Studies on Multiplication of the Depth of Detectability Using y 11n Arrays | Chapter 8 | International Research in Environment, Geography and Earth Science Vol. 6

 A basic parameter of all geophysical methods, including geoelectrics, is the depth of investigation (DI). A critical parameter in geophysical exploration has always been the depth from which knowledge can be accessed. This paper deals with the detectability depth (DD) of configurations of 2D electric resistivity tomography. In the presence of a given noise level, DD is the maximum depth from which a given model body is observable. This paper shows that there is a nearly linear relationship between the maximum value of their parameter-sensitivity (PS) maps and their DD values, based on previous DD measurements for traditional electrode arrays. We found that many of them have higher PSmax values than those of traditional arrays when analysing the PS maps of other arrays, as well. Therefore, these so-called γ arrays are supposed to also have larger DD values. This expectation has been verified by the executed DD calculations. Linear geoelectric arrays, where γ refers to the CPCP, are γ arrays Arrays have consistently generated higher DD values than the best traditional arrays if n is greater or equal to 2. The DD value of these arrays can be 2-3 times greater than the best value of the conventional array. Such an improvement in the DD value is particularly useful when the measurement space available is reduced, e.g. due to infrastructural conditions. Large-depth anomalies, for example, that are not seen by traditionally used arrays, can be detectable using γ-arrays, as numerical studies have also verified. In addition, these arrays require less measurement than most conventional arrays, which results in shorter measurement time. According to the above observations, the γ ⁇ arrays and particularly the γ ⁇ -, γ ⁇ - and γ ⁇ arrays can be a useful alternative to traditional arrays, especially in sites where the place available for measurements is limited (e.g. built-up areas), because they can provide information from greater depths. Measurements are mor with these arrays more Consuming less time

Author (s) Details

Sándor Szalai
CSFK GGI, H-9401 Sopron POB 5, Hungary and Department of Geophysics, University of Miskolc, H-3515 Miskolc-Egyetemváros, Hungary.

Dr. Mátyás Krisztián Baracza
Research Institute of Applied Earth Sciences, University of Miskolc, H-3515 Miskolc-Egyetemváros, Hungary.

István Lemperger
CSFK GGI, H-9401 Sopron POB 5, Hungary.

Mohamed Metwaly
Archaeology Department, College of Tourism and Archaeology, King Saud University, Saudi Arabia and National Research Institute of Astronomy and Geophysics (NRIAG), Cairo, Egypt.

Árpád Kis
CSFK GGI, H-9401 Sopron POB 5, Hungary.

Attila Novák
CSFK GGI, H-9401 Sopron POB 5, Hungary.

View Book :- https://bp.bookpi.org/index.php/bpi/catalog/book/283

Which Geoelectric Array Sees the Deepest in Noisy Environment? Depth of Detectability Values of Multielectrode Systems over Various TwoDimensional Models | Chapter 9 | International Research in Environment, Geography and Earth Science Vol. 6

 

The two dominating difficulties of any geophysical measurement in the urban setting are as follows : ( 1) the area available for measurement is small, so the geoelectric layout length is also small; (2) the noise level is high, and the noise reduces the maximum depth from which any subsurface target can be detected. From the results of two-dimensional numerical model computations assuming multielectrode (electrical resistivity tomography) measurements, we determined the depth of detectability values ( i.e. maximum depth values at which still useful information about a given inhomogeneity is obtained at a given noise level). We conducted detectability studies in detail for six different geoelectric arrays, assuming different noise levels. The depth of detectability is both array-and model-dependent, as it has been found. Therefore, it is recommended to pick an array in a field study that has the greatest possible depth of detectability values for the given model. At the noise level given. If there is no a priori assumption about the subsurface model, we suggest either the pole-dipole (P-DP) array or the dipole axial (DP-ax) array as a default option, because they have the largest detectability values for most models we have studied. A double increase in the level of noise can lead to a decrease of approximately two in the detectability depth itself.

Author (s) Details

Sándor Szalai
1CSFK GGI, H-9401 Sopron POB 5, Hungary and Department of Geophysics, University of Miskolc, H-3515 MiskolcEgyetemváros, Hungary.

Mátyás Krisztián Baracza
3Research Institute of Applied Earth Sciences, University of Miskolc, H-3515 Miskolc-Egyetemváros, Hungary.

Attila Novák
CSFK GGI, H-9401 Sopron POB 5, Hungary.

László Szarka
CSFK GGI, H-9401 Sopron POB 5, Hungary.

View Book :- https://bp.bookpi.org/index.php/bpi/catalog/book/283

Studies on Multiplication of the Depth of Detectability Using y 11n Arrays | Chapter 8 | International Research in Environment, Geography and Earth Science Vol. 6

 

A basic parameter of all geophysical methods, including geoelectrics, is the depth of investigation (DI). A critical parameter in geophysical exploration has always been the depth from which knowledge can be accessed. This paper deals with the detectability depth (DD) of configurations of 2D electric resistivity tomography. In the presence of a given noise level, DD is the maximum depth from which a given model body is observable. This paper shows that there is a nearly linear relationship between the maximum value of their parameter-sensitivity (PS) maps and their DD values, based on previous DD measurements for traditional electrode arrays. We found that many of them have higher PSmax values than those of traditional arrays when analysing the PS maps of other arrays, as well. Therefore, these so-called γ arrays are supposed to also have larger DD values. This expectation has been verified by the executed DD calculations. Linear geoelectric arrays, where γ refers to the CPCP, are γ arrays Arrays have consistently generated higher DD values than the best traditional arrays if n is greater or equal to 2. The DD value of these arrays can be 2-3 times greater than the best value of the conventional array. Such an improvement in the DD value is particularly useful when the measurement space available is reduced, e.g. due to infrastructural conditions. Large-depth anomalies, for example, that are not seen by traditionally used arrays, can be detectable using γ-arrays, as numerical studies have also verified. In addition, these arrays require less measurement than most conventional arrays, which results in shorter measurement time. According to the above observations, the γ ⁇ arrays and particularly the γ ⁇ -, γ ⁇ - and γ ⁇ arrays can be a useful alternative to traditional arrays, especially in sites where the place available for measurements is limited (e.g. built-up areas), because they can provide information from greater depths. Measurements are mor with these arrays more Consuming less time

Author (s) Details

Sándor Szalai
CSFK GGI, H-9401 Sopron POB 5, Hungary and Department of Geophysics, University of Miskolc, H-3515 Miskolc-Egyetemváros, Hungary.

Dr. Mátyás Krisztián Baracza
Research Institute of Applied Earth Sciences, University of Miskolc, H-3515 Miskolc-Egyetemváros, Hungary.

István Lemperger
CSFK GGI, H-9401 Sopron POB 5, Hungary.

Mohamed Metwaly
Archaeology Department, College of Tourism and Archaeology, King Saud University, Saudi Arabia and National Research Institute of Astronomy and Geophysics (NRIAG), Cairo, Egypt.

Árpád Kis
CSFK GGI, H-9401 Sopron POB 5, Hungary.

Attila Novák
CSFK GGI, H-9401 Sopron POB 5, Hungary.

View Book :- https://bp.bookpi.org/index.php/bpi/catalog/book/283