What are the benefits of GPR technology?
ROI of up to $21 per $1 invested
The use of GPR feeds important data into subsurface utility engineering processes to improve the reliability of subsurface information and geolocation accuracy of buried utilities. There is growing evidence that the use of SUE in infrastructure projects has a positive return on investment.
U.S. Department Of Transportation
ROI of $4.62 per $1.00 invested ‘Cost Savings on Highway Projects Utilizing Subsurface Utility Engineering’ (Purdue University, 1999)
Ontario Sewer and Watermain Contractors Association
ROI of $3.41 per $1.00 invested ‘Subsurface Utility Engineering in Ontario: Challenges and Opportunities’ (University of Toronto, 2005)
ROI of $21.00 per $1.00 invested ‘Subsurface Utility Engineering Manual’ (Pennsylvania State University, 2007)
University of Toronto
ROI of $2.05 to $6.59 per $1.00 invested ‘Evaluating the use of Subsurface Utility Engineering in Canada’ (University of Toronto, 2006)
The use of locating technologies such as GPR assist greatly in improving our understanding of what lies beneath the surface of the ground and other structure and increasingly shows quantifiable benefit in improving the positional accuracy of subsurface infrastructure.
Legislation & Standards
Many countries have deemed the use of GPR a mandatory requirement for such work, which is supported through the implementation of robust standards such as: AS 5488-2013 (Australia), S250 (Canada), NTE INEN 2873 (Ecuador), Malaysia Standard Guideline for Underground Utility Mapping, PAS 128 (UK) and ASCE 38-02 (US).
Subsurface Utility Engineering (SUE)
GPR is a well proven non-destructive geophysical method for the detection and mapping of subsurface infrastructure. Subsurface utility engineering (SUE) professionals routinely use GPR to collect important data concerning the presence and layout of buried utilities and other subsurface assets and infrastructure.
3D Data Capture
The requirement to survey over long distances or larger areas has led to advanced development of GPR systems that comprise multiple GPR antennas. These ‘GPR Arrays’ allow such areas to be surveyed more quickly by collecting several GPR profiles simultaneously and offer full 3D data capture. Routine applications now include utility mapping, archaeological investigations and artefact mapping, road surveys, bridge deck investigations and more.
Operational Benefit Of Real-Time Sampling?
Whilst conventional GPR systems utilizing old designs are still successful, a modern RTS-based GPR system offers several advantages.
An RTS systems does not require the control unit that is central to the configuration of conventional systems. Consequently, there are less cables and inter-module communications, making systems more practical and field friendly.
While conventional systems can rarely be used at speeds higher than 50 km/h (without increasing the point distance), an RTS system may be used at virtually any speed. This equates to quicker surveys and more importantly for road surveys, without disruption to traffic flow.
Since an RTS system gathers data faster, this collection rate is used to lower the system noise floor, which effectively increases the signal penetration depth. To our knowledge, true 16-bit data has never been gathered with conventional GPR systems, whereas an RTS based system may easily exceed 20-bit.
Why would you invest in a conventional GPR system given the clear advantages of RTS?
Often expressed as effective number of bits, or in dB, where 16-bits equals 96dB. This parameter has a direct impact on the penetration depth and a higher number is better.
Nowadays, vehicles are commonly used to facilitate GPR surveys, even over rough terrain. It’s important that the speed of the GPR system matches the survey speed, otherwise the density of data must be reduced, which will compromise results.
Center frequency and bandwidth
These two parameters determine the resolution of the system, i.e. the information content of the gathered data. Higher numbers give more information, but at the expense of depth penetration.
Ease of use
Or user friendliness; not a line item you generally see since it does not directly impact results. However, over the years we’ve encountered many clients who complain about ruining a survey, due to complex settings that they’ve managed incorrectly. An RTS-based system is much more user-friendly and easier to train on and learn, so minimizes such risk.