- Home
- Conferences
- Conference Proceedings
- Conferences
9th EAGE/EEGS Meeting
- Conference date: 31 Aug 2003 - 04 Sep 2003
- Location: Prague, Czech Republic
- ISBN: 978-94-6282-116-3
- Published: 01 September 2003
1 - 100 of 180 results
-
-
2-D data modelling by electrical resistivity tomography for complex subsurface geology (is it possible to improve electronic interpretation of resistivity measurements with multielectrode devices in undeterminated cases?)
Authors E. Cardarelli and F. FischangerIn the last years, there has been a widespread increase in the use of 2-D electrical methods surveys especially due to the development of automatically multiplexed measuring systems which facilitate the acquisition of a large number of measurements. These methods are mainly used to map area with complex subsurface geology, to study aquifers, and to identify covered structures in archaeological study. For this reason the interpretation and consequently the inversion procedure of electric methods has to be accurate.
-
-
-
Geoinformation system of Czech Geological Survey - Geofond
By D. CápováBy decree of the Minister of Environment of the Czech Republic the organization of the Czech Geological Survey consists of two organizations under the direction of the Ministry of Environment: the Czech Geological Survey (CGS), and the Czech Geological Survey - Geofond (Geofond).
-
-
-
Applications and modelling of high sensitivity potassium gradiometers for near surface geophysics
Authors I. Hrvoic, G. M. Hollyer, R. Groom, R. Jia and A. SzetoNear surface geophysical methods and their role in Archaeology; Environmental and Engineering; and Unexploded Ordnance Detection applications is migrating from "anomaly detection" to characterization. With this trend, some instrument manufacturers are conducting research and development in to equipment capable of resolving targets more effectively. This paper focuses on the development and field testing of GEM'S new Optically Pumped Potassium system. The new technology provides high sensitivity; rapid sampling and high bandwidth; and "clean" geophysical signal (i.e. low heading error). Gradient tolerance is also enhanced.
-
-
-
Analysis of noise coherence in airborne magnetic gradients for UXO detection
Authors T. J. Gamey, W. E. Doll, L. P. Beard and D. T. BellIn boom-mounted magnetometer systems, the primary noise falls into two main categories: maneuver noise and rotor noise. The forrner is relatively low Frequency, while the latter is relatively high frequency. Frequency filters of various types have been used with success, but fall short where the noise is within the bandwidth of the signal. Such is often the case when searching for unexploded ordnance (UXO) and other shallow targets at rapid flight speeds. Under these conditions, helicopter noise can be reduced by making use of the fact that much of it is coherent between sensors. In this paper, we examine the coherence of various types of helicopter noise and demonstrate that measured vertical gradients can offer raw signal-tonoise improvements of 4:1 or more over comparable total field measurements.
-
-
-
Geophysical investigations for groundwater in the lower Klamath Lake basin, Oregon
Authors R. B. French, M. D. Jenks and G. G. ConnardSince the early 1900's the Klamath Basin, in the western United States, has relied heavily on surface water for irrigation. A large infrastructure of dams, canals and pump stations has been developed to service approximately 1500 farms. In the summer of 2001, with drought conditions and a concern for endangered species, the United States Bureau of Reclamation completely cutoff all irrigation water from Upper Klamath Lake, leaving approximately 1500 farms without water for crops. A flurry of groundwater exploration ensued.
-
-
-
Applying airborne electromagnetic induction in ground-water salinization and resource studies, West Texas
Authors J. G. Paine and E. W. CollinsIn 2001, two high-resolution airbome geophysical surveys were flown in West Texas using Fugro's MEGATEM II system to acquire time-domain EM (TDEM) and magnetic field data. One survey, flown at 100-m line spacing on the Edwards Plateau, identified and assessed groundwater salinization in an oil-field area. The second survey, flown at 400-m line spacing over a West Texas basin, identified favorable areas for groundwater exploration.
-
-
-
Lamb wave analysis for non-destructive testing of concrete plate structures
Authors N. Ryden, Ch. B. Park, P. Ulriksen and R. D. MillerLamb waves are guided dispersive waves propagating in free plate structures (Lamb, 1917). By matching theoretical multimodal Lamb wave dispersion curves with experimental ones, shear wave velocity (Vs), Poisson's ratio (v), and thickness (d) of the tested plak structure can be evaluated. In this expanded abstract a practical approach for NDT of pavements and concrete structures utilizing multiple modes of Lamb wave dispersion curves is presented. Both the measuring procedure and the analysis scheme is described. A complete description of how to calculate theoretical Lamb wave dispersion curves and more details on this study were given in the original manuscript (Ryden et al. 2003).
-
-
-
Outlook on the possibility for slope stability evaluation according to petrophysical data
Authors A. Frasheri, F. Dhima and B. CangaResults of the geophysical data for in-situ evaluation of the physical-mechanical properties of the rocks in the unstable slopes in Albania are presented.
-
-
-
Application of 2D laterally constrained inversion and 2D smooth inversion of CVES resistivity data in a slope stability investigation
Authors R. Wisén, A. V. Christiansen, E. Auken and T. DahlinIn this paper we present how a 2D least squares algorithm, Res2Dinv (Loke and Dahlin, 2002), and the 2D Lateral Constrained Inversion (2D-LCI) algorithm (Christiansen et al., 2003) can be applied in geotechnical site investigations. The 2D-LCI algorithm performs a parameterized 2D Laterally Constrained Inversion (Auken and Christiansen, 2003) on resistivity data.
-
-
-
Ground penetrating radar investigation of limestone cliff fracturing in the French Alps
Authors M. Jeannin, S. Garambois, D. Jongmans and C. GrégoireAmong many natural hazards, rock falls are a very frequent phenomenon in mountainous areas, characterized by its suddenness and its difficulty to predict. The growing urbanisation in these areas implies-to better assess this hazard, and consequently to determine the location and volume of a rock mass which could fall. The stability assessment of a rock mass is generally based on surface observations (slope morphology, structural properties of the massif, deformation measurements). Even if these studies are necessary, the lack of information within the rock mass and, particularly, on discontinuities (geometry, properties) leads to major problems in hazard assessment.
-
-
-
New achievements in developing a high speed geoelectrical monitoring system for landslide monitoring
More LessLandslides are one of the major threats to human settlements and infrastructure, causing over time enormous human suffering and property losses than any other geological hazard. Especially in alpine regions, population pressure has prompted settlement to more extreme areas, which are, due to their geological settings, vulnerable to landslides. Therefore much effort has to be centred on risk detection, risk reduction and development of timely waming systems to prevent future loss of life and property.
