Ground Penetrating Radar: Theory and Practice

Description

Ground Penetrating Radar: Theory and Practice is a practical guide to using this powerful underground surveying technique. The author uses her wide experience to explain the critical factors in using GPR and how parameters, such as wavelength, attenuation and loss need to be properly considered to obtain good survey results.

The first chapter introduces the underlying physics and explains the formation of signal patterning. The next two chapters explain the significance of wavelengths for target detection, probing depths and resolution, and demonstrating the variety of signal presentation. Chapter four discusses why survey results are affected by water and air in the soil, and how this may affect depth readings.

Additional chapters discuss a variety of methods for velocity calibration and suggests where they may be useful, challenging soil conditions and potential problem environments, data processing and a suite of useful techniques, amongst other important topics.

The book gives a clear and formative guidance on understanding the critical factors in using GPR, as well as a checklist of surveying considerations.

Key Features

Covers the critical, practical factors in using a ground penetrating radar, including troubleshooting appropriate equipment selection
Explains why wavelengths matter, providing practice calculations
Offers insight into how to spot ringing (echo effects) and air signals, and how to distinguish these from subsurface data
Enables the reader to understand the importance of calibration of transmission velocity and a range of methods

Readership

Civil, Structural, Geotechnical, and Environmental Engineers, Surveyors, those concerned with brownfield site development, those managing a wide variety of Environmental resources and Archaeologists

