Ground Penetrating Radar (GPR) images highly depend on the relative geometry existing between the transmitting and receiving antennas and the depth reflectors. The resulting variations are mainly due to the directional properties of the antennas and also to the sensitivity of the considered reflector to the polarization of the incident electromagnetic wave. In the present study, GPR data sets have been recorded using several 100 MHz antenna configurations, including Transverse Electric (TE) and Transverse Magnetic (TM) modes. In addition, a polarization analysis has been conducted by surveying twice the studied profile in both modes (TE and TM), using parallel and perpendicular antennas. The obtained images display a high complementarity that provides more details on the studied geological structures when compared to an image derived from a single conventional acquisition configuration. These studies emphasize how multi-configuration antennas surveys have the potential to improve GPR imaging and interpretation. Furthermore, polarimetric surveys have been carried out in order to study the possible link between interface depolarization phenomenon and phase wave inversion and amplitude wave decrease observed for TE Common Mid Point gathers. The latter would induce disturbances of the GPR images when stacking procedures are used for multi-offsets surveys.
{"title":"Influence of antenna configurations on 2D GPR data: Information from polarization and amplitude measurement","authors":"P. Lutz, H. Perroud, S. Garambois","doi":"10.1117/12.462196","DOIUrl":"https://doi.org/10.1117/12.462196","url":null,"abstract":"Ground Penetrating Radar (GPR) images highly depend on the relative geometry existing between the transmitting and receiving antennas and the depth reflectors. The resulting variations are mainly due to the directional properties of the antennas and also to the sensitivity of the considered reflector to the polarization of the incident electromagnetic wave. In the present study, GPR data sets have been recorded using several 100 MHz antenna configurations, including Transverse Electric (TE) and Transverse Magnetic (TM) modes. In addition, a polarization analysis has been conducted by surveying twice the studied profile in both modes (TE and TM), using parallel and perpendicular antennas. The obtained images display a high complementarity that provides more details on the studied geological structures when compared to an image derived from a single conventional acquisition configuration. These studies emphasize how multi-configuration antennas surveys have the potential to improve GPR imaging and interpretation. Furthermore, polarimetric surveys have been carried out in order to study the possible link between interface depolarization phenomenon and phase wave inversion and amplitude wave decrease observed for TE Common Mid Point gathers. The latter would induce disturbances of the GPR images when stacking procedures are used for multi-offsets surveys.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126521370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Large quantities of non-aqueous phase liquids (NAPL), contaminate the near surface sediments at Operable Unit 1 (OU1), Hill Air Force Base (HAFB), Utah. In October 2000, a 3D, multi-offset GPR survey was acquired at OU1 with two objectives: (1) to image the aquifer/aquitard boundary at a depth of about 30 ft, and (2) to evaluate quantitative processing and interpretation methodologies for direct detection of NAPL. Using pre-stack depth migration, we map the aquitard boundary to about {+-} 1 ft throughout the survey area. An unusual reflection is identified within the vadose zone that does not correlate with known geology. The region below this reflection has anomalously high velocity, implying low electric permittivity, and the amplitude of the anomalous reflection deviates significantly from the background AVO trend. Fitting the Fresnel equation to the AVO data, we estimate the velocity contrast at the anomaly boundary and find that it is in good agreement with the migration velocity model. We interpret the anomaly as a previously unidentified NAPL rich zone. Subsequent coring and chemical analyses verify our interpretation. This exciting result implies that these methodologies may be useful for direct detection of NAPL at other HAFB locations and at sites with similar hydrogeology.
