensors or reflectors underground, offering higher accuracy but often requiring complex setups, and high power consumption. This research introduces a hybrid system that integrates SFCW radar technology with wireless backscatter tags, offering a cost-effective, low-maintenance solution for accurate soil moisture sensing. Compared to previous RF-based approaches that buried an active and power-hungry transmitter under the soil, this approach buries a passive backscatter tag, which reflects a square wave from an active radar transmitter back to the receiver. The phase difference between the two antennas of the backscatter tag provides information about soil permittivity, which in turn indicates soil moisture. Controlled experiments demonstrate the the feasibility of inferring soil moisture from phase variations.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2026-12-01","The student, Angquan Yu, accepted the attached license on 2024-12-10 at 17:16.","The student, Angquan Yu, submitted this Thesis for approval on 2024-12-10 at 17:30.","This Thesis was approved for publication on 2024-12-11 at 09:03.","DSpace SAF Submission Ingestion Package generated from Vireo submission #21565 on 2025-03-28 at 14:45:02"],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/127412"],"dc:language":["eng","en"],"dc:rights":["©2024 Angquan Yu"],"dc:subject":["Soil Moisture Sensing","Digital Signal Processing","Stepped-frequency Continuous-wave (sfcw) Radar"],"dc:title":["Phase-based soil moisture sensing using radars and passive backscatter tags"],"dc:type":["Thesis","text"],"thesis:degree_discipline":["Electrical & Computer Engr"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:04Z"}