Table of Contents

1. Chapter 1. Fundamentals of GPR Operation
   1. Abstract
   2. The “Difficulty” Underlying GPR: Visualization
   3. How GPR Works
   4. What Do the Signals Represent?
   5. How Hyperbolas and Lines Are Formed
   6. Layers and Large Objects
   7. Target Location
   8. Implications of the Beam Shape and Survey Direction
   9. The Double y-Axis
   10. Cautionary Note
   11. Reference
2. Chapter 2. Wavelengths and Why They Matter
   1. Abstract
   2. Frequency and Wavelength
   3. Peak Energy
   4. Velocity and Wavelength
   5. Maximum Depth of Penetration
   6. The Smallest Target Which Can Be Detected
   7. Target Spacing—How Close/How Far Apart?
   8. Depth Accuracy
   9. Fitting the Frequency to the Application
   10. Practical Examples of Wavelength Calculation
   11. Reference
3. Chapter 3. More Fundamentals of GPR Operation
   1. Abstract
   2. GPR Detection
   3. What 2D GPR Data Looks Like and Why
   4. Wavelength and Signal Amplitude
   5. Nonhyperbolic Targets
   6. Signal Capture at the Ground Surface
   7. Signal-to-Noise Ratios
   8. Data Presentation: Color and Gray Scale
   9. References
4. Chapter 4. The Effect of Water and Air
   1. Abstract
   2. Transmission Velocity and Misleading Depth Measurements
   3. The “Rule of 3”
   4. Wet Sites
   5. Where Air May Be Present
   6. Examples of Air Gaps
   7. Examples of Subsurface Water
   8. The Importance of Velocity Calibration
   9. Practice Calculations
   10. Answers to Calculations
   11. References
5. Chapter 5. Velocity Calibration
   1. Abstract
   2. Calibration by Curve Fitting
   3. Migration
   4. Known Layer or Layers
   5. Object at Known Depth
   6. Wide Angle Reflection and Refraction
   7. Transmitter With Multiple Receivers
   8. Other Calibration Rules
   9. Consistency With Site Conditions
6. Chapter 6. Attenuation or Loss
   1. Abstract
   2. Attenuation
   3. Total Attenuation
   4. Degrees of Attenuation
   5. Electrical and Magnetic Losses
   6. Near Surface Reflectors
   7. Freshwater
   8. Soil Analysis
   9. Footnote About Clay, Concrete, and Sand
   10. Why a Working Knowledge of GPR Limitations Matters
   11. References
7. Chapter 7. Survey Strategies
   1. Abstract
   2. Antenna Frequency
   3. Probing Depths
   4. Preset Probing Depths
   5. Exercise
   6. Sampling Along the Line of Travel of the GPR
   7. Transect Spacing (Sampling Across the Survey Area)
   8. Grids and GPS
   9. Antenna Position
   10. Setting Priorities
   11. Information Required Prior to Survey and Decisions to Be Taken
   12. The Unsuitable Soil Risk
   13. Answers to the Exercise
   14. References
8. Chapter 8. Data Processing
   1. Abstract
   2. Sender/Receiver Correction
   3. Time Zero Removal
   4. Background Removal
   5. Gain
   6. Bandpass Filters
   7. Stacking
   8. Migration
   9. Sequence Processing
   10. Other Useful Techniques (X-Flip, Cut and Paste)
9. Chapter 9. Antennas and Screening
   1. Abstract
   2. Monostatic/Bistatic Antennas
   3. Bowties, Horns, and Snakes
   4. Borehole Antennas
   5. Antenna Arrays
   6. Size Matters—The Manufacturer’s Rule of Thumb
   7. Radiation Patterns
   8. Screening
   9. Common Sources of External Interference
   10. Sensitive Sites
   11. Detection of Air and Other Aboveground Surface Signals
   12. References
10. Chapter 10. Three-Dimensional Data
    1. Abstract
    2. Formation of Three-Dimensional Data
    3. Line Placement Exercise
    4. Time Slices
    5. Contouring
    6. Amplitude Mapping
    7. Answer to Line Placement Exercise
    8. References
11. Chapter 11. Common GPR Applications
    1. Abstract
    2. Security
    3. Structural Engineering
    4. Roads and Bridge Deck
    5. Airport Maintenance
    6. Crack Detection
    7. Utility Detection
    8. Archeology
    9. Forensics
    10. Environmental and Glaciology
    11. Mining
    12. Detection of Unexploded Ordnance
    13. References
12. Chapter 12. Examples of Practical Problems
    1. Abstract
    2. Case Study 1: The Potential Gas Explosion Problem (Reinforced Concrete)
    3. Case Study 2: Detection to a Depth of 5 m in Reinforced Concrete
    4. Case Study 3: Mosaic Construction and Graves Inside a Historic Church
    5. Case Study 4: A Wetland Archeological Site
    6. Case Study 5: Carbonate Concretions in a Salt Marsh
    7. Case Study 6: A Delaminating Floor in a Supermarket
    8. Case Study 7: Detection of UXO in Redeposited Earth
    9. Case Study 8: Bridgedeck Construction
    10. References
13. Chapter 13. Multichannel and Single Channel Systems
    1. Abstract
    2. Single Channel Systems
    3. Multichannel GPRs
    4. Duos and Trios
    5. Swept Frequency Systems
    6. Current and Future Developments
    7. References
14. Chapter 14. Reports and Publication
    1. Abstract
    2. Report Title and Introduction
    3. Methodology
    4. Results
    5. Survey Failures
    6. Conclusions
    7. Professional Statement of Indemnity
    8. Further Information
    9. Acknowledgments and References
    10. Appendices
    11. Third-Party Archives
    12. Inappropriate Remarks in Publication
    13. References
15. Chapter 15. Regulation
    1. Abstract
    2. European Licensing of Equipment
    3. Operator Requirements
    4. GPR Operational Requirements: The Code of Practice
    5. GPR Operational Requirements: The Radar Log
    6. European Telecommunications Standards Institute
    7. The EuroGPR and its Role in Licensing Matters
    8. North American Equipment Licensing
    9. GPR and Safety of Transmissions
    10. Other Organizations
    11. References
16. Glossary of Common Technical Terms
    1. Appendix A. Further Reading
       1. Ground Penetrating Radar – General
       2. GPR Engineering
       3. GPR Utility Detection
       4. Environmental GPR Investigations
       5. GPR Forensics
       6. GPR Archeology
       7. GPR Data Processing
       8. GPR Imaging
       9. Unusual GPR Technhical Claims
       10. Journal Papers
       11. GPR Conference Papers
       12. Websites
       13. Scientific Publishers
    2. Appendix B. Professional Association and Reputable Manufacturers
       1. Finding a Reputable Manufacturer
       2. Over Zealous Marketing
       3. EuroGPR Membership
       4. Unusual Technical Claims