The benefits of Mobile GPR for Ground Radar Imaging Surveys

The IDS STREAM DP (Dual Polarised) system is a multi-channel ground penetrating radar (GPR) Array system that delivers extended depth range and 3D GPR data acquisition using revolutionary technology to record below ground infrastructure.

The main improvement when changing from a single antenna system to a multi-channel system for ground radar imaging surveys is the ability to rapidly capture high-quality 3D data sets over large areas without any loss of information.

Ground radar imaging surveys are significantly faster with a multi-channel system. Having the channels in Dual Polarisation within the system allows for surveying in both the X and Y direction with a single pass of the unit, rather than requiring separate passes for each direction. The increased 83cm scan width of the antenna needs fewer passes of the antenna due to the larger size of area covered.

The system can be used in a wide variety of environments on-road and off-road. When coupled with SOCOTEC’s road going 4x4 vehicles that operate at up to 9mph, large areas are surveyed on any type of land in a fraction of the time that is required with a single antenna, up to 25 times faster with the multi-channel system. As the Mobile GPR system is road legal and can travel at up to 8mph, it removes the need for traffic management on 30 and 40mph roads.

The multi-channel Mobile GPR system also captures large volumes of 3D data with significantly more accuracy than traditional single channel GPR systems. The data set is positioned using on-board GPS or a total station and interpreted and post-processed using dedicated software.

The 3D data allows for the three-dimensional modelling of the target, a task that is difficult and inaccurate when using single antenna systems. Traditional single antenna GPR systems lack 3D capabilities, which can result in data loss and affect the accurate positioning of targets.

Multi-channel systems are also more likely to be able to identify a target under another target, which single antenna systems will always struggle with. This greater accuracy is also maintained through the ability to cover the entirety of the survey area with Mobile GPR, confirming the position and depth of the targets along the entire route, rather than just at grid intervals. The system can detect non-metallic objects and features, as well as other underground features such as cellars, tramlines, and cobblestones.

Mobile GPR has also proved highly effective at surveying and calculating the void ratio of media in filter drains located adjacent to motorways and major highways, where the off-road capabilities of quad bikes are ideal for towing the STREAM DP multichannel unit and collecting the data over many kilometres in a single shift. The system is capable of covering up to 5ha per day.

The key advantages of using a multi-channel system over more traditional GPR units for ground radar imaging surveys are the density of information gathered and the speed at which it is gathered, providing high-quality data in much shorter periods of time.

SOCOTEC Ireland currently own two Mobile MIRA GPR units for carrying out Mobile GPR Surveys in a variety of environments, with over 12 years of Mobile GPR experience across key safety critical developments.