Ground-based Radar

The Company's experience both in Ground Penetration Radar(GPR) and other geophysical methods has application to detecting and mapping the location of near-surface pipelines and cables. As early as 1970, thermal infrared mapping (8-14 microns) was used to map lost pipeline routes for oil transportation companies in Texas. The figure below shows the results of one flightline over the area in question. The pipelines can readily be seen. In this case, the lines were operational and show up as 'hot' since the oil being transported generates frictional heat. Another example is shown below, in which the pipeline can be seen only in regions that are not obstructed by vegetation.














Gas lines can similarly be seen and mapped, but with different temperature profiles. In particular, gas leaks cause significant cooling through expansion, and after a while, the surface temperature also becomes cooler as a result, and can be deteted. GPR systems have been used for decades to detect pipelines by use of hand-drawn sleds, but more recently, airborne imaging GPR systems have shown that pipes are readily detected in many different types of soil. As always with GPR,wet, clay-rich soils are not transparent the radar frequencies used, and in these cases, other methods must be found to map the lines. An example of a high definition imaging GPR being used to detect thin wires (anaalgous to pipelines but much harder to detect) is shown below, where the display is a result of manipulating multipolarization images to maximize horizontal conductors. The wires are very clearly visible.




















The Figures below show the effects of conductivity and radar frequency on penetration depth





Airborne GPR imaging systems are not common, and in fact very few of them exist around the World due to the high cost of development and test. IRC is in contact with those flown by non-military groups within the USA, and can assist in solving mapping problems involving pieline routes.



Here are some general links for more information on ground based GPR units;

http://www.ldolphin.org/mycurr.shtml
http://www.g-p-r.com
http://www.cssip.uq.edu.au/staff/noon/gprlist.html
http://www.geophysical.com/applications.htm

For Airborne radar applications, the reader is directed to ;

http://www.sandia.gov/radar/programs.html
http://www.sri.com