• Question: What do you use to detect the pigs and how does it work?

    Asked by 08andreasa to Jamie on 16 Mar 2011 in Categories: .
    • Photo: Jamie Pringle

      Jamie Pringle answered on 16 Mar 2011:

      Hello 08andreasa,

      A good question! I have tried various techniques, but the ones that work best are electrical resistivity and ground penetrating radar.

      Resistivity works by pumping a small electrical current into the ground, and then measuring the voltage between two probes. I have found that decomposition fluids associated with the pigs can be highly conductive and so are a big contrast with higher background resistivity values (as conductivity is the inverse of resistivity). Once you collect a number of data points and grid up the values, the pigs appear as nice low anomalies compared to higher values around it. So I dont detect the pigs, I detect it’s fluids using this method!

      Ground Penetrating Radar (or GPR) works by sending an electro-magnetic wave into the surface, and it will then bounce off an object and we collect the reflected wave. As you move sequentially along a survey line, you can then build up a 2D vertical slice through the ground over which you are profiing. The object should then be easily imaged and you can also determine the depth to the target (a big advantage over other methods).

      Clear as mud?

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