Appendix B: Data Interpretation And Examples Of Common Features - GSSI StructureScan Mini XT Manual

Geophysical Survey Systems, Inc.
Appendix B: Data Interpretation and Examples
This section presents some data images of some common targets. While the GPR cannot differentiate
different types of metal (rebar vs. metal conduit vs. post-tensioned cables) on the basis of the signal alone,
the depth, spacing, and direction of the object often gives us clues as to its identification.
Welded Wire Mesh
This image shows a section of 6" wire mesh. There are two main clues here:
1
The even spacing.
2
The change in depth.
Since mesh is produced in a factory to have a constant spacing (6" is typical) the spacing between the
hyperbolas which denote the wires will be constant. Mesh is installed in long rolls and tends to depress as
it is weighted down by heavy concrete during the pour. The result is often a wavy appearance.
Note the bright white dot shown by the orange arrow. This is caused by the energy reflecting off two
adjacent pieces of mesh. The reflections get added together and show as brighter than a single piece. This
is not an additional target.
MN 70-813 Rev E
of Common Features
47
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