-
-
-
Seismic tomography to explore cleft zones below houses in the area of a stress system induced by deep coal mining activities
Authors D. Orlowsky, U. Hunfeld and B. LehmannDue to deep coal mining activities dwing the years from 1980 to 2000 in depths between 700 and 1000 m a local stress systcm was induced in the northern part of the Ruhr Area in Germany. Atter strong rainfall in November 2002 this stress system leads to visible clefts at the earth's surface (Figure 1) with a lateral extension of the cleft zone of more than 250 m over arable soil along a country road and directly below a house. To explore the cleft zone below the house the seismic tomography was used to detemine it's extension and dip and additionally to investigate if the cleft zone may have significant influence on the stability of the underground below the house fundaments.
-
-
-
Satellite radar interferometry and reflection seismic: An integrated geophysical study on the great Ancona landslides
Authors A. Mazotti and F. RoccaThe Great Ancona Landslide is located in the Italian Adriatic coast, immediately westward of the harbour city of Ancona and interests an area of about 3.5 km2, with a landslide front of about 2 km. (Figure IA). It is an ancient landslide, its occurrence being known since 1700. In recent times, the most severe event took place on December 13th 1982, when a densely built section of the city was involved in the eastern part of the landslide.
-
-
-
Hydroacoustic monitoring in the Tressange pilot site (Moselle, France)
By S. BernardieThe purpose of this study is to implement a new technique for monitoring the abandoned mines subjected to flooding: it consists of a hydroacoustic monitoring (sensor placed in water filling the mining cavity) in a broad frequency bandwidth (30 Hz-1 80 kHz). GISOS, a French scientific interest group concerned with the impact and the safety of the underground works in the field of the post-mining, aims amongst other at understanding the phenomena occurring in the old mining cavities in order to forecast their evolution. A very significant research effort is put on the monitoring methods for assessing degradation of the mining works, as they directly threaten the infrastructures located on the ground surface. One of the parameters, which have a significant role in the stability of the underground works, is water.
-
-
-
Using geophysical methods to image the internal structure of mine waste rock piles
Authors D. Campos, M. Chouteau, M. Aubertin and B. BussiéreMine waste rock piles, or rockwaste dumps, containing metallic sulphides are a favourable environment for the generation of acid mine drainage (AMD). There are many physical, geochemical and biological processes that lead to the production of AMD within waste rock piles. One of the most critical of these is water flow and water distribution in the waste rock. To fully understand this process, it is critical to know the intemal structure of waste rock piles. In this paper, the authors show the results of an investigation where resistivity and ground penetrating radar (GPR) geophysical methods have been used to study mine dumps.
-
-
-
Using seismic refraction and 2-D electrical imaging methods to detect boulders in Penang, Malaysia
Authors R. Saad, M. N. M. Nawawi and Z. Z. T. HarithThe hot and wet condition are the main factor in speeding-up the physical and chemical weathering process, as well as creating fractures on the rock. Further erosion and weathering will cause the rock to break into boulders, and eventually form a thick blanket of soil. The occurrence of landslide in Malaysia is believed primarily due to the unusual thick soil profile and high rainfall. Buried boulders can also disrupt civil engineering projects especially piling and hill cutting.
-
-
-
Czech environmental and engineering geophysics
More LessThe geophysical methods in geotechnics, hydrogeology and in environment have a relatively rich tradition in the Czech Republic. The first geoelectrical measurement for the soil investigation and for the dam place choice was made in the years 1940 and 1941 by the doyen of Czech geophysicists Rudolf Bghounek, later the first professor for applied geophysics at the Natural Faculty in Charles University.
-
-
-
Comparative study between the shallow seismic refraction and laboratory methods for detecting the mechanical properties of some limestone rocks
Authors A. Heleika and G. M. E. KamhDetermination of the mechanical parameters of rocks and soil are very useful for building and other civil engineering purposes, but the mechanical properties of sedimentary rocks have wide range of values and are much influenced by lithological factors. These parameters are usually measured in the laboratory from some collected samples. These samples not reflect the mechanical behavior of the whole rocks. In this work a comparative study for measuring the mechanical properties of some Eocene Limestone rocks along four selected sites by using the shallow refraction seismic method and the laboratory method had been carried out for judging which one is suitable for this purpose.
-
-
-
Experimental seismic measurements with the application of a vibrator
Authors J. Vilhelm, J. Skopec and J. BártaSince 2001, grant of the Ministry of Transport and Communications of the Czech Republic "Application of Geophysical Methods for Checking the Condition of Czech Railway Tracks" includes geophysical measurements that are performed by the grant holder - G IMPULS Praha s.r.0. in cooperation with Charles University, Faculty of Science, Prague.
-
-
-
Application of geophysical methods for checking the condition of Czech Railway tracks
More LessOn the basis of the decision of the Ministry of Transport and Communications of the Czech Republic on the provision of financial resources, the following grant was commenced in 2001 and will be completed in 2003: "Application of Geophysical Methods for Checking the Condition of Czech Railway Tracks".
-
-
-
Resistivity monitoring for leakage detection at Hällby embankment dam
Authors P. Sjödahl, T. Dahlin and S. JohanssonIntemal erosion is one of the major reasons for embankment dam failures. Resistivity monitoring may have the possibility of detecting internal erosion processes and anomalous seepage at an early stage before the safety of the dam is at stake. This is done by analysing and comparing the seasonal resistivity variation schemes in the reservoir and inside the dam body. The technique is essentially non-destructive, which is particularly important when working with embankment dams where drilling and other penetrating investigations are normally avoided.
-
-
-
Multi-electrode measurements at Thai Binh dikes (Vietnam)
Authors T. Canh, N. Trong Vu and A. WellerAbout 7000 km river dikes and sea dikes have been built in the northem provinces of Vietnam. Annually, Vietnamese govemment and people have spent a lot of money for maintenance and protection of the dike system against flooding. Nevertheless, breaks of the dikes still happen, which have serious consequences. The instability of dikes results from defects, termite nests, seepage effects, or distorted dike foundation. The origin of these effects is usually hidden in the dike's body or foundation. It is not directly visible. Methods of dike monitoring are necessary to assess the stability and the state of the dike.
