About Demo Version The GPR data

(1)

______________________________________________________________________

gpr-soft.com [email protected]

GEORADAR- EXPERT

Software System for Automated Processing of GPR Data

About Demo Version

(2)

______________________________________________________________________

About Demo

In the demo version of the GEORADAR-EXPERT software system, the GPR data files and 3D assembly are built into the executable file. To open a data file, you need to select the name of this file from the list in the File menu and left-click on the menu bar containing this name.

By default, the demo version includes five GPR profiles PR95, FILE216, PR0074, Tankovy_proezd, FILE52 and one three-dimensional assembly of sections of the Q-factor attribute 3D Assembly. Below will be an overview of each demo data file.

The GPR data for the demo version was taken from previously performed GPR research projects and was selected taking into account the fact that the application of traditional methods of digital signal processing to these data did not lead to positive results. However, the use of the results of an automated analysis of the back-scattering electromagnetic field (BSEF) in the form of sections of wave field attributes and subsurface medium parameter attributes, which were created in GEORADAR-EXPERT, made it possible to successfully solve the problems of GPR research.

The demo distribution package includes parameters files for creating sections, whose names consist of the names of the corresponding GPR profiles of the demo version and the names of the section attribute.

Section creation parameter files have the geprm extension:

(3)

______________________________________________________________________

Files of parameters for creating sections allow the user to understand the settings of the GEORADAR- EXPERT software system at the initial stage of familiarization with the demo version. These files are loaded into the program using the Load Settings menu located in the Section menu group:

Also using the Load settings button located on the Section panel:

After completion of the process of loading parameters for creating a section, the Section tab opens with a placeholder for the section that is yet to be created, and an information panel containing a message

(4)

______________________________________________________________________

that the parameters are loaded, but in order to start the process of creating a section, the user needs to perform certain actions:

To start the process of creating a section, close the information panel by clicking on this panel with the mouse and click the Section button on the Section panel, or use the Create Section menu from the Section menu group. After completion of the section creation process, an information panel will appear with a message about this:

(5)

______________________________________________________________________

Important! When the section has already been created and the user has loaded the section creation settings file with other settings, it is necessary to start the section creation process again. The fact is that most parameters are applied at the stage of calculating the section and only the settings for visualizing the section contained in the Filled Contour Plot and Settings of Colormap for Section panels are applied to the section that has already been created or during the creation of the section at the final stage.

The demo version is an analogue of the full-featured version of the GEORADAR-EXPERT software system, with the exception of the ability to load and process third-party GPR data files. It is possible to test the GEORADAR-EXPERT software system on your own data. To do this, send GPR profiling data files to the technical support email address provided in the <Useful Links> chapter. These files will be added to the demo version.

The number of user files should be no more than three, the length of each GPR profile should not exceed 100 m for GPR with a central frequency of 500 MHz and lower, and no more than 25 meters for GPR from 500 MHz and higher. For each GPR profile, it is necessary to provide brief information about the purpose of the GPR survey, during which the data were obtained, characterize the weather conditions during the GPR survey (for example, dry, wet, frosty) and the description of the GPR survey place (for example, field, forest, city).

For the correct result of the automated analysis of the back-scattering electromagnetic field (BSEF), GPR profiles must satisfy certain conditions. You will find these conditions in the user manual for the GEORADAR-EXPERT software system, in the Automated Analysis BSEF section, the chapter Parameters of the GPR Profiling. The user manual can be downloaded from the link provided in the <Useful Links>

chapter of this description.

Other methods for processing GPR data implemented in the GEORADAR-EXPERT software system do not require any conditions for the parameters of the processed GPR profiles.

