It’s essential to understand what lies beneath the earth’s surface without having to excavate the ground. Ground Penetrating Radar (GPR) is a non-invasive technology that uses electromagnetic waves to study objects and subsurface features. Geophysical technology utilizes electromagnetic signals to collect data on the features found under the surface of the earth.
How Does Ground Penetrating Radar (GPR) Work?
A GPR system consists of a control unit, an antenna, and a power supply. The control unit generates radar energy that is sent underground using the antenna. Additionally, the control unit has a computer hard drive for storage of the collected data. The antenna receives electromagnetic signals from the control unit, amplifies and transmits them underground or other mediums. The electromagnetic waves from the antenna reflect off the objects under the surface. The reflections are then used to generate an image of what lies underground. The frequency of the electrical signals from the antenna determines the depth and clarity of the data.
Therefore, the subsurface features are differentiated from each other using their different electrical properties, for example, rock and water. Data from GPR investigations are available to the user in real-time, making it a fast and relatively cheap method of getting information under the earth’s surface.
Nine Common Uses of Ground Penetrating Radar
GPR is a non-destructive means of finding out the nature of features lying underground for various purposes.
The nine practical uses of GPR in the modern-day world include:
- Determining the location of pipes and cables
- Investigating the thickness of concrete slabs and detection of concrete fractures
- Structural analysis of roads and railway lines
- Mapping of archaeological features and objects
- Mapping of bedrock structure and detection of sinkholes before mining
- Study of the floor of water bodies and detection of water beneath the surface
- Detection of fractures when constructing tunnels
- In the military, for detection of landmines and unexploded devices
- To estimate the depth and study structure of snow
What is the Future Use of GPR?
GPR sensors might find meaningful use as the Artificial Intelligence-based self-driving cars start being operational. It is thought that GPR sensors will work with other existing sensory devices in the vehicle to make the navigation of self-driving cars efficient. The subsurface region is unique to a particular road. When the subsurface is mapped and the data stored, the specific road gets a distinct subsurface pattern. Therefore, as the self-driving car passes over the mapped road, GPR allows the vehicle to compare the road’s underground surface with the pre-existing maps. Thus, the accurate location of the car is understood. GPR is projected to be especially useful when driving over snow where the road’s view is blocked and the GPS signal is weak. A significant amount of work in terms of pre-mapping of roads needs to be done to make GPR use in self-driving cars a reality.
What are the Limitations of GPR?
Some factors limit the maximum use of GPR technology. GPR sensors are not effective in the ground that has a high conductivity because the electromagnetic signals become weak. Additionally, GPR waves do not travel across metallic objects. However, the GOR signals give a distinct ‘ringing’ when they hit a metallic surface. This factor helps to differentiate between metallic and non-metallic objects.
GPR sensors are essential tools for studying subsurface features for various purposes like mining, mapping roads, archaeology, and navigating snow-covered roads safely. The use of GPR sensors helps to conserve the environment by preventing land degradation. Additionally, GPR sensors are set to revolutionize future technology. The advent of self-driving cars will rely heavily on GPR technology as one of the sensor mechanisms.