Everything about GPR-Scan id;activity_name;activity_type;activity_descriptor;breaching;animal;erosion;temporary;levee_survey;prolonged;start_date;end_date;date_length_day;date_length_hour;date_other;levee_stretch;location_x;location_y;location_z;location_descriptor;location_other;objectif_important;objectif_knowledge;pre_condition;act_des;monitoring_process;monitoring_reasoning;limits;during_activity;post_activity;activity_result;results_conc;knowledge_desc;ref_links;wrk_1;wrk_2;wrk_3;key_info 44;GPR-Scan;Other;Ground-penetrating radar is used to scan specific areas of the levee, then the results are compared with outputs of other surveying activities in the same areas (erosion experimentations, grout excavation, smoke injection, etc.);True;True;True;False;True;True;2021-09-07 10:01:00;2022-11-25 14:33:00;4;;4 GPR scans were realized in field on September 8th 2021, October 7th 2021 , 24 November 2021 and on the Baie de Somme in France on November 25th 2022.;Other;;;;The sub-activities contain the exact location of each scan. 3 of them were realized in the Hedwige-Prosperpolder between belgium and Netherland and one in the Baie de Somme in France;;"The GPR is a promising non destructive non intrusive tool to achieve multiple goals. In Polder2Cs the objective was to discover the opportunity of this tool by scanning specific areas in the dike with Ground-penetrating radar in order to explore the soil to different depths especially the upper layer, to make some analysis to detcect the structure of the dike and to compare later the results with other techniques applied in the same areas for detecting animal burrows, remote sensing, etc .";"- Opportunity of Using GPR for dike remote sensing and dike risk management. - Detecting animal burrows using GPR. - Analysis the doil structure";"To scan on the polder we should pay attention to the steepness of the dike , the texture of the scanned surface, the reference system of the scanned lines or grides. It is important to mesure the soil water contents. Regarding the used devices, K2Fastwave software should be already installed, configurated and prepared for for data acquisition Depending of scanning depth the suitable GPR frequency may be chosen.";"See ""During Activity Field""";Beside the scanner we used a humidity sensor. The sensor is connected to a mobile application using bluetooth, We insert the sensor in the soil, wait the measured value to be stable, record it, repeat the measurement in many points (minimum 3) in the scanned area.;The Humidity is a parameter that affect the propagation of the GPR waves. So we use a humidity sensor for monitoring.;"1) Soil Humidity: High soil humidity affects the propagation velocity of the electromagnetic waves. 2) Grass thickness and type: The thickness of the grass layer can reduce the precision of the distance measuring device that is included in the RIS ONE 2GHz radar. In addition, grass make the GPR device difficult to handle by hand. 3) Site topography: The site topography, especially steep slope, makes the movement of the GPR cart more difficult, even with the Opera Duo cart that is equipped with adapted wheels. The operator have to be careful during the scan. 4) The autonomy of the batteries of the GPR";"1- At first we identify the area 2- Regarding the wanted accuracy and the surface of the area, we can specify the spacing between the logitudinal lines (and transversal lines if necessary), then mark the lines of the grid on the soil. 3- Scan the area : - longitudinally and transversely when you use RIS ONE 2GHz. In order to adapt the RIS ONE to our experimentations, we used a wooden plate with predefined scan paths that facilitates the movement of the GPR. We can see the images of those plates in the linked data. - Parallele lines with a fixed step between the lines when you use the Opera Duo 200 MHz and 600 MHz 4- Verify that the recorded length of each scaned line in the software corresponds to the real scanned distance. 5- Save the data";"The row data obtained from the GPR scan needs to be deeply analysed to get useful information. Usually the GPR row data is analysed following 3 step process : - A SCAN : the images represent a number matrix ( on interpolating 2 dimension levels.) - B SCAN : the images are obtained from A Scan interpolation by applying filters - C SCAN : The third analysis consists on a 3D interpolation To process the data, GPR data processing softwares (GRED HD and Reflex) have to be installed and configured. The 2GHz GPR is not commonly used to scan the upper layer of the soil. The team of the university of Lille is developing a processing method to get interesting and useful results basing on this scan. This analysis procedure is partially applied on the polder2Cs row data.";We can get the row data and the A-scan immediately on the field (see post activity conditions);B and C scan (see post activity conditions);;;True;True;True; All DATA concerning GPR-Scan data_type;data_descripion;date_date;data_find;data_media;data_media_find pdf report;The Ground Penetrating Radar for inspecting levee upper layer in Polder2Cs;2022-05-03;https://stowanl-my.sharepoint.com/:b:/g/personal/llhpp_stowa_nl/ET2rYdSsAAVIpeEuy1Yb8s4BHr-8paxA9zC5CorA_PUy0A?e=tkDJjz;; All EQUIPMENTS concerning GPR-Scan equip_type;equip_usage "GPR- 2G Hz (Ground-penetrating radar). (IDS) You find some photos in the link: https://drive.google.com/drive/folders/1mFjKytG5M_yOyXRia9dahQ1txw3mjD9o?usp=sharing ";This GPR may give an accurate image for the upper layer of the soil (almost 50 Cm) "GPR- 200-600 M Hz (Ground-penetrating radar). (IDS) You find some photos in the link: https://drive.google.com/drive/folders/1cSYRQVq3BG5QiE-N0GzIGh-EQ6lTK7IZ?usp=sharing";This GPR may give an accurate image for a depth of many meters All SENSORS concerning GPR-Scan sensor_type;sensor_attributes "Humidity sensor. We use one of the following types: FDR: Frequency Domain Reflectometry TDR: Time Domain Reflectometry https://drive.google.com/drive/folders/1mFjKytG5M_yOyXRia9dahQ1txw3mjD9o?usp=sharing ";