(6)

______________________________________________________________________

List of GPR Data Included in the Demo Version by Default

LINE 968

The LINE 968 GPR profile was obtained during the study of bulk soil with a GPR with a central frequency of probe pulses of 200 MHz. The studied bulk soil has a strong absorption of electromagnetic pulses, because of which the amplitudes of reflections from the bottom of the bulk soil are lower than the level of noise and interference. For this reason, the boundary between bulk and bedrock in the raw GPR profile is not visible:

The use of standard digital signal processing methods for the GPR profile to suppress noise and detect GPR signals reflected from the bottom of the bulk soil did not lead to a positive result. The figure below shows the result of such processing - as a result of frequency filtering and average subtraction, the interference is suppressed, but the reflections from the bottom of the bulk soil are still not visible:

The figure below shows the section of the attribute Re(permittivity) - the real part of the complex relative permittivity, the creation settings of which are contained in the LINE 968 Re(permittivity).geprm file.

(7)

______________________________________________________________________

The section can be divided into two layers, where the top layer is bulk soil. In the section, loose soil corresponds to colors ranging from yellow to dark red. The bedrock is represented by colors ranging from green to blue. Looking at the changes in the color gamut of the section, you can see the changes in the electro physical characteristics of the soil inside each layer.

The figure below shows the section of the attribute Weight water content, the creation settings of which are contained in the file LINE 968 Weight water content.geprm.

(8)

______________________________________________________________________

To indirectly estimate the relative density of the soil, you can use the attribute Q-factor (the ratio of the center frequency to the width of the spectrum of the reflected signals). The figure below shows the section of the Q-factor attribute, the creation settings of which are contained in the LINE 968 Q- factor.geprm file. On the section, the least dense soil is displayed in red; the relatively dense soil is shown in blue. Moreover, the darker the blue color, the denser the soil:

(9)

______________________________________________________________________

PR95

The PR95 profile was obtained using a GPR with a center frequency of 250 MHz probing pulses. The GPR profile crosses the bed of a dry stream, the middle of the channel corresponds to an elevation of 25 m from the beginning of the profile. The middle of the creek corresponds approximately to the mark of 25 meters from the beginning of the profile:

The electro physical characteristics of the studied soil change smoothly, without sharp transitions, from which the probing GPR pulses could be reflected. For this reason, the GPR profile does not have characteristic in-phase signals, which can be interpreted as reflections from the boundaries of the layers.

Under these conditions, it is impossible to obtain information on the structure of the section without the use of the automated analysis of the backscattering field BSEF, implemented in the GEORADAR-EXPERT software system.

The parameters file PR95 Weight water content.geprm contains settings for creating a section of the Weight water content attribute. The figure below shows the result of creating a section:

(10)

______________________________________________________________________

The section shows that the areas of the highest moisture content are located in the middle of the channel in the depth range from 2.5 to 3.5 meters, and the boundary between dense soil and loose sediments has a concave shape and reaches a depth of just over 7 meters at a distance of 27.5 meters from the beginning of the GPR profile.

(11)

______________________________________________________________________

FILE216

The GPR profile FILE216 was obtained in the permafrost zone in summer using a GPR with a central frequency of 200 MHz.

The FILE216 Re (permittivity) .geprm parameter file contains settings for creating a section of the Re (permittivity) attribute - the real part of the complex relative permittivity. The figure below shows the result of creating a section. In the upper part of the section there is a layer of seasonal thawing, which has a green-yellow-red color scheme. Below are the soils in the frozen state, on the section these soils have blue shades:

(12)

______________________________________________________________________

Because the permittivity of water is higher than that of rock-forming minerals, soils with increased values of permittivity are characterized by increased humidity. The wettest area of the section, which has the highest permittivity, is colored dark red and is located between 30 and 40 meters along the profile. The maximum depth of this area reaches 1.4 meters.

Without the use of an automated backscatter field analysis BSEF, it would be difficult to obtain information on changes in the electro physical characteristics of the seasonal thawing layer.

PR0074

Profile PR0074 obtained by GPR with a central frequency of probing pulses of 1700 MHz. The profile was obtained during the GPR survey of a monolithic reinforced concrete slab 0.25 meters thick lying on the ground:

(13)

______________________________________________________________________

The file PR0074 Re(permittivity).geprm contains the settings for creating a section of the attribute Re(permittivity) - the real part of the complex relative permittivity. The figure below shows the result of creating a section in the form of a contour plot with a data step of 0.1 units:

The change in the values of the permittivity in the thickness of the concrete slab is related to the humidity of the concrete - the greater the dielectric constant, the higher the humidity. In turn, the degree of

(14)

______________________________________________________________________

moisture is associated with the strength of the material - high humidity corresponds to areas of reduced strength, which are characterized by the presence of microcracks and pores filled with moisture.

