[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-1-en-105":3,"doc-seo-240892-105":53,"doc-detail-240892-en":127},{"code":4,"msg":5,"data":6},0,"success",[7,14,19,24,29,34,39,44,49],{"id":8,"doc_module":9,"doc_module_name":10,"category_name":11,"show_sort_weight":12,"slug":13},11,1,"Template","Presentations",90,"presentations",{"id":15,"doc_module":9,"doc_module_name":10,"category_name":16,"show_sort_weight":17,"slug":18},12,"Resumes",80,"resumes",{"id":20,"doc_module":9,"doc_module_name":10,"category_name":21,"show_sort_weight":22,"slug":23},14,"Invoices",70,"invoices",{"id":25,"doc_module":9,"doc_module_name":10,"category_name":26,"show_sort_weight":27,"slug":28},15,"Posters",60,"posters",{"id":30,"doc_module":9,"doc_module_name":10,"category_name":31,"show_sort_weight":32,"slug":33},16,"Social Media",50,"social-media",{"id":35,"doc_module":9,"doc_module_name":10,"category_name":36,"show_sort_weight":37,"slug":38},17,"Forms",40,"forms",{"id":40,"doc_module":9,"doc_module_name":10,"category_name":41,"show_sort_weight":42,"slug":43},18,"Letters",30,"letters",{"id":45,"doc_module":9,"doc_module_name":10,"category_name":46,"show_sort_weight":47,"slug":48},21,"Paper Templates",5,"papers-templates",{"id":50,"doc_module":9,"doc_module_name":10,"category_name":51,"show_sort_weight":4,"slug":52},158,"General","general-158",{"code":4,"msg":54,"data":55},"ok",{"site_id":56,"language":57,"slug":58,"title":59,"keywords":60,"description":61,"schema_data":62,"social_meta":120,"head_meta":122,"extra_data":124,"updated_unix":126},105,"en","electrical-resistivity-imaging-electrical-resistivity-tomography-workflow-and-description-of-work","Electrical Resistivity Imaging (Electrical Resistivity Tomography) - Workflow and Description of Work","","Electrical Resistivity Imaging (Electrical Resistivity Tomography) uses direct-current measurements between implanted electrodes to determine subsurface electrical resistivity and map vertical and lateral variations. Low-resistivity zones indicate water-saturated ground, while air-filled voids or caves produce high-resistivity signatures. Field workflow includes satellite-based prep, electrode placement and instrument setup, dipole-dipole plus edge-gradient surveying, GPS-based location recording, data processing with EarthImager software, and multi-day interpretation and reporting.",{"@graph":63,"@context":119},[64,80,102],{"@type":65,"itemListElement":66},"BreadcrumbList",[67,71,74,77],{"item":68,"name":69,"@type":70,"position":9},"https://docshare.wps.com","Home","ListItem",{"item":72,"name":10,"@type":70,"position":73},"https://docshare.wps.com/template/",2,{"item":75,"name":11,"@type":70,"position":76},"https://docshare.wps.com/template/presentations/",3,{"item":78,"name":59,"@type":70,"position":79},"https://docshare.wps.com/template/electrical-resistivity-imaging-electrical-resistivity-tomography-workflow-and-description-of-work/240892/",4,{"url":78,"name":59,"@type":81,"image":82,"author":87,"headline":59,"publisher":90,"fileFormat":93,"inLanguage":57,"description":61,"dateModified":94,"datePublished":95,"encodingFormat":93,"isAccessibleForFree":96,"interactionStatistic":97},"DigitalDocument",{"url":83,"@type":84,"width":85,"height":86},"https://docshare.wps.com/thumbnails/electrical-resistivity-imaging-electrical-resistivity-tomography-workflow-and-description-of-work/240892.png","ImageObject",442,249,{"name":88,"@type":89},"Seraphina","Person",{"url":68,"name":91,"@type":92},"DocShare","Organization","application/pdf","2026-10-30","2026-09-11",true,{"@type":98,"interactionType":99,"userInteractionCount":101},"InteractionCounter",{"@type":100},"ViewAction",13,{"@type":103,"mainEntity":104},"FAQPage",[105,111,115],{"name":106,"@type":107,"acceptedAnswer":108},"What principle underlies an Electrical Resistivity Imaging (ERI) survey?","Question",{"text":109,"@type":110},"An ERI survey injects direct current through two metal electrodes while measuring voltage between two other electrodes, allowing subsurface resistivity differences to be determined and mapped.","Answer",{"name":112,"@type":107,"acceptedAnswer":113},"How do results help identify water and air-filled voids?",{"text":114,"@type":110},"Water or water-saturated ground produces a low-resistivity zone, while air-filled caves or pores generate a distinctive high-resistivity signature due to air’s near-infinite resistivity.",{"name":116,"@type":107,"acceptedAnswer":117},"What is the typical survey workflow from planning to reporting?",{"text":118,"@type":110},"Field preparation sets the grid and obstacles and uploads GPS/command data, followed by electrode placement and instrument setup, then GPS recording and data collection, after which data processing and interpretation take several days before a full report is written.","https://schema.org",{"og:url":78,"og:type":121,"og:title":59,"og:site_name":91,"og:description":61},"article",{"robots":123,"canonical":78},"index,follow",{"doc_id":125,"site_id":56},240892,1791748134,{"code":4,"msg":5,"data":128},{"doc_id":125,"user_id":129,"nickname":88,"user_avatar":130,"doc_module":9,"category_id":8,"category_name":11,"doc_title":59,"doc_description":61,"doc_content":131,"file_id":132,"file_url":133,"file_type":134,"file_size":135,"view_count":101,"is_deleted":4,"is_public":9,"is_downloadable":9,"audit_status":9,"page_count":76,"language":136,"language_code":57,"site_id":56,"html_lang":57,"table_of_contents":137,"faqs":138,"seo_title":139,"seo_description":61,"update_tm":140,"read_time":9},962075114101,"https://ap-avatar.wpscdn.com/avatar/e000253a75eb197efd?x-image-process=image/resize,m_fixed,w_180,h_180&k=1780044092746381165","Electrical