Ground Penetrating Radar (GPR) is a non-destructive GPR Utility Locating technology that uses radio waves to locate underground pipes and structures. It’s used by engineers, contractors, construction crews, and geologists to identify buried utilities. GPR is a cost effective, fast and safe alternative to digging and drilling. It can also help you save time by pinpointing the location of buried utilities before excavation begins, helping you to avoid costly and dangerous mistakes.


As the ground beneath us becomes more congested with aging infrastructure, rising urbanization, and climate change, it’s becoming increasingly important to have accurate knowledge of underground utilities. Getting this information before digging and/or building allows engineers and surveyors to plan projects and enhance safety.

Using GPR is an efficient and effective technique to detect buried utilities. This is because GPR is able to measure differences in the density of different materials. Because of this, it can be used to locate pipes, cables, conduits, tanks, and other buried objects. Depending on the application, it can also identify void spaces in soil and rock.

As with any radar imaging technique, the accuracy of a GPR Utility Locating system will depend on a number of factors. These include frequency, soil and ground conditions, and the equipment’s performance in those environments.


Whether you are planning a major infrastructure upgrade, installing new pipes or simply relocating an existing utility line, locating underground utilities is crucial. Getting the right information in the right place before digging and cutting can save you time, money and reduce risk.

Ground penetrating radar (GPR) works by sending radio waves into the ground and detecting patterns that reflect back to an antenna when they come into contact with objects in the ground. The effectiveness of GPR varies greatly depending on the depth and composition of soils at the site.

In addition to confirming the presence/absence of existing utilities, GPR Utility Locating is ideal for locating targets that are challenging for pipe and cable locators. These can include abandoned utilities and subsurface anomalies such as sinkholes, voids, boulders and rock ledge which may delay your project and lead to significant cost overruns.

Sentry Mapping Services has a team of trained utility locaters that use state-of-the-art GPR technology to detect buried pipelines, cables, and other conductive materials at your project site. Our real-time GPR data provides you with a complete as-built map of the entire underground infrastructure at your site so you can move forward confidently.


GPR Utility Locating is a cost-effective and non-invasive locating method that can save you time, money and avoid construction mistakes. It’s an effective tool for locating metallic and non-metallic utilities as well as underground storage tanks.

The equipment used for GPR utility locating is a wheeled base unit, radar transmitter, receiver, battery, and a user interface typically read and controlled by a tablet. Higher priced equipment often incorporates GPS and includes a user interface with multiple device access and cloud uploads.

A basic EMI utility locator costs around $5,000. It quickly identifies metal utilities like gas and electric lines, but can’t find plastic pipes or anything more than five meters underground.

GPR combines EM and RF technology to provide more in-depth information about the subsurface. It can also identify void spaces, abandoned utilities, and subsurface anomalies that traditional methods don’t reveal.


GPR Utility Locating is a safe, non-invasive way to survey and locate underground utilities. It provides important information before excavation crews can begin digging and trenching, allowing them to avoid a potential safety hazard and complete the project safely.

Ground penetrating radar (GPR) uses radio waves to scan the earth’s surface for buried objects. These waves refract off of objects below the surface and are captured by the equipment’s receiver, which translates the signals into a map of the area.

Electromagnetic (EM) line locators are a safer alternative to GPR for locating conductive utility lines. They emit electromagnetic waves that reflect off of metallic utility lines and are collected by the EM equipment’s receiver.

Depending on the terrain, EM locators can provide horizonal and vertical position within a few inches of the target utility, making it easier for technicians to navigate an area and make sure they are working within the right limits. In addition, EM can be faster and more accurate than GPR when it comes to tracing metal pipes.