-
-
-
Geophysical applications to geotechnical projects in Australia and China
By B. WhiteleyCivil engineers use geophysics for site characterisation to reduce geotechnical risks associated with construction by improving the accuracy of geotechnical models and to provide design parameters. Unlike exploration geophysics where successful outcomes, i.e. new discoveries are improbable, geotechnical engineers always expect successful outcomes with geophysical interpretations accurately representing the subsurface.
-
-
-
Geothermal planning maps based on geophysical measurements
Authors R. Kirsch, D. Eberle, B. Röttger, B. Siemon and W. VossThe use of near surface geothermal energy is not based on the temperature increase with increasing depth, but on the fact that under normal conditions no seasonal temperature differences are present at depths exceeding 10 m. Below that depth temperatures are 10 - 12°C all over the year. So subsurface temperatures are cooler in summer and warmer in the winter than surface temperature. This can be used for cooling purposes in the summer, and, using a heat pump, for heating in the winter (Fig. 1).
-
-
-
Application of the 2-D resistivity tomography, electromagnetic profiling method and soil thermometry for a remedy of the existing road endangered by the slope instability shallow caves and other inhomogeneities in the karst area
More LessThe geophysical survey was carried out in Moravian Karst - the well-known national park of the Czech Republic that extends to the northeast from Brno city. This not very large but wonderful landscape is characterized by very high stage of karstification on one side and by intensive human activity from early age till these days on the other side. (There are many caves, sinkholes, rocky gorges and abysses as well as prehistoric stations, several castles, villages and remains of old industrial activities.)
-
-
-
Dispersion diagram analysis for underground cavitie : A finite difference approach
Authors C. Gelis, D. Leparoux, J. Virieux, A. Bitri and S. OpertoIdentifiing physical phenomena induced by underground cavities on seismic surface waves will improve void detection methods involving surface seismic waves. Recent works (Leparoux et al., 2000) based on numerical analysis in elastic media with 2nd order finite differences method (Virieux, 1986) and experimental validation show the capability of Rayleigh waves to detect underground cavities, as well as other works (Shtivelman (2000)). Nevertheless, these results show the necessity of accurate numerical modelling taking into account weathered structures and different shapes of cavity. A new finite difference spatial stencil has been proposed by Saenger et al. (2000) for reducing numerical dispersion. After describing this numerical method applied to surface waves analysis, we present seismograms and dispersion diagrams for different cavity typlogies and shot gathers.
-
-
-
Experimentation at a test site for detecting voids and buried objects with seismic methods
Authors D. Leparoux, G. Grandjean, O. Abraham and P. CoteThe presence of man-made and natural buried objects - and particularly voids - in the subsurface is a recurring problem in civil engineering and landscape management. For the past few years, and in conjunction with other classical methods, we have been testing the potential of seismic methods for detecting underground voids based on the techniques of P-wave reflection (Grandjean et al., 2002) and surface-wave diffraction (Leparoux et al., 2000).
-
-
-
2D Resistivity imaging at the Alba Iulia citadel, Romania
Authors R. Lachapelle and C. Suteu2D Electrical resistivity imaging has been successfully used as a subsurface investigation tool in engineering and environmental investigations. We present the results of a 2-D resistivity imaging survey over a buried tunnel.
-
-
-
Microgravity detection of the chambers caused by a battery breast coal mining
By V. BlechaThe area of study is located in the Northem Bohemia in the immediate vicinity of the Most town. The region is a traditional territory of brown coal mining. Horizontal and subhorizontal coal seams in the Tertiary sedimentary basin are surrounded by clays and claystones.
-
-
-
High-resolution seismic reflection data reveal major fault zone in Lake Geneva, Switzerland
Authors F. Marillier, D. Dupuy, C. Proietti and M. ScheidhauerAlong the northern rim of the Swiss Alps, a major thrust fault zone separetes Plateau Molasse to the northwest fiom Subalpine Molasse to the southeast. This feature runs across the city of Lausanne and extends into Lake Geneva. Although fit is not observed on the southern shore of Lake Geneva probably because fit lies under a thick Quaternary cover, configuration of the AIpine units in this area suggests that the hult zone crosses the lake. To find out the location of the fault zone across the lake and to investigate its configuration, we acquired several high-resolution multi-channel seismic reflection profiles. The high quality of the seismic images obtained indicate that the fault zone includes a series of individual fault that can be accurately located.
-
-
-
Seismic characteristics of shallow fault zones
Authors V. Shtivelman and S. MarcoDetecting and mapping fault zones in the shallow subsurface is an important problem in various applications, such as engineering site characterization, seismic risk assessment, archeology and others. The commonly used method for this purpose is the high resolution reflection seismics.
-
-
-
Detecting fault of M = 7.6 Chi-Chi, Taiwan earthquake of 21 September 1999 using geophysical methods
By R. SunThe devastating M = 7.6 Chi-Chi, Taiwan Earthquake of 21 September 1999 caused about 2500 deaths and roughly US$12 billion in property loss. It is triggered by the rupture of the N-15°-E-striking, 120-km-long Chelongpu Fault, which is a direct result of the Philippine Sea Plate-Eurasia Plate collision, in central Taiwan.
-
-
-
Mapping karst features using a 2-D resistivity survey
Authors Z. Z. T. Harith and A. DevendranThe presence of pinnacles, and underground cave / cavern are common phenomena in limestone area. The occurrence of ground subsidence and sinkholes are always associated with this karsts area. The area of known existence of buried karsts topography should be considered as an unsafe or unstable area. In order to have a suitable design, details investigation of the subsurface is needed. Conventionally it is done using a closed spacing soil investigation (drilling) method, of which is very costly. An altemative investigation method proposed here is the Resistivity Imaging Technique. This is one of many types of geophysical investigation technique, which can be used to investigate the subsurface. On this site, it was proposed to use a 2-D Resistivity Imaging technique.
-
-
-
Optimizing the 2D laterally constrained inversion (2D-LCI) using a Quasi-Newton method and 1D derivatives
Authors A. V. Christiansen and E. Auken2D laterally constrained inversion (2D-LCI) is a new approach to interpretation of continuous resistivity data. The 2D-LCI enables a layered 2D inversion with sharp layer boundaries as compared to traditional smooth inversion types. However, the full 2D solution is quite time consuming when calculating the derivatives in the Jacobian matrix. To reduce the computation times we suggest using 1D derivatives, Broyden's update formula (Quasi- Newton) or combinations of Broyden's update formula and 1D derivatives together with the full 2D solution. The reduction in computation time is between 7 and 30 times dependent on the combination of approximations.
