Calculating Depth; Soil Calibration Values - SPX Radiodetection RD1100 Operation Manual

Hyperbolas are best viewed when subsurface targets are crossed perpendicularly or at a 90
degree angle. The actual position of the object is located at the apex of the hyperbola.

7.3 Calculating Depth

Ground penetrating radar records the time it takes a radio wave to travel to a target and
back; it does not measure the depth to that target directly. Depth to target is calculated
based on the velocity with which the wave travels to the target and back.
To calculate depth:
For the RD1100, velocity is indicated by the Soil Calibration Value, known as Soil Cal. Once
the Soil Cal values are set, the measured depths will be determined accurately (Section
8.6.6)

7.4 Soil Calibration values

Below is a table of common subsurface materials and their corresponding Soil Cal. This is only
a guideline and there is some variation based on the fact that there can be a mixture of different
materials in the subsurface. The soil water content has the biggest influence, by far, on Soil Cal
values.
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Apex of hyperbola is where
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29
the object is located
RD1100 Operation Manual
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