{"title":"Characterization of an aquitard and direct detection of LNAPL at Hill Air Force Base using GPR AVO and migration velocity analyses","authors":"J. Deeds, J. Bradford","doi":"10.1117/12.462236","DOIUrl":"https://doi.org/10.1117/12.462236","url":null,"abstract":"Large quantities of non-aqueous phase liquids (NAPL), contaminate the near surface sediments at Operable Unit 1 (OU1), Hill Air Force Base (HAFB), Utah. In October 2000, a 3D, multi-offset GPR survey was acquired at OU1 with two objectives: (1) to image the aquifer/aquitard boundary at a depth of about 30 ft, and (2) to evaluate quantitative processing and interpretation methodologies for direct detection of NAPL. Using pre-stack depth migration, we map the aquitard boundary to about {+-} 1 ft throughout the survey area. An unusual reflection is identified within the vadose zone that does not correlate with known geology. The region below this reflection has anomalously high velocity, implying low electric permittivity, and the amplitude of the anomalous reflection deviates significantly from the background AVO trend. Fitting the Fresnel equation to the AVO data, we estimate the velocity contrast at the anomaly boundary and find that it is in good agreement with the migration velocity model. We interpret the anomaly as a previously unidentified NAPL rich zone. Subsequent coring and chemical analyses verify our interpretation. This exciting result implies that these methodologies may be useful for direct detection of NAPL at other HAFB locations and at sites with similar hydrogeology.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120901226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have designed and developed a borehole radar, which has a directional radiation pattern and fits in a single borehole. A 3D image of the subsurface is obtained by applying a linear inversion scheme on the data, in which we deconvolve for the computed radiation pattern.
{"title":"Directional borehole radar for three-dimensional imaging","authors":"K. V. van Dongen, P. M. van den Berg, J. Fokkema","doi":"10.1117/12.462211","DOIUrl":"https://doi.org/10.1117/12.462211","url":null,"abstract":"We have designed and developed a borehole radar, which has a directional radiation pattern and fits in a single borehole. A 3D image of the subsurface is obtained by applying a linear inversion scheme on the data, in which we deconvolve for the computed radiation pattern.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125253570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
roadbeds using multi-channel GPR is described. GPR is a continuous and non-destructive method and its capabilities of providing information on soil and water content is well documented in the past. Most of these earlier described methods involve several time consuming measurements with a variety of antenna settings. A multi-channel radar system can however make more efficient measurements through the use of independently controlled transmitters and receivers in the antenna array. The results, from measurements with a 500 MHz GPR system, show a clear correlation between the GPR data and the soil water content in a Swedish roadbed. Further evaluation is, however, needed to compare different antenna frequencies and to calibrate the equipment together with reference velocity analysis.
{"title":"Simple method for estimation of water content of roadbeds using multi-offset GPR","authors":"J. Emilsson, P. Englund, J. Friborg","doi":"10.1117/12.462223","DOIUrl":"https://doi.org/10.1117/12.462223","url":null,"abstract":"roadbeds using multi-channel GPR is described. GPR is a continuous and non-destructive method and its capabilities of providing information on soil and water content is well documented in the past. Most of these earlier described methods involve several time consuming measurements with a variety of antenna settings. A multi-channel radar system can however make more efficient measurements through the use of independently controlled transmitters and receivers in the antenna array. The results, from measurements with a 500 MHz GPR system, show a clear correlation between the GPR data and the soil water content in a Swedish roadbed. Further evaluation is, however, needed to compare different antenna frequencies and to calibrate the equipment together with reference velocity analysis.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122588828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Radar reflections for a layered medium are dependant on the dielectric constants of the layers, which is closely linked to saturated porosity, and more loosely to hydraulic conductivity. Radar data have been obtained at a site where hydraulic conductivity has been measured in great detail. The radar cross section from the site clearly shows layering within the section, and it is tantalizing to predict that the hydraulic conductivities also persist along the bedding surfaces. The radar trace may be converted to a band limited pseudo-dielectric constant log by the same methods used to estimate an acoustic velocity log in seismic work. Thus, the resulting dielectric constant section can be converted to pseudo-porosity and pseudohydraulic conductivity displays. But, because of the limited bandwidth of the radar signal, it is tricky to invert the radar traces to yield dielectric constant and ultimately hydraulic conductivity. The main computations are 1. deconvolution with Seismic Unix routines and 2. conversion to dielectric constant including filtering to minimize numerical instabilities.