-
-
-
3D resistivity finite element modelling using mesh-independent electrode location
Authors L. Marescot, S. P. Lopes, S. Rigobert, R. Lagabrielle and D. ChapellierThe finite element method (FEM) has been used by several authors in the context of direct current (DC) forward modelling to calculate the response of surveys on complex earth structures (e.g. Coggon, 1971; Pridmore et al., 1981; Sasaki, 1994). In practice, geophysicists often wish to use the same electrode sequence for the simulation of different surveys.
-
-
-
Optimizing the information content of DC resistivity data
Authors H. Maurer, P. Stummer and A. G. GreenIn an attempt to exploit better the capabilities of multi-electrode acquisition systems, we have developed an experimental design procedure to identifi suites of electrode configurations that provide maximum subsurface information. The experimental design algorithm is based on a goodness function that ranks the sensitivity of every possible electrode configuration to changes in the subsurface parameters. To examine the potential and limitations of the new algorithm, we performed a synthetic experiment and compared the resolution power of the optimized data sets with those of Wenner and dipole-dipole configurations. The results indicate that the optimized configurations lead to substantially better inversion results than the standard data arrays.
-
-
-
Phase difference analysis for surface wave methods
Authors C. Strobbia and S. FotiSurface wave propagation can be analysed using a variety of signal processing techniques, most of which are based on spectral analysis. Transient data are decomposed into their monochromatic components: at each frequency the phase information can be used to compute the phase velocity, while the amplitude can be used to estimate the material attenuation. SW methods use the dispersive properties of Raleigh waves to infer the shear wave velocity profile at a site. Similarly the material attenuation can be used to estimate the dissipative properties of the deposit.
-
-
-
Study on surface wave resolution
Authors L. V. Socco and C. L. StrobbiaIn order to evaluate the effectiveness of a survey method and to supply information for survey planning it is very useful to estimate the spatial resolution related to investigation depth that can be achieved by the survey in different conditions.
-
-
-
Laterally consistent, correct elimination of the source signature in shallow, high-resolution seismic reflection surveys: possibility and benefits
By R. GhoseFor safe and efficient design and construction of structures, as well as for environmental and hydrogeological reasons, lateral variations in the shallow subsurface are important targets of investigation. A lack of knowledge of the lateral continuity or discontinuity of shallow soil layers or of lateral change in the physical nature of a layer has caused serious accidents in the past. Significant increase in the construction cost and unacceptable delays are also common. There are occasions when localized discontinuities in the clay cap layer have caused contamination of pure water at greater depths.
-
-
-
Non linear inversion of noise array measurements for determining S-wave velocity vertical profiles
Authors M. Wathelet, M. Ohrnberger, D. Jongmans, T. Camelbeeck and F. ScherbaumThe knowledge of the shear wave velocity (VS) profile at a given site is of major importance in earthquake engineering. The geophysical techniques generally used in soil dynamics to obtain shear wave velocity as a function of depth are the borehole tests (Jongmans, 1992), which are expensive and limited to shallow depths.
-
-
-
Wavefield composition and decomposition for the electro-kinetic reflection
Authors A. Ranada, E. Slob and C. P. A. WapenaarThe electro-kinetic effect represents a class of processes in which there is a conversion from electromagnetic to kinetic energy and vice versa. In the case of this transfer taking place in a saturated porous medium we name the effect electro-seismic for the transfer from electromagnetic to kinetic energy, and seismo-electric for the transfer from kinetic to electromagnetic energy.
-
-
-
Using a lattice solid model for vertical seismic profiles
Authors N. Fillipidou, S. Abe and G. G. DrijkoningenThe transmission of seismic energy through a sequence of layers consisting of unconsolidated material is by itself a challenging problem. The seismic pulse is known to broaden slightly with propagating distance, often described with a damping factor Q. In shallow sediments damping is very high compared to rocks, and should therefore show more pronounced effects of energy loss. One part of the losses can be described by viscoelastic losses, although viscosity is not the reality but is a way of giving a phenomenological description of damping. From a physical point of view, particles that can move in relation to each other seems to be more evident in unconsolidated or partly consolidated mediums like soils and other soft sedimentary formations.
-
-
-
Airborne geophysics for shallow object detection: Technology update 2003 - electromagnetics
Authors T. J. Gamey, W. E. Doll, L. P. Beard and D. T. BellORNL has been developing helicopter-mounted geophysical systems for detection of shallow buried objects since 1997. In collaboration with the U.S. Army Engineering Support Center - Huntsville and private sector partners we have focused our efforts on UXO detection and characterization, but the system is equally well adapted to any large area shallow mapping project such as utility locating, brownfield studies, hazardous waste sites and archeological sites.
-
-
-
Airborne geophysical surveys assessing the general scale quaternary mapping project in Finland
Authors E. Hyvönen, J. Lerssi and T. VäänänenGeological Survey of Finland has mapped surficial Quatemary deposits mainly at a scale 1:20000. These large scale maps cover only part of Finland. To fulfil the needs of the customers and the authorities a new mapping program begin in 2003 to produce maps and database at scale 1:250 000, covering whole Finland by the year 2007. The new database will contain geospatial distribution of sediment polygons and related attribute information. It will be produced by interpreting, modifying and generalising existing spatial data using GIS- and image processing techniques with minimum amount of field work (Nevalainen et al., 2002).
-
-
-
A detailed inversion scheme for helicopter-borne electromagnetic frequency-domain data
Authors R. J. Tølbøll and N. B. ChristensenGround-based electromagnetic methods have for many years successfully been employed for hydrogeological investigations in Denmark. A wish for higher efficiency has led to a growing interest in the possibility of using airborne electromagnetic methods in the mapping campaign, and lately the helicopterborne electromagnetic frequency-domain (HEM) method has been in focus.
-
-
-
SkyTEM - new development in high-resolution airborne TEM
Authors K. I. Sørensen and E. AukenIn Denmark, 99% of the water supply is based on groundwater abstraction. Increasing problems with the groundwater quality, due to urban growth and agricultural contamination, have caused the Danish Minister of Environment to approve a plan for improving ground water protection.
-
-
-
Ground penetrating radar modelling of rough underground interfaces
Authors A. Giannopoulos and N. DiamandiIn many electromagnetic scattering problems, the Earth's surface as well as subsurface interfaces are often modeled as planar dielectric boundaries (Cui and Chew, 1999). However, this assumption is not always valid and roughness in the Earth's subsurface can potentially be a major source of variability in the obsewed GPR signals. In some applications where shallow targets have constitutive properties very close to those of the background medium clutter due to the rough interface may introduce severe constraints on target localization and identification. As a result the detection of a buried object under a rough subsurface interface, using ground penetrating radar (GPR) could become problematic.
