User's Manual

GPR4 Pavement Scanner
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User Manual
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Earth Science Systems, LLC
February
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9
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2019
Copyright © 2019 ESS, LLC. All rights reserved. Page 11 of 27
e. Depth/Time range Users can opt to display the full range, half range, quarter
range, or eighth range. Users may wish to display only a shallow portion of the
usable range when interested in the more shallow portions of the surveyed range
(depth).
f. Velocity of medium The velocity of EM waves is dependent on the material type.
In order to properly convert from time of flight to depth, the velocity of the
medium must selected (see Depth/Time units above). Select the medium type
and the corresponding dielectric constant. The EM velocity is
εν /c=
where v
is the EM wave velocity, c is the speed of light in a vacuum, and ε is the dielectric
constant of the medium.
Air
ε = 1
Dry concrete/indoor/mature - Dry soil
ε = 4
Damp concrete/outdoor - Damp soil
ε = 6.5
Moist concrete/outdoor/young - Moist soil
ε = 9
Wet concrete/outdoor/young - Wet soil
ε = 16
Saturated concrete/outdoor - Saturated soil
ε = 25
g. Distance units Select the units for the horizontal scale on the B-scan
(Centimeters, Inches, Meters, Feet, Seconds).
h. Distance range Select the horizontal range of the B-scan in distance units (10,
20, 50, 100, 200).
Figure 4. The plot configuration dialog.