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Impact of Data Processing and Antenna Frequency on Spatial Structure Modelling of GPR Data.

De Benedetto D, Quarto R, Castrignanò A, Palumbo DA - Sensors (Basel) (2015)

Bottom Line: The results showed that the type and range of spatial structures of GPR data did not depend on data processing at a given frequency.It was also evident that the noise tended to decrease with the complexity of processing, then the most error-effective procedure was selected.The results highlight the critical importance of the antenna frequency and of the spatial scale of soil/subsoil processes being investigated.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Scienze della Terra e Geoambientali, University of Bari, Aldo Moro, Bari 70125, Italy. daniela.debenedetto@entecra.it.

ABSTRACT
Over the last few years high-resolution geophysical techniques, in particular ground-penetrating radar (GPR), have been used in agricultural applications for assessing soil water content variation in a non-invasive way. However, the wide use of GPR is greatly limited by the data processing complexity. In this paper, a quantitative analysis of GPR data is proposed. The data were collected with 250, 600 and 1600 MHz antennas in a gravelly soil located in south-eastern Italy. The objectives were: (1) to investigate the impact of data processing on radar signals; (2) to select a quick, efficient and error-effective data processing for detecting subsurface features; (3) to examine the response of GPR as a function of operating frequency, by using statistical and geostatistical techniques. Six data processing sequences with an increasing level of complexity were applied. The results showed that the type and range of spatial structures of GPR data did not depend on data processing at a given frequency. It was also evident that the noise tended to decrease with the complexity of processing, then the most error-effective procedure was selected. The results highlight the critical importance of the antenna frequency and of the spatial scale of soil/subsoil processes being investigated.

No MeSH data available.


Graph of correlation matrix for GPR data acquired with 250 MHz antenna and processed with third processing procedure (time zero correction, dewow filter, bandpass filter and envelope). Person’s correlations (r) are reported and all coefficients are significant at 0.05 probability level.
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sensors-15-16430-f005: Graph of correlation matrix for GPR data acquired with 250 MHz antenna and processed with third processing procedure (time zero correction, dewow filter, bandpass filter and envelope). Person’s correlations (r) are reported and all coefficients are significant at 0.05 probability level.

Mentions: Statistical analysis highlighted that GPR data at any frequency and for all procedures showed clear departure from normal distribution, however the addition of further steps in the processing (after the third procedure) caused a more symmetric distribution. In addition, Person’s correlations allowed you to disclose the main reflections observed visually in the radar sections and to evaluate the strength of spatial association between the data at the different depths as function of the processing procedure. The GPR amplitudes at the different times were strongly correlated within an interval of 10–14 ns, for 250 MHz antenna (mainly evident in the data processed with the third procedure, as reported in Figure 5). This time interval may be related to the “second” reflection, which was not detectable visually in the radar sections but only in CMP data. The correlation coefficient showed a discontinuity in the range 10–12 ns for the 600 MHz antenna at the corresponding depth range of 0.3–0.36 m, not evident in the radar sections, which may be due to agricultural tillage. On the contrary, the correlations between the time slices corresponding to the 1600 MHz antenna indicated the presence of a discontinuity at 3.5–4 ns (corresponding at 0.1–0.12 m depth), not detectable in the other antennas, which may be due to the presence of organic residuals in the first ten centimeters.


Impact of Data Processing and Antenna Frequency on Spatial Structure Modelling of GPR Data.

De Benedetto D, Quarto R, Castrignanò A, Palumbo DA - Sensors (Basel) (2015)

Graph of correlation matrix for GPR data acquired with 250 MHz antenna and processed with third processing procedure (time zero correction, dewow filter, bandpass filter and envelope). Person’s correlations (r) are reported and all coefficients are significant at 0.05 probability level.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541886&req=5

sensors-15-16430-f005: Graph of correlation matrix for GPR data acquired with 250 MHz antenna and processed with third processing procedure (time zero correction, dewow filter, bandpass filter and envelope). Person’s correlations (r) are reported and all coefficients are significant at 0.05 probability level.
Mentions: Statistical analysis highlighted that GPR data at any frequency and for all procedures showed clear departure from normal distribution, however the addition of further steps in the processing (after the third procedure) caused a more symmetric distribution. In addition, Person’s correlations allowed you to disclose the main reflections observed visually in the radar sections and to evaluate the strength of spatial association between the data at the different depths as function of the processing procedure. The GPR amplitudes at the different times were strongly correlated within an interval of 10–14 ns, for 250 MHz antenna (mainly evident in the data processed with the third procedure, as reported in Figure 5). This time interval may be related to the “second” reflection, which was not detectable visually in the radar sections but only in CMP data. The correlation coefficient showed a discontinuity in the range 10–12 ns for the 600 MHz antenna at the corresponding depth range of 0.3–0.36 m, not evident in the radar sections, which may be due to agricultural tillage. On the contrary, the correlations between the time slices corresponding to the 1600 MHz antenna indicated the presence of a discontinuity at 3.5–4 ns (corresponding at 0.1–0.12 m depth), not detectable in the other antennas, which may be due to the presence of organic residuals in the first ten centimeters.

Bottom Line: The results showed that the type and range of spatial structures of GPR data did not depend on data processing at a given frequency.It was also evident that the noise tended to decrease with the complexity of processing, then the most error-effective procedure was selected.The results highlight the critical importance of the antenna frequency and of the spatial scale of soil/subsoil processes being investigated.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Scienze della Terra e Geoambientali, University of Bari, Aldo Moro, Bari 70125, Italy. daniela.debenedetto@entecra.it.

ABSTRACT
Over the last few years high-resolution geophysical techniques, in particular ground-penetrating radar (GPR), have been used in agricultural applications for assessing soil water content variation in a non-invasive way. However, the wide use of GPR is greatly limited by the data processing complexity. In this paper, a quantitative analysis of GPR data is proposed. The data were collected with 250, 600 and 1600 MHz antennas in a gravelly soil located in south-eastern Italy. The objectives were: (1) to investigate the impact of data processing on radar signals; (2) to select a quick, efficient and error-effective data processing for detecting subsurface features; (3) to examine the response of GPR as a function of operating frequency, by using statistical and geostatistical techniques. Six data processing sequences with an increasing level of complexity were applied. The results showed that the type and range of spatial structures of GPR data did not depend on data processing at a given frequency. It was also evident that the noise tended to decrease with the complexity of processing, then the most error-effective procedure was selected. The results highlight the critical importance of the antenna frequency and of the spatial scale of soil/subsoil processes being investigated.

No MeSH data available.