-
-
-
Mineral detection by a new approach to the compact inversion of gravity data
More LessA new approach for computing the regularization parameter in compact gravity inversion (Last and Kubik,1983) is presented. Neyman (1979) procedure for discrete data is used for the regularization parameter. A field example is demonstrated . Key words: Compact inversion, regularization parameter, mineral detection.
-
-
-
Polarization and acquisition in GPR surveys: tests on physical models
Authors P. Capizzi, P. L. Cosentino and L. RomanoIn most cases GPR surveys are carried out using co-pole data, because cross-pole data are generally not acquired. However, in the planning of GPR survey it is important to consider the antenna polarization, as the sensitivity of cross-pole and co-pole configurations is connected with the type of target as well as with the subsurface conditions.
-
-
-
Increase in measurement capacity of low frequency GPR investigations
By J. AaltonenTo carry out fieldwork with unshielded low frequency GPR systems with the aim to investigate groundwater and geological conditions requires today a comparable large work effort. This paper will show how using a new bistatic one-unit in-line antenna of 50 MHz can ease these types of investigations.
-
-
-
Test of the MRS technique in Southern Africa
Authors J. Roy and M. LubczynskiITC, together with ten collaborating agencies from seven countries is involved in a research project on the MRS (magnetic resonance sounding) technology since 1996, when IRIS Instruments introduced the NUMIS instrument. Thanks to regional collaboration, MRS tests were made in Botswana, Namibia and South Africa. The fieldtests were carried-out under a combination of low earth's magnetic field and high ambient noise conditions. The test sites included different aquifers from the point of view of lithology, depth and porosity thickness product. MRS field results and operational constraints are discussed.
-
-
-
On the inversion of complex magnetic resonance signals
By A. LegchenkoIt is known that the phase shift caused by electrically conductive subsurface makes the magnetic resonance signal complex (Legchenko, et al., 1990). Obviously, inversion of the complex signal may provide more information about the subsurface in comparison with inversion of only amplitudes currently available (Legchenko and Shushakov, 1998). Recently, an effort was made to improve the mathematical model used for interpreting MRS measurements.
-
-
-
Inversions of surface-NMR signals using complex kernels
Authors M. Braun and U. YaramanciSurface Nuclear Magnetic Resonance (SNMR) is used for groundwater exploration and aquifer characterization (e.g. [1]). The NMR-Experiment is conducted by a coincident transmitter and receiver loop at the surface exciting the protons of water molecules underground with the Larmor frequency of the earth's magnetic field. Performing a SNMR measurement with increasing excitation intensity (pulse moment) yields a complex sounding curve, where the amplitude of the relaxation signal is determined by the numbers of protons i.e. the water content. The subsurface electrical conductivity affects both the amplitude and especially the phase [2,3].
-
-
-
Correlation of remote sensing data and 2-D resistivity imaging method for evaluating paddy yields in Kedah, Malaysia - a preliminary study
Authors A. B. Saiful Bahari, M. S. Safid, M. N. M. Nawawi and K. AbdullahA preliminary study was conducted to investigate the feasibility of integrating remote sensing and 2-D resistivity imaging technique for evaluating paddy yield. The selected study site was a rice growing area in Kedah, Malaysia, developed by the Muda Agricultural Development Authority (MADA) as shown in Fig. 1(a).
-
-
-
Sampo - Frequency domain wide-band EM system for deep hydrogeological and environmental studies
Authors T. Valli, T. Jokinen, J. Lehtimäki and H. VanhalaSampo is a frequency domain wide-band electromagnetic (EM) sounding system constructed by Outokumpu co. and GTK. It consists of a magnetic dipole as a transmitter and a threecomponent receiver. The transmitter-receiver spacing (coil spacing) varies between 50 meters and 1500 meters, the latter being also the maximum depth of investigation.
-
-
-
Site conditions requiring extra precautions for induced polarisation measurements
More LessIn a precedent paper we compared sections acquired either with separated multicore cables and non-polarisable potential electrodes or with only one multicore cable and current and potential electrodes both in stainless steel. From the results obtained at two sites in Southern Sweden, we could conclude that it was possible to obtain good quality time-domain induced polarisation data with the simplified logistics. Consequently, we have applied the method to other sites, and could occasionally verify that it was justified. But in some cases, when the grounding resistances were very high, the quality of the induced polarisation data was very poor.
-
-
-
A 3D seismic survey applied to the study of an aquifer
Authors S. Picotti, G. Rossi and G. Böhm3D seismic survey is proven to be a very efficient tool for underground exploration, but up to now it has been used almost only for hydrocarbon production. In fact, the high costs of acquisition limited the use of this technology for other purposes, as for example hydrology applications. Today, however, the decreasing costs of equipment and the increasing water request are making this technology suitable in such a field too.
-
-
-
Geometrical description of an aquifer for the NAME project
Authors B. Ludovic and D. ChapellierThe NAME project (Nitrate from Aquifers and influence on carbon cycling in Marine Ecosystems) is a European research project which gathers hydro geologist, geophysicist, geochemist and marine biologist belonging to different institutions.
-
-
-
Resistivity surveying applied to hydrogeological characterisation of Quaternary paleo-valleys
Authors L. Marescot and D. ChapellierThe understanding of complex Quaternary structures has always been a major endeavour for geologists. Identifiing Quaternary paleo-valleys incised into the bedrock is important for understanding groundwater circulations and pollutants migration. Cost effective resistivity surveys may provide the fundamental information required by engineers for hydrogeologic modelling.
-
-
-
Deep layered structure investigation with multielectrode methods
Authors R. Hoffmann and P. DietrichDirect current geoelectrical measurements since several decades are used to investigate geological structures. With the rapid development of computer hard- and software and the advances made in the field of the measurment technology, multielectrode measurements have for many applications replaced the conventional four electrode equipment. 2D and 3D inversion software allows to invert large data sets. But, while lateral structures are usually well resolved, the interpretation of data sets over rather horizontally layered structures often fails-even falling back behind the achievements of a 1D investigation.