The PR0074 Concrete moisture content.geprm file contains settings for creating a moisture section of concrete - see the figure below. In the color map of the section, drier areas are shown in red. The section shows that the driest, and therefore the strongest, areas of concrete are located closer to the center of the slab thickness. The areas adjacent to the surface of the slab from above and below have a higher dielectric constant than in the central zone. This is due to the impact of atmospheric precipitation from above and groundwater from below on the surface of the slab.

The file PR0074 Concrete conductivity.geprm contains settings for creating a section of concrete conductivity - see the figure below. Increased conductivity values are shown in blue. Areas of increased conductivity correspond to the position of areas of increased humidity in the Concrete moisture content section.

(15)

______________________________________________________________________

Concrete moisture and conductivity sections are calculated using the formulas published in the article [Jin X, Ali M. Simple empirical formulas to estimate the dielectric constant and conductivity of concrete.

Mierow Opt Technol Lett. 2019; 61: 386-390.]. These formulas are only valid for concrete. For this reason, for the underlying soil, starting from a depth of 0.25 meters, the values on the moisture and conductivity sections can be considered incorrect.

(16)

______________________________________________________________________

Tankovy_proezd

The Tankovy_proezd profile was obtained by GPR with a central frequency of probing pulses of 150 MHz.

First, GPR moves on the asphalt concrete pavement of the city roadway, and after 30 m - along wet loam:

The file Tankovy_proezd Re(permittivity).geprm contains the settings for creating a section of the attribute Re(permittivity) - the real part of the complex relative permittivity. The figure below shows the result of creating a section with a translucent overlay on the GPR profile:

In the section, a layer of wet loam is displayed in blue.

(17)

______________________________________________________________________

FILE52

The FILE52 profile was obtained in winter on permafrost soils under urban conditions. The purpose of the GPR study is to identify thawing zones due to a violation of the tightness of the septic tank located in the thickness of permafrost.

The penetration of warm wastewater outside the septic tank causes the thawing of permafrost, which threatens the integrity of the foundations of nearby buildings. The figure below shows the location plan of the GPR profile (blue arrow) and a photo of the accident site:

(18)

______________________________________________________________________

The FILE52 Re (permittivity) .geprm parameter file contains settings for creating a section of the Re (permittivity) attribute - the real part of the complex relative permittivity. The figure below shows the result of creating a section. In the section, frozen soil is displayed in blue shades. The thawed soil is represented by a yellow-red color scheme, and the wetter the soil, the more intense the red color. Most humidification occurs at the location of the septic tank (27 meters from the beginning of the GPR profile), the thawing depth is more than 3 meters:

(19)

______________________________________________________________________

3D assembly

A three-dimensional assembly of sections of the Q-factor attribute was obtained based on the results of a GPR study of the site for the construction of an oil and gas complex in Eastern Siberia. The studies were performed by GPR with a central frequency of probing pulses of 50 MHz. On the study site, zones of loose soils were found, which are displayed in red on the 3D assembly:

The figures below show a 3D assembly with isosurfaces passing through the values of the Q-factor 3.5, 3.8 and 4, which correspond to the most loose soil sections:

(20)

______________________________________________________________________

Useful Links

The GEORADAR-EXPERT web site:

https://gpr-soft.com/

The GEORADAR-EXPERT user manual:

https://gpr-soft.com/download/georadar_expert_manual_eng.pdf

Watch or download video tutorials:

https://gpr-soft.com/Video.html

Information brochures:

https://gpr-soft.com/download/ge_software_review_eng.pdf https://gpr-soft.com/download/ge_brochure_eng.pdf

Technical support:

[email protected]

(21)

______________________________________________________________________