Ground-penetrating radar (GPR) is a geophysical method that uses radar pulses to image the subsurface.


The Ground Penetrating Radar uses electromagnetic radiation in the microwave band (UHF/VHF frequencies to detect reflected signals from subsurface structures. GPR can be used over a variety of surfaces When the ground conditions are right. Utility Surveyors can use GPR to detect subsurface objects, changes in material properties, and voids and cracks. 

We use the GPR to confirm services and to locate services which are not detectable by other geophysical techniques.

Over the last few years Benchmark Surveys have been expanding their capability to provide utility surveys to PAS 128 Standard. To have an understanding of the buried information across any site that is to be developed is an invaluable asset to the initial design process.


Pipe and cable depths, locations and routes are very important to record from a health and safety, time, and money point of view.


We have staff who have undertaken Sygma utility training in the various detection equipment available including Ground Penetration Radar.


Benchmark Surveys will to the best of our ability identify and locate buried utilities but depending on the nature of the site the percentage of all buried utilities detected will vary.

Full Utility Surveys to PAS 128 Standard

British Standards Institution (BSI) PAS 128 is the current specification for underground utility detection, verification and location. A collaboration between BSI and the Institution of Civil Engineers (ICE) resulted in the PAS 128 standard which requires accurate, quality information to be recorded to a consistent standard with regards to the location of underground utilities. This removes the element of uncertainty, interpretation and resultant variable risk when end users are referring to utility survey reports.

GPR Surveys

Ground-penetrating radar (GPR) is a geophysical method that uses radar pulses to image the subsurface. This nondestructive method uses electromagnetic radiation in the microwave band (UHF/VHF frequencies) of the radio spectrum, and detects the reflected signals from subsurface structures. GPR can have applications in a variety of media, including rock, soil, ice, fresh water, pavements and structures.

In combination with the Ground Penetrating Radar, we also use:

CAT & Genny

A cable locator or cable avoidance tool (CAT) is an instrument used for detecting the presence and approximate location of buried services in advance of undertaking excavation works. It aims to avoid accidents while excavating.

Sondes Drainage

Used to locate buried plastic Water Pipes, Foul Pipes and any other non-magnetic utilities, Sondes are transmitter probes that are attached to the end of a Flexirod. The Sonde is pushed along the pipe, and the position of the sonde detected from above ground level. The entire path of the pipe can be located as long as there are no blockages, if any blockages are met we can mark where the blockage is.

Flexi Tracing

The Flexi Trace rod can be energised by a Radiodetection transmitter or Genny and inserted into pipes as small as 12mm. It is used with a Radiodetection locator or C.A.T to find and trace small diameter plastic pipes

Video Pipeline Inspection

Pipeline video inspections using a flexible rod with a fibre optic camera attached to the end to visually inspect the interiors of pipelines. A common application is to determine the condition of small diameter sewer lines and household connection pipes.

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