-
-
-
Geophysical assessment of groundwater protective layers
Authors R. Heinse and P. SchikowskyGroundwater protective layers covering the groundwater table play a crucial role in protecting groundwater from infiltrating contaminants. The protection depends heavily on the structure and texture of the groundwater covering layers. Sandy layers with low thickness will lead to a fast infiltration of contaminants whereas silty and clayey layers - because of their low hydraulic conductivity -have a higher protective potential.
-
-
-
Hydrogeological aspects of the helicopter borne electromagnetic measurements in the area between Cuxhaven and Bremerhaven, Lower-Saxony, Germany
More LessDuring the years 2000 and 2001 the area between Cuxhaven and Bremerhaven (Figure 1) was covered by high resolution helicopter borne EM (HEM) measurements (Eberle & Siemon 2002, Gabriel et al. 2003). In this area a complex coastal aquifer system comprising Quaternary sediments and deeply incised Pleistocene subglacial valleys is partly endangered by saltwater intrusions. In order to study the hydrogeology of the region in detail several geophysical and hydrogeological measurements are carried out including e.g. reflexion seismics, SIP-(spectral induced polarisation) and VES-(vertical electrical soundings) measurements, investigation drilling, hydrochemistry, and isotope hydrology (Kessels et al. 2000).
-
-
-
Mapping buried glaciofluvial aquifer by airborne EM measurements - A case from Kyrönjoki valley in Southern Finland
Authors H. Vanhala, I. Suppula, P. Lintinen and J. LehtimäkiMany buried valleys contain important groundwater reservoirs. Buried deposits discussed in this paper are glaciofluvial eskers and ice-marginal deposits wvered with lacustrine and glacilacustrine clays and silts.
-
-
-
Characterization of coarse materials using geophysical methods
Authors E. Rey, S. Garambois, D. Jongmans and P. GottelandThis summary deals with geoelectrical properties of coarse soils such as till deposits, rubbleslopes, alluvial fans or debris flow deposits. This type of soils is frequently found in the mountains areas. The presence of decimetric, sometime metric, blocks in these deposits makes them diacult to characterize using classical geotechnical in-situ tests. Being non-inhusive, geophysical measurements affect important volumes, are always possible anti rather rapid to execute. In addition the linear geometry of this type of measurements is interesting for locating lateral variations of the deposits, very frequent in this type of grounds.
-
-
-
Porosity and water saturation degree from combined resistivity and seismic surveys for geotechnical site characterization
Authors R. Mota and F. M. dos SantosPorosity and water saturation degree are some of the physical parameters that are commonly estimated in site characterization studies by laboratory tests in selected samples from geotechnical soundings. This kind of procedure gives discrete results, is time consuming and needs heavy equipment.
-
-
-
Groundwater exploration by use of TEM, reflection seismic surveys and drillings
Authors F. Jørgensen, E. Auken, H. Lykke-Andersen and K. I. SørensenThe Danish water supply is decentralized and based on private, public and municipal water works. Increasing problems with groundwater quality caused by pesticides and nitrate contamination have in recent years forced the county administrations to search for new deepseated and unpolluted aquifers in large parts of Denmark.
-
-
-
Re-establishment of the subterranean canals using VES data inversion
Authors M. Mirzaei and M. YousefiradFor solving hydrogeological and environmental tasks, geoelectrical methods are routinely applied. One of their advantages is their inexpensiveness while another advantage is the high resolution in near surface exploration problems.
-
-
-
Time-lapse azimuthal apparent resistivity measurements for estimating fracture dilatency on the coastal cliff top
Authors J. Busby, M. Raines, L. Nelder, P. Jackson and D. MorganThe erosion of hard rock cliffs is inevitable and to-date it has been considered to be relatively unpredictable. A large proportion of the European coastline is subject to erosion and cliff recession. This dynamic process continually changes the hydrogeological and stress regimes, exposes fresh geological features and materials to changes in environment and stress.
-
-
-
Identification of fracture zones by a travel time-based diffusivity approach
Authors R. Brauchler and P. DietrichRecently the irnportance of understanding fractured aquifers is increasing particular with the relevance to the question of water resources development, groundwater contamination and the search of suitable nuclear waste deposits. For the analysis of engineering, geotechnical and hydrogeological questions is the knowledge about the spatial position of fractures of particular irnportance. Conventional aquifer investigation methods like pumping or slug tests lead to integral information averaged over a large volume. This kind of information is insufficient to develop groundwater models requiring detailed information about the spatial distribution of fractures. To circumvent this problem new investigation methods have to be developed.
-
-
-
Near surface karst structure imaging for hydrogeological inverstigation with the VLF gradient method
Authors F. P. Bosch and I. MüllerConsidering the properties of carbonate rocks and the resulting demands for water management, we can formulate some requirements that geophysical methods applied to karst structure detection need to fulfil.
-
-
-
Seismic velocity anisotropy - measurement and application
Authors J. Dohnal, J. Hrdá, Z. Jáne, R. Prikryl, J. Vilhelm, T. Lokajícek, Z. Pros and K. KlímaTo find out water resources in crystalline rocks or to clean up contaminants in fractured bedrock, hydrologists must know the location of hydraulically conductive fracture zones. Some information about these zones is often obtained with single-borehole hydraulic tests, cross-borehole hydraulic tests, and tracer tests.
-
-
-
Water exploration on small Croatian islands by electrical tomography and refraction seismics
Authors F. Sumanovac, Z. Pekas and T. VlahovicWater explorations were carried out at three Croatian islands: Susak, which belongs to Kvarner islands, Dugi otok and Molat, which belong to northem Dalmatian islands. These explorations were carried out in a framework of a large hydrogeological project of water explorations at numerous Croatian islands.
-
-
-
Development of a new electric conductivity sensor in order to characterize soil solute concentration
Authors C. Frippiat, A. Renard and A. E. HoleymanLaboratory solute transport investigation can be performed using a large panel of tools. On one hand, Same techniques as in the field, including geophysical ones, can be used. However, these are bulk techniques which give an overall image of the soil heterogeneities and of the plume extension.
-
-
-
The description of underground water movement using ERT survey
Authors A. Bratus and D. N. YabarThis is a case history of a pilot test which has been performed in the NE of Italy to detect and monitor the sub-surface behaviour of a salt-water solution within a sand-gravel aquifer. ERT (Earth Resistivity Tomography) was used. The experiment consisted in pumping a of saltwater solution - which presents a low resistivity value - into a well, in order to detect variations of resistivity vs. time during the flow of the solution within the aquifer.