Resistivity Imaging (also known as Electrical Resistivity Tomography)  \nElectrical resistivity (ER) surveys are a common and effective geophysical method for detection of subsurface voids and water saturated ground. The basic operating principle for an ER survey involves generating a direct current between two metal electrodes implanted in the ground while measuring the ground voltage between two other implanted electrodes (much like measuring the resistance of a circuit with a multimeter) . Given the current flow and voltage drop between the electrodes, differences in subsurface electrical resistivity can be determined and mapped. Modern resistivity surveys employ an array of multiple electrodes connected with electrical cable. Over the course of a survey, pairs of electrodes are activated by means of a switchbox and resistivity meter. The depth of investigation for atypical ER survey is approximately one-fifth the length of the array of electrodes. The near-surface resolution is roughly half of the electrode separation. The width of a survey is typically determined by the electrode separation, e.g. a four-meter electrode separation would also give an approximately eightmeter wide “strip” centered on the survey line for a 2D survey.  \nResistivity profiles illustrate vertical and lateral variations in subsurface resistivity. The presence of water or water-saturated ground will strongly affect the results of a resistivity survey by indicating a low resistivity zone. Air-filled caves or air-filled pore space provide a distinctive high resistivity signature, since air has near-infinite resistivity, in contrast with the 10 to 15 orders of magnitude more conductive surrounding bedrock.  \nFor these studies, Southwest Geophysical Consulting uses an Advanced Geosciences Inc. (AGI) SuperStingTM Wifi R8 with a multi-electrode switchbox, a 56-electrode array to image the subsurface. Surveys typically consist of a dipole-dipole survey combined with an edge gradient survey. The dipoledipole provides better resolution, while the edge gradient increases the current injected into the ground giving a better signal-to-noise ratio. Each survey will run independently, back-to-back using a combined command file. Each array consists of between 28 and 56 electrodes spaced from 1 to 5 meters apart. The exact dimensions of the array and number of electrodes are chosen to fit the parameters of the desired information about the subsurface including the desired depth and resolution. These parameters are determined through conversation with the client.  \nA Juniper Geode sub-meter GPS is used to record electrode locations and elevations, which are used during data processing to refine the image and provide location data for overlay on satellite imagery. A detailed list of each electrode number, location in latitude/longitude decimal degree format, and elevation in meters is provided as part of the data file set. EarthImager2D™ and EarthImager3D™ software are used to download and process the raw data and to provide the model used to make our interpretations.  \nWorkflow and Description of Work  \nField Preparation: Field prep consists of analysis of satellite imagery to determine grid layout and expected obstacles, survey planning, command file and GPS data upload, and inventory and packing of equipment for transport. This process takes approximately 1 day.  \nDay of Arrival: Each project will be allotted a travel day before and after the field work. If enough time exists once at the field site, ground truth of the satellite photos, area ground level photographs, and grid survey and set-up will be conducted. Otherwise, these processes will take place at the beginning of the first full day of the survey.  \nSurvey setup includes visually marking the survey boundaries and measuring out each of the survey lines perpendicular to the long edge of the survey area. The electrodes are then placed at the selected interval along the survey tape and the electro","cbCaidHvxhBjgeSi","https://ap.wps.com/l/cbCaidHvxhBjgeSi","pdf",304353,"English","# Field Preparation\n# Day of Arrival\n## Survey setup and equipment operation\n# Final Day\n# Interpretation and Report","[{\"question\":\"What principle underlies an Electrical Resistivity Imaging (ERI) survey?\",\"answer\":\"An ERI survey injects direct current through two metal electrodes while measuring voltage between two other electrodes, allowing subsurface resistivity differences to be determined and mapped.\"},{\"question\":\"How do results help identify water and air-filled voids?\",\"answer\":\"Water or water-saturated ground produces a low-resistivity zone, while air-filled caves or pores generate a distinctive high-resistivity signature due to air’s near-infinite resistivity.\"},{\"question\":\"What is the typical survey workflow from planning to reporting?\",\"answer\":\"Field preparation sets the grid and obstacles and uploads GPS/command data, followed by electrode placement and instrument setup, then GPS recording and data collection, after which data processing and interpretation take several days before a full report is written.\"}]","Electrical Resistivity Imaging (Electrical Resistivity Tomography) - Workflow and Description of Work | PDF",1789167329]