Robot mounted GPR for pipe inspection

Underground pipe inspection represents one of the last frontiers for Ground Penetrating Radar. The near ideal circumstances (low electromagnetic background environment, constant geometry of concrete pipes, reasonable required penetration depth, etc.) are more than offset by operational challenges. These include the need for a reliable apparatus to keep the antennas in constant contact with the pipe wall, a mechanism to hold them at the desired position and the means to communicate the data over long distances (>;1500 ft or 500 m) in often active sewer pipes in various states of flow. Moreover, the interpreted data has to be presented together with the CCTV output to a lay audience. These challenges have been overcome in a patent pending technology code named SewerVUE In-Pipe GPR, or Pipe Penetrating Radar (PPR). This technology significantly impacts subsurface infrastructure condition based asset management by providing previously unattainable measurable conditions. This paper will summarize the PPR technology development, current methodology, identifying assessment applications, and illustrate how PPR presents critical structural information surrounding buried non-ferrous pipes.