-
-
-
Actual possibilities concerning the determination of groundwater flow with single well methods
Authors T. Feischl and F. KerschnerIn many hydrogeologic applications the determination and monitoring of groundwater flow parameters, especially groundwater seepage velocity and groundwater flow direction are an essential part regarding analyze of groundwater flow. This includes questions like water supply location, ground water plume characterization inter alia for contamination issues, landfill leachate characterization, inflow and outflow analysis, hazardous spill response and also environmental surrounding effects like tidal effects on groundwater aquifers. This paper gives an insight about the advantages and disadvantages of the traditional Multi-Well methods and the less time consuming but sometimes adulterated Single-Well methods. Further on another Single-Well method the Dark-Field-Sonde is introduced. Including field and laboratory tests of this tool in comparison to other methods during a benchmark test gives an impression about the reliability, and possibility of actual groundwater flow measurement.
-
-
-
Interurban - geophysical assessment of water dynamics and solute transport in urban soils
Authors M. Müller, O. Mohnke, J. Schmalholz and U. YaramanciUrban soils are subject to strong variations of environmental conditions, like water flow, solute transport or heat budget. The research project INTERURBAN has been formed to study the dynamics of water and materials at urban locations with special consideration of the spatial heterogeneity, the organic soil substance and soil-biological transformation processes. The objectives of the research group define the target for geophysics: The development of a noninvasive conception to map the water distribution and important structural parameters with high resolution. In addition to standard methods, like Geoelectrics and Ground Penetrating Radar (GPR), Spectral Induced Polarization (SIP) also Surface Nuclear Magnetic Resonance (SNMR) will be used. We have choosen two locations typical for urban soils: The Tiergarten (Berlin, Germany), a metropolitan park with intensive use by pedestrians, sportsmen and big events (Love Parade) and a former sewage farm in Buch at the outskirts of Berlin. The soil in Buch is highly contaminated by organic hydrocarbons and heavy metals. In this paper we show examples of the necessary methodological improvements for the application of high resolution shallow geophysics for high resolution assessment (see Muller et al., 2002).
-
-
-
Long-time monitoring of soil water content and apparent resistivity
By P. NovákThe apparent resistivity of soil is one of the most important parameters of shallow geoelectrical survey. Soil resistivity varies a lot in time and space. Soil resistivity depends on resistivity of soil framework, structure and volume of pore space and soil water content and mineralization.
-
-
-
Mathematical model of land subsidence above fluid-carrying reservoir adjacent to clay layer
Authors A. V. Kosterin and M. M. ToropovaIt has been known that fluid withdrawal from an underground reservoir adjacent from below to a water saturated clay layer can cause land subsidence running up several meters and extending over a considerable area [1 - 3]. The reservoir's decompression due to fluid withdrawal is accompanied by clay layer's compaction under the influence of rock mass weight and as a result water outflow from it into the reservoir. So, land subsidence in this case is governed mainly by clay layer compaction. In the present paper a mathematica] model of such process is proposed. Analytical expressions for pressure distribution, water outflow from clay layer into the reservoir and land subsidence were obtained. These expressions make it possible to analyze the change of their development rate. The connection between maximum subsidence and rheological parameters of clay layer were found in analytical form.
-
-
-
Joint application of high-resolution seismic and GPR measurements to monitor sludge deposition: Advances of the geowaters project
Authors T. Tóth, H. de Boom, B. James, I. Lemperger, S. Puszta, D. van der Roest, G. Sideris, G. Tsokas, K. Vrana and V. ZolotarevNew sediment layers accumulating on the floors of rivers, canals, lakes, and harbours in industrialised countries contain varying amounts of contarninants, which have been discharged from a range of activities, both legal and illegal. These contaminated sediments are known collectively as sludge and have been accumulating for decades. The identification of contamination in waterways has led to the realisation that there is a need to carry out surveys of the pollution, in many cases followed by remediation. Contaminated water floors, though probably created in the past, continue to disperse their pollutants in the water, thus creating a potential effect on the quality of drinking water and recreational water. Remediation work can only be carried out in a cost effective way if it is preceded by a site survey, which provides high resolution data. 95% of current site surveys are done by collecting hand drilled cores for examination and analysis. These point sources of data are then used to try to give an impression of the sludge layers, but the resolution is extremely poor. Contamination may be found, but the volumes cannot be exactly quantified.
-
-
-
Two-dimensional geoelectrical imaging across a septic tank
More LessThe septic tank system is one of the most common, cheapest and most suitable means of sewage disposal in developing countries. The tank is constructed to store faeces and other solid materials, while the excess water is displaced into a seepage or soakaway pit. The soakaway pit is designed to permit the effluents to seep into the surrounding soil readily. In this paper, the use of numerical modellig and inversion of apparent resistivity data to simulate the environmental imapct of a septic tank (and the effluents emanating from it) on the environment is reported.
-
-
-
Multi-receiver OhmMapper survey over a former fuel tank site
Authors L. Pellerin, D. Groom and J. JohnstonGeoelectric data were acquired with the OhmMapper TR4 (OM-TR4) at the Camp Parks Reserve Forces Training Area (RFTA) former tank farm to map the near subsurface resistivity and possible association with a 30 to 40 year old hydrocarbon plume and locate any additional pipelines and subsurface infrastructure
-
-
-
A comparative study of different electric imaging configurations in investigation of a fresh-saline groundwater interface
By P. H. GiaoElectric imaging (EI) can be useful in solving various geotechnical-geoenvironmental problems. In this study, EI was applied to investigate a salinized soil ground in the NE Thailand for locating the interface between saline and fresh groundwater due to brine water pumping activity for salt production in the area. A manual electric imaging procedure was applied instead of using an automatic electric imaging with multi-cable and multi-electrode system. To enhance efficiency and production of the manual EI procedure, a comparative study was made on various configurations, i.e., dipole-dipole, pole-dipole, Wenner and Schlumberger. All of the arrays worked very well, but the Wemer configuration gave the best electric response with reference to a vertical interface of resistivity contrast, while the poledipole has the largest depth of investigation.
-
-
-
Vertical radar profile monitoring of the vadose zone dynamics and oscillating water table
Authors G. Cassiani, L. Gallotti, V. Ventura and G. AndreottiThe identification of flow and transport characteristics in the vadose zone is a fundamental step towards understanding the dynamics of contaminated sites and the resulting risk of groundwater pollution.