{"title":"Estimating hydrogeologic parameters from radar data","authors":"C. Young","doi":"10.1117/12.462251","DOIUrl":"https://doi.org/10.1117/12.462251","url":null,"abstract":"Radar reflections for a layered medium are dependant on the dielectric constants of the layers, which is closely linked to saturated porosity, and more loosely to hydraulic conductivity. Radar data have been obtained at a site where hydraulic conductivity has been measured in great detail. The radar cross section from the site clearly shows layering within the section, and it is tantalizing to predict that the hydraulic conductivities also persist along the bedding surfaces. The radar trace may be converted to a band limited pseudo-dielectric constant log by the same methods used to estimate an acoustic velocity log in seismic work. Thus, the resulting dielectric constant section can be converted to pseudo-porosity and pseudohydraulic conductivity displays. But, because of the limited bandwidth of the radar signal, it is tricky to invert the radar traces to yield dielectric constant and ultimately hydraulic conductivity. The main computations are 1. deconvolution with Seismic Unix routines and 2. conversion to dielectric constant including filtering to minimize numerical instabilities.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127659518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The detection of discrete anomalies, such as cavities and tunnels, is an important application of crosshole radar tomography. However, tomographic inversion results are frequently ambiguous showing smearing effects and artifacts. This leads to uncertainties during interpretation and, hence, the size and shape of discrete anomalies can be interpreted only with limited accuracy and reliability. In this study, we present an adapted inversion strategy for the detection of discrete anomalies with crosshole tomography. For tomographic inversion, we use various partial data sets of specified angular aperture. The resulting tomograms contain different information with respect to the vertical and horizontal resolution of discrete anomalies. Ambiguities, such as smearing and artifacts, can be recognized and considered during interpretation. From this, an adapted starting model is derived combining all additional information. Although the tomographic inversion results for different starting models differ significantly regarding the resolution characteristics of anomalies, the rms residuals are equivalent. Therefore, we additionally investigate the angular contribution of the residuals to the rms values, and propose another optimization criterion, the relative data misfit. It is shown, that the angular contribution of the residuals reflects the resolution characteristics of the tomograms.
{"title":"Advanced processing of cross-hole radar-tomographic data: inversion of partial data sets and error analysis","authors":"A. Becht, E. Appel, P. Dietrich","doi":"10.1117/12.462271","DOIUrl":"https://doi.org/10.1117/12.462271","url":null,"abstract":"The detection of discrete anomalies, such as cavities and tunnels, is an important application of crosshole radar tomography. However, tomographic inversion results are frequently ambiguous showing smearing effects and artifacts. This leads to uncertainties during interpretation and, hence, the size and shape of discrete anomalies can be interpreted only with limited accuracy and reliability. In this study, we present an adapted inversion strategy for the detection of discrete anomalies with crosshole tomography. For tomographic inversion, we use various partial data sets of specified angular aperture. The resulting tomograms contain different information with respect to the vertical and horizontal resolution of discrete anomalies. Ambiguities, such as smearing and artifacts, can be recognized and considered during interpretation. From this, an adapted starting model is derived combining all additional information. Although the tomographic inversion results for different starting models differ significantly regarding the resolution characteristics of anomalies, the rms residuals are equivalent. Therefore, we additionally investigate the angular contribution of the residuals to the rms values, and propose another optimization criterion, the relative data misfit. It is shown, that the angular contribution of the residuals reflects the resolution characteristics of the tomograms.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114663276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Lorenzo, P. Arias, M. C. Hernàndez, S. Alvarez, T. Teixeira
The importance of archaeological heritage justifies looking for new techniques and methods which allow their knowledge in a more exhaustive way. We are not only talking about detection, but also about remains geometry and construction details. Cultural heritage record documents should include all possible information and the collection of this non-destuctive techniques information is recommended (Neubauer, 2001). In this work we show the preliminary results obtained applying three techniques at an archaeological site in Galicia (Spain), in order to document the remains of a megalithic tomb. First of all, a full topographic total station survey was made to obtain a digital terrain model of the studied area. The GPR investigation was made with Zond- 12c equipment operating with a 900 MHz antenna, radargrams were corrected with the digital terrain data attained hefore. The results showed a very shallow reflector on the top of a small hummock (15 m diameter, 3 m high), very close to an emerging flagstone which could be a part of the tomb. Excavation makes evident the presence of some other flagstones of the tomb at this point. The full archaeological site was excavated and a close-range photogrammetric study was made to obtain a cultural heritage record document including all possible metric information of the remains. A calibrated digital camera was used to obtain the spatial representation of the tomb. This information may be used in the future to reconstruct the tomb in another place, because the contruction of a new highway crossing at this archaeological site is going to take place at some future stage.
