GPR Utility Locating: Ground Penetrating Radar
for Safer Excavation and Civil Construction

Check out a short intro to the GPR on YouTube

Excavation Safety: Prevent Utility Strikes with Precise Subsurface Analysis

With the OKM Gepard GPR 3D ground penetrating radar, you can inspect the subsurface in a targeted, reliable way.

811 marks and as-built drawings are often incomplete, and every missed line is a real risk to your crew and your project. The GPR precisely locates active and abandoned utility lines, making the scan your final check before you break ground.

The True Cost of a Utility Strike

Without that final check, even a well-prepared project can go wrong. It happens more often than expected: The contract has been awarded, 811 has been notified, as-built drawings have been reviewed, critical crossings have been potholed, and all lines have been properly marked. Considerable time has already gone into preparation and safety measures.

Yet during excavation, the crew strikes a line in an unexpected location. Work comes to a standstill, and the damaged line must be secured and repaired before the project can move forward. What is often underestimated: The risk of a utility strike extends well beyond the cost of repair. In most cases, the consequences reach much further and affect:

• ! Safety: Striking a power or gas line can cause explosions, electrocution, and serious injuries.
• ! Environment: Damaged oil or fuel lines release pollutants, followed by remediation and regulatory scrutiny.
• ! Schedule: Even a near miss can idle crews and equipment for hours or days.
• ! Cost & liability: Repeated strikes drive up insurance premiums and can cost you future bids.

For contractors, these risks add up fast: emergency response, idle crews and equipment, missed deadlines, and strained relationships with owners and general contractors. Across the industry, the figures show that the repair itself is only a small part of the bill – most of the cost comes from everything that follows. The latest U.S. industry data shows the scale of the problem:

The radar graphs provide an overview of underground utility lines
directly at the construction site.

Why 811 Marks and As-Builts Alone Often Aren't Enough

Calling 811 is the essential first step before any excavation – and required by law before most digging. It gets registered public utilities marked on site. For safe excavation, however, these marks and as-built drawings often fall short. The reasons vary:

• 811 marks typically show only the approximate horizontal location – not the actual depth.
• Position and depth can shift over the years due to ground movement, grading, or fill.
• 811 only covers utilities registered with the local one-call center. Private lines, abandoned lines, and lines that were installed differently than planned, recorded incorrectly, or never documented aren't marked at all – especially on older industrial and oil field sites.

That's why utility locating with GPR is an important safeguard before every excavation. The scan verifies the position and depth of marked utilities and reveals what no record shows. Base your planning on measured data, not assumptions.

How a Survey with the Gepard GPR 3D Works

Before you scan, prepare the area and define the survey grid. Then scan it lane by lane with the Gepard GPR 3D – multiple antennas transmit and receive radar waves across their 40-inch width.

Your field operator has all of the tools they need on the control tablet to make the analysis right there in the field. The 3D visualization on the tablet gives them a visualization of the anomalies found. Location, shape, and depth can all be generally seen in the field.

Afterwards, analyze the data and create reports in the Visualizer 3D Studio Software: identify detected objects and determine their position and depth.

Learn more about analyzing survey data in our GPR tutorial