Applications of long-range GPR for geotechnical projects are generally related to void detection over large areas and mapping the depth to bedrock. Any radar technology offers the highest resolution of any geophysical method, but it is only applicable to specific geologies. In general, coarse-grained soils and solid rock is best, whereas clays and silts are unsuitable radar environments. However, there are many exceptions to this rule, such as tropical clays (laterites), where UltraGPR can image more than 50 m through.
Karstic voids comprise over 20% of Groundradar’s annual projects. As a general rule, limestone is an excellent radar environment, particularly where there is no surficial weathering present.