{"title":"Ground-based radar, close-range photogrammetry, and digital terrain data applied together to archaeological heritage documentation","authors":"H. Lorenzo, P. Arias, M. C. Hernàndez, S. Alvarez, T. Teixeira","doi":"10.1117/12.462199","DOIUrl":"https://doi.org/10.1117/12.462199","url":null,"abstract":"The importance of archaeological heritage justifies looking for new techniques and methods which allow their knowledge in a more exhaustive way. We are not only talking about detection, but also about remains geometry and construction details. Cultural heritage record documents should include all possible information and the collection of this non-destuctive techniques information is recommended (Neubauer, 2001). In this work we show the preliminary results obtained applying three techniques at an archaeological site in Galicia (Spain), in order to document the remains of a megalithic tomb. First of all, a full topographic total station survey was made to obtain a digital terrain model of the studied area. The GPR investigation was made with Zond- 12c equipment operating with a 900 MHz antenna, radargrams were corrected with the digital terrain data attained hefore. The results showed a very shallow reflector on the top of a small hummock (15 m diameter, 3 m high), very close to an emerging flagstone which could be a part of the tomb. Excavation makes evident the presence of some other flagstones of the tomb at this point. The full archaeological site was excavated and a close-range photogrammetric study was made to obtain a cultural heritage record document including all possible metric information of the remains. A calibrated digital camera was used to obtain the spatial representation of the tomb. This information may be used in the future to reconstruct the tomb in another place, because the contruction of a new highway crossing at this archaeological site is going to take place at some future stage.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126321588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For the imaging of ground-penetrating radar (GPR) data, the form of the radar wavelet is usually not taken into account, because the behaviour of actual source and receiver antennas, that have a large influence on the wavelet, is rather complex. Nevertheless, knowledge of the wavelet has the potential to improve the imaging and interpretation of GPR data. An efficient way to deal with the wavelet is proposed by introducing an effective wavelet that incorporates the influence of the finite-length antennas. To obtain this effective wavelet, the impulse response for a point source-receiver antenna system is calculated using the medium properties, that are obtained from the isolated air- and ground-waves observed on the actual CMP data. The deconvolution of this impulse response with the actual CMP data, yields an effective wavelet. Together with the well-known radiation characteristics of dipole antennas in a dielectric halfspace, the propagation of the electromagnetic waves emitted a finite-length source-receiver antenna system can be effectively described. We demonstrate that propertiesof the shallow subsurface can be extracted from the ground-wave with reasonable accuracy. An effective wavelet determined from numerical data calculated for a finite-length source-receiver antenna system shows an effective wavelet that is less minimum phase than the effective wavelet calculated from the electric field generated by a point source-receiver antenna system.
