Approach/Philosophy

Society has grown to be dependent on services that are delivered via infrastructure buried in the ground, principally in roadways. The economic and safety implications of disruption to these services can be extremely serious. Not only is there a significant quantity of existing systems, there is also a continual investment in new and replacement systems.
Traditionally, work on buried plant and equipment involves digging a trench, completing the work, and reinstating the filled hole. In recent years, far more use has been and is being made of trenchless technology, which reduces the number and extent of excavations, thus helping reduce, in particular, the level of indirect costs.

Whichever method is used – trench or trenchless – there is an absolute need to understand the nature of the underground environment about to be disturbed when planning new installations and when excavating to maintain existing infrastructure.
Historically, information on the location of underground plant and equipment has come from records held by utility companies. This information, if it exists (and much of it does not) can be inaccurate, incomplete or out of date. It is worth noting that, in Europe, during new installations, about 90,000 incidences of third party damage to gas pipelines are reported every year and 100,000 in USA. There is little doubt that these instances of damage would be reduced by the use of reliable location techniques.

Ground Penetrating Radar (GPR) is very attractive because, amongst the various state-of-the-art methods available, it is the only non-invasive technique capable of accurately locating both metallic and non-metallic buried objects, without prior knowledge of their position.

However, state-of-the-art GPR can provide unsatisfactory performance, especially in terms of penetration depth and poor sensitivity to smaller targets.