Ground penetrating radar (GPR) is a geophysical locating technique that utilizes radio waves to capture subsurface information with a minimally invasive technology. The big advantage of using the GPR system is the ability to pinpoint locations for underground assets without breaking ground. GPR generates subsurface images using the electromagnetic spectrum (EMS) in the 10 MHz to 2.6 GHz microwave range. These signals transmit through the earth, reflecting off the subsurface structures’ electrical permittivity. The receiving antenna in the GPR system records return signal variations, using the data to generate images indicating the changes in these electrical properties. What does ground penetrating radar detect, and what are its commercial uses?
What Does Ground Penetrating Radar Detect?
How Does Ground Penetrating Radar Work?
Ground penetrating radar systems utilize microwave energy waves ranging in frequency from 1 to 1,000 MHz. The transmitter and receiving antenna are the primary equipment the GPR system uses.
Ground penetrating radar works by the transmitter emitting electromagnetic energy into the material. It records the echoes resulting from interactions with subsurface objects. GPR imaging devices detect variations in ground material composition.
If electromagnetic impulses emitted by the GPR device hit an object, the object’s density determines how the signal reflects, refracts, and scatters. The receiver, or antennae, records and interprets this data in a visual interface. This technology is critical in the mapping of underground utilities or structures.
What are the Advantages of GPR Technology?
There are several reasons to use GPR technology in surveying and other civil applications. It’s a non-evasive technology and doesn’t require any excavation, lowering the environmental impact on local ecosystems during exploration projects. GPR is also cost-effective, giving teams key information about sites before they break ground.
Here are a few of the other benefits of using GPR technology.
- It’s effective and safe for use on public project sites.
- Detection of metallic and non-metallic objects and ferrous and non-ferrous metals.
- Detections of subterranean voids and irregularities.
- Measure the thickness, depth, and dimensions of underground objects.
- Scan and collect data over a wide area without excavation.
- Rapid scanning and faster project management decision-making.
- Regulate frequencies to visualize a range of depths and resolutions.
- Collect data from the site and view it immediately or later in projects.
- Lowered project costs due to no need to commit excavation assets.
- No damage to local landscaping or ecosystems.
- Inexpensive prospecting method for project managers.
GPR for Utility Mapping
GPR is most widely used in the mapping of utility assets. This industry, also known as “Subsurface Utility Engineering” (SUE), is a branch of engineering managing risks involved in coordinating utilities. GPR offers assistance for subsurface mapping, identifying unmarked structures, and excavation projects.
There are significant advantages to incorporating GPR tech in these projects. GPR devices emit a pulse into the ground over a specified area to create a scan. A scan typically involves several pulses. Some of the GPR pulse reflects to the antenna, and the rest travels through the target material and dissipates.
The dissipation rate of the signal varies widely. It depends on the density of the scanned materials. GPR is effective for identifying the following organic materials underground.
- Soil and rock.
- Ice and fresh water.
- Concrete structures.
When the GPR energy pulse enters materials with different electrical conduction properties or dielectric permittivity, it creates a reflection.
The amplitude or strength of the signal results from the contrast in the conductivities and dielectric between the materials. Pulses moving from wet to dry sand produce strong reflections. As a result, the operator gets a clear digital image of what lies beneath.
What Does Ground Penetrating Radar Detect?
Contractors use GPR to identify and locate underground items. These items can range from utility assets to artificial structures like ruins in an archaeological dig. This tool is ideal for use in situations with a significant difference in the electromagnetic properties of the target and the surrounding material.
GPR is commonly used in mapping items consisting of the following materials.
- Organic materials
The application possibilities for this technology are endless, and new ideas for its use are always popping up. The most common uses of ground penetrating radar in commercial applications include the following.
- Locating underground pipes and electrical lines
- Identifying changing ground strata
- Identifying rock obstructions and geological features
- Finding voids or air pockets
- Scanning back-filled locations
- Assessing groundwater tables and bedrock
Precision Surveying & Consulting
Established in 1999, we operate nationwide with vast experience in a diverse range of services. Our products and services are suitable for Industrial, Medical, Data Centers, and Commercial Sites. We employ highly skilled and experienced professionals and a licensed surveyor, licensed in the state of Nebraska, allowing us to process and certify all our data in-house. The security and confidentiality of our client’s data are paramount to our working practices. We bring extensive experience and professionalism to every project and customize our support to your individual needs and concerns.
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