Utility mapping is used to determine the location of utilities like pipework or wires buried underground. It's a vital part of the civil engineering process, saving time and money on costly reparative work and delays caused by striking utilities. With an accurate utility map, project planners can accurately project costs for work to be done.
However, utility mapping doesn’t come without its challenges. Accuracy of records and mapping has historically posed problems for surveyors as, of course, mapping the location of hidden objects is a task inherently laced with difficulty.
What technologies have been used for utility mapping?
Over the past few decades, the Subsurface Utility Engineering (SUE) sector has developed ways of tackling the challenges associated with locating and mapping underground utility infrastructure. Geophysical technology is used alongside non-technical means such as historical records to gather as much subsurface infrastructure information as possible.
The technologies involved vary, but the most common are:
- Electromagnetic Induction (EMI)
An alternative to the more popular Ground Penetrating Radar (GPR) method, EMI uses an electrical current – supplied by a transmitter – to induce a primary magnetic field. A receiver is set to the right frequency, and deflections of the magnetic field are identified, locating subsurface utilities. EMI can be useful in environments where GPR would be hindered by high-moisture soil, but it can be affected by overlying metal objects.
- Ground Penetrating Radar (GPR)
GPR is the method of choice for utility mapping. It emits directional electromagnetic waves in the MHz and GHz frequency range and uses the signal return to identify where subsurface utility infrastructure is located.
What are the benefits of using GPR for utility mapping?
GPR technology is highly accurate, and it can locate both metallic and non-metallic utilities. Surveyors tend to prefer using GPR to conduct utility mapping surveys as it offers:
- Rapid data acquisition
- Low operation cost
- High-resolution imagery
However, GPR can sometimes be affected by soil moisture, as well as oblique measurements. Using GPR in combination with additional technology, such as radio detection, can provide a more accurate overall utility mapping survey result.
Landform Surveys uses radio detection and GPR to locate and map underground utilities. Our utility mapping surveys guarantee complete accuracy, and results are supplied in CAD format. Speak to us today.