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Ground Penetrating Radar GPR. Noggin Plus 250 Configuration. DVL (Digital Video Logger) . cable. Battery. Odometer. Smart Cart. Noggin Plus 250 . Trade-Off Resolution and Antenna Frequency Low frequency Antenna High frequency Antenna

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Noggin Plus 250 Configuration

DVL

(Digital Video Logger)

cable

Battery

Odometer

Smart Cart

Noggin Plus 250


Trade-Off Resolution and Antenna Frequency

Low frequency AntennaHigh frequency Antenna

Long Wavelength Short Wavelength

Decreased Resolution Increased Resolution

Increased Depth Penetrating Decreased Depth Penetrating

Increased size and weight Decreased size and weight


Values of conductivity, relative permittivity, and approximate velocity. (Schultz (2002), Milsom, (2003), Davis and Annan, (1998), and Conyers, (2004)) (After Burger, H. R., 2006).


Equation used to determine the depth, approximate velocity. (Schultz (2002), Milsom, (2003), Davis and Annan, (1998), and Conyers, (2004)) (After Burger, H. R., 2006).d, where c is the speed of light in a vacuum, is the probably one permeability,

and is the relative permittivity.


The attenuation factor (α) can be estimated using equation approximate velocity. (Schultz (2002), Milsom, (2003), Davis and Annan, (1998), and Conyers, (2004)) (After Burger, H. R., 2006).


Theoretical Simulation approximate velocity. (Schultz (2002), Milsom, (2003), Davis and Annan, (1998), and Conyers, (2004)) (After Burger, H. R., 2006).


300 cm approximate velocity. (Schultz (2002), Milsom, (2003), Davis and Annan, (1998), and Conyers, (2004)) (After Burger, H. R., 2006).

GPR Antenna

z

x

250 cm

Dry Sand (r =5, σ =10-5 S/m)

(r = 30, σ = 10-3 S/m)

(r = 19, σ = 0.021 S/m)

Saturated Sand/Clay

Limestone (r = 7, σ = 10-9 S/m)

The model schematic diagram that is used in synthetic simulation of the GPR data. For model 1, the middle layer is saturated sand and it is saturated clay for model 2. r is permittivity and σ is conductivity

y


The top diagram represents the signal for model 1 (the second layer is saturated sand). The bottom diagram is the signal for model 2 (the second layer is saturated clay). The 1st arrow points at the reflection from dry sand-saturated sand (saturated clay for model 2) discontinuity. The 2nd arrow points at the reflection from the saturated sand (saturated clay for model 2)–limestone discontinuity. The 3rd arrow points at the reflection from the bottom of the model



The diagram represents the signal for model 1. The 1st arrow in this waveform points at the onset time of the reflections from the dry sand-the first limestone block discontinuity, and the 2nd arrow points at the onset of the reflections from the second limestone block-dry sand discontinuity. The 3rd arrow indicates the arrival of reflection from the bottom of the model


Schematic diagram of the model geometry used to simulate GPR data to model vertical and reverse faults


The diagram represents the signal for 2nd and 3rd models. The 1st arrow in these two waveforms points at the onset time of the reflections from the dry sand-the first limestone half block discontinuities, and the 2nd arrow points at the onset of the reflections from dry sand-the second limestone half block discontinuity. The 3rd arrow indicates the arrival of reflection from the bottom of the model


Radar Data The 1st arrow in these two waveforms points at the onset time of the reflections from the dry sand-the first limestone half block discontinuities, and the 2nd arrow points at the onset of the reflections from dry sand-the second limestone half block discontinuity. The 3rd arrow indicates the arrival of reflection from the bottom of the model

Processing


Example of GPR profile before and after zero time processing: (top) before processing and (bottom) after processing.


Example of GPR profile before and after horizontal filter and low 500 and high 300 filtering: (top) before processing and (bottom) after processing.


Example of GPR profile before and after background removal processing: (top) before processing and (bottom) after processing.


Example of GPR profile before and after migration processing: (top) before processing and (bottom) after processing.


Lap Experiments processing: (top) before processing and (bottom) after processing.

and

Campus Field work

Using GPR Technique


View of the wooden box used in the laboratory experiments processing: (top) before processing and (bottom) after processing.


Time (ns) processing: (top) before processing and (bottom) after processing.

4 cm

Sand

5 cm

Concrete

20 Cm

Sand

54 cm

Concrete

5 cm

Sand

20 cm

130 cm


Time (ns) processing: (top) before processing and (bottom) after processing.

4 cm

Sand

Sand

Concrete

5 cm

20 cm

54 cm

5 cm

Concrete

20 cm

130 cm


Detection of cavity under Hot Mix Asphalt pavement (top left image). Top right image shows the survey profiles (arrows). 3D GPR image before the cavity excavation (top block) and after the excavation (middle block). Contact between the aggregate and the soil is shown as black line (top block). Blue line in the lower block represents the reflections from the contact between the HMA and the aggregates


  • Conclusions image). Top right image shows the survey profiles (arrows). 3D GPR image before the cavity excavation (top block) and after the excavation (middle block). Contact between the aggregate and the soil is shown as black line (top block). Blue line in the lower block represents the reflections from the contact between the HMA and the aggregates

  • Computer based simulations and controlled laboratory experimentation show that GPR can map variation in lithology and structural setting.


Thank You image). Top right image shows the survey profiles (arrows). 3D GPR image before the cavity excavation (top block) and after the excavation (middle block). Contact between the aggregate and the soil is shown as black line (top block). Blue line in the lower block represents the reflections from the contact between the HMA and the aggregates

Questions


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