-
-
-
Geoelectrical investigations of a kerosene contaminated site at the Schwerin-Parchim airport
Authors M. Grinat, J. Sauer and W. SüdekumDuring the last years many publications dealt with geophysical methods aimed at locating and characterizing light non-aqueous phase liquids (LNAPL) in the subsurface showing the increasing relevante of this kind of contamination (e.g. ATEKWANA et al. 2000; ORLANDO 2002; SAUCK 2000).
-
-
-
Comparison of different 3D geoelectric survey layouts for detection of saltwater convection cells in the Okavango Delta (Botswana) and determination of 3D effects in 2D surveys
Authors R. Supper, P. Bauer, W. Kinzelbach and S. ZimmermannThe Okavango Delta is a huge wetland ecosystem in northwestern Botswana, Southern Africa. Water from the moist tropical highlands of southern Angola flows down the Okavango river, spills into the Kalahari basin and forms an alluvial fan of the size of approximately 30 000 km2. Some 6000 km2 of permanent swamps form the core of the Delta and towards the fringes, the environment is gradually becoming drier. In this continuum h m wet to dry environments, a rich variety of flora and fauna has developed.
-
-
-
Environmental radioactivity of natural and man-made sources in the Czech Republic
By M. MatolinNatural sources imply cosmic radiation, terrestrial radiation and natural radionuclides in water and air. Natural sources of radiation may be also concentrated in the environment by human activities. Examples of these are uranium mining, transport and deposition of U-ores and barren rock, uranium processing, coal mining, and the use of phospate and potassium fertilizers in agriculture. The use of man-made radioisotopes in industry, nuclear power plants and various man activities may result in their escape, transfer and deposition as nuclear fallout. Geophysical radiometric methods have the capacity of location, monitoring and assayss of these various bulk radiation sources in the environment and enable estimates of their radioactivity levels and their assessment.
-
-
-
Integrated non-invasive characterization of waste disposal sites
Authors G. Dal Moro, M. Pipan, E. Forte, M. Sugan and I. FinettiNon-invasive characterization of waste disposal and contaminated sites provides large amounts of subsurface information at low cost and is a highly desirable approach for site management.
-
-
-
Investigation of a waste landfill using electrical resistivity and induced polarisation tomography
Authors G. De Bacco, A. Godio and L. SambuelliElectrical Resistivity Tomography (ERT) and Induced Polarisation Tomography (IPT) were performed to investigate a municipal waste landfill located in the North of Italy. The object of the study is the oldest parcel of the landfill, where the waste disposal started in the early 70's and finished more than 20 years ago.
-
-
-
Enlargement of cone penetration testing equipment with resistivity measurements: field measurements, case histories
Authors P. Draskovits, I. Fejes, B. Magyar and J. StickelIn former papers (Fejes, Jósa, 1990; Draskovits, Fejes, Magyar, Stickel, 1999 and 2000), measurement and geological-petrophysical interpretation of mechanical and nuclear parameters obtained with the help of the own-developped CPT equipment were introduced. In the present paper the possibility for measuring a following parameter, the resistivity will be shown.
-
-
-
Well logging for checking the quality of reservoir dams and sealing walls
By M. ProcházkaThe spectrum of well logging activity expands from year to year and well logging is now used in a range of fields, where it was previously unknown. Significant improvement in quality was noted for well logging in the field of geological engineering and in the sphere of construction activity. With the use of modem techniques, new methods were developed and several of these methods are patented and only provided by our company.
-
-
-
Borehole radar performance on fracture zone characterisation in crystalline bedrock
Authors E. Heikkinen, P. Saksa, T. Lehtimäki and P. HelläBorehole radar is, together with reflection seismic investigations one of scarce available methods for investigating the bedrock properties at further range than immediate borehole surroundings. In crystalline bedrock characterization project for disposal of the spent nuclear hel, the borehole radar measurements have been used mainly for investigation of orientation of the fracture zones and their extent from the borehole. Detailed and reliable information is required in this task. Radar method is relatively fast to be implemented and interpreted. Fractures and fracture zones, and their location, orientation, continuity and properties have been attempted to be assessed from the results. The bedrock properties that relate to radar reflections were assessed in detail by comparing reflections to other available borehole data. Comparison of data sets from different scales of observation has not been always a straightfonvard task. Better understanding of the radar method will allow more efficient use of the results.
-
-
-
An approach to the electrical tomography aimed to the investigation of particular confined structures
Authors P. L. Cosentino, R. Martorana and V. SanfratelloIn this paper we present a practical approach to the electrical tomography when applied to materials having particular shapes (like the columns). Simple cylindrical shapes have been tested, and the general model has been selected as a set of elements having circular sections of some angle and thickness.
-
-
-
Geophysical techniques for maritime archaeological surveys
Authors M. Lawrence, I. Oxley and R. BatesOver the last 10 years, the high-resolution marine geophysical survey field has witnessed significant advances in survey investigation equipment. New equipment is based on acoustic, optical, electrical and magnetic sensors however this paper will focus on the use of quantitative acoustic methods for the high resolution mapping of the seafloor for archaeological heritage management.
-
-
-
3-D inversion of VES data from, Saqqara archaeological area, Egypt
Authors G. El-Qady, F. A. Monteiro Santos, A. Gh. Hassaneen and L. TrindadeSaqqara is one of the most important archaeological sites in Egypt. It is characterized by some of the oldest pyramids on the earth, ancient temples and a vast area of hidden archaeological remains.
-
-
-
Diproved techniques of the micro-seismic tomography with S-waves for the non-destructuve testing on masonry structures
Authors M. Marchisio, L. D'Onofrio, A. De Falco, L. Frediani and F. GuidoniThe Geophysical Section of the Dipartimento di Ingegneria Civile of the University of Pisa has been active in researches on the application of non-pervasive geophysical surveys on the masonry structures of historical buildings for more than ten years.
-
-
-
Laboratory determination of electric properties of ornamental stones in georadar high frequency band
Authors L. Sambuelli, P. Marini, R. Tascone, D. Vaccaneo and F. BrattaA new measurement system of dielectric permittivity and loss tangent of ornamental stones used for example on historical buildmgs has been developed Complex permittivity has been measured in the frequency range 1.1 - 1.7 GHz on samples chosen between marbles, sandstones and limestones. The values of dielectric parameters were measured experimentally by placing the sample in a resonant cavity obtained from a waveguide. The research has been developed to define a laboratoy testing method in order to improve GPR interpretation by creating a data base of electromagnetic properties of the analysed materials.
-