{"title":"Effective source wavelet determination","authors":"J. van der Kruk, E. Slob","doi":"10.1117/12.462231","DOIUrl":"https://doi.org/10.1117/12.462231","url":null,"abstract":"For the imaging of ground-penetrating radar (GPR) data, the form of the radar wavelet is usually not taken into account, because the behaviour of actual source and receiver antennas, that have a large influence on the wavelet, is rather complex. Nevertheless, knowledge of the wavelet has the potential to improve the imaging and interpretation of GPR data. An efficient way to deal with the wavelet is proposed by introducing an effective wavelet that incorporates the influence of the finite-length antennas. To obtain this effective wavelet, the impulse response for a point source-receiver antenna system is calculated using the medium properties, that are obtained from the isolated air- and ground-waves observed on the actual CMP data. The deconvolution of this impulse response with the actual CMP data, yields an effective wavelet. Together with the well-known radiation characteristics of dipole antennas in a dielectric halfspace, the propagation of the electromagnetic waves emitted a finite-length source-receiver antenna system can be effectively described. We demonstrate that propertiesof the shallow subsurface can be extracted from the ground-wave with reasonable accuracy. An effective wavelet determined from numerical data calculated for a finite-length source-receiver antenna system shows an effective wavelet that is less minimum phase than the effective wavelet calculated from the electric field generated by a point source-receiver antenna system.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125490368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Although GPR is normally capable of detecting the responsefrom buried plant, accurate detection and mapping of extended geometrical features in 3-dimensional data is often a major problem faced by the radar operators and geophysicists. This paper presents a pattern recognition approach based on the 3-dimensional Hough Transform for the detection of extended linear targets. By transforming spatially extended patterns into spatially compact features in parameter space, a difficult global detection problem in data space becomes a more easily solved local peak detectionproblem in parameter space. This technique allows the combination of qualitative site information and ground truth in order to increase the accuracy of the final result. Improved freedom of movement and accuracy is achieved by logging the movement of the GPR unit using DGPS. The user is presented with a 3-dimensional site survey report detailing the length, depth and orientations (azimuth and zenith) of any pipes, cables or the like.
{"title":"Automatic 3D mapping of features using GPR","authors":"W. Al-Nuaimy, H. Lu, S. Shihab, A. Eriksen","doi":"10.1117/12.462225","DOIUrl":"https://doi.org/10.1117/12.462225","url":null,"abstract":"Although GPR is normally capable of detecting the responsefrom buried plant, accurate detection and mapping of extended geometrical features in 3-dimensional data is often a major problem faced by the radar operators and geophysicists. This paper presents a pattern recognition approach based on the 3-dimensional Hough Transform for the detection of extended linear targets. By transforming spatially extended patterns into spatially compact features in parameter space, a difficult global detection problem in data space becomes a more easily solved local peak detectionproblem in parameter space. This technique allows the combination of qualitative site information and ground truth in order to increase the accuracy of the final result. Improved freedom of movement and accuracy is achieved by logging the movement of the GPR unit using DGPS. The user is presented with a 3-dimensional site survey report detailing the length, depth and orientations (azimuth and zenith) of any pipes, cables or the like.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133883069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To ease geological investigations with GPR (Ground Penetrating Radar) in rough terrain, the GPR equipment can be combined with a carrier-phase DGPS (Differential GPS). As traditional communication with GPS (with e.g., the NMEA protocol) involves an inherent time delay, a new method has been constructed to synchronize the measuring with GPS and GPR units in which the GPS is transmitting a trig signal to the GPR. The results of this case study clearly shows that combining GPR- and DGPS-measurements gives an investigation without need of initial land surveying or clearing of obstacles and vegetation. The investigation also gives information of the topography, which allows for a volume estimation of the investigated target, in this case a limestone layer.
{"title":"Geological mapping using GPR and differential GPS positioning: a case study","authors":"J. Aaltonen, J. Nissen","doi":"10.1117/12.462245","DOIUrl":"https://doi.org/10.1117/12.462245","url":null,"abstract":"To ease geological investigations with GPR (Ground Penetrating Radar) in rough terrain, the GPR equipment can be combined with a carrier-phase DGPS (Differential GPS). As traditional communication with GPS (with e.g., the NMEA protocol) involves an inherent time delay, a new method has been constructed to synchronize the measuring with GPS and GPR units in which the GPS is transmitting a trig signal to the GPR. The results of this case study clearly shows that combining GPR- and DGPS-measurements gives an investigation without need of initial land surveying or clearing of obstacles and vegetation. The investigation also gives information of the topography, which allows for a volume estimation of the investigated target, in this case a limestone layer.","PeriodicalId":256772,"journal":{"name":"International Conference on Ground Penetrating Radar","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122885965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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