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Smart Systems User’s Manual Version 1.1
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Figure 6-8: Proper XY grid surveying pattern.
Following this pattern and starting each line
from the same baseline minimizes the data
editing required to produce a spatially
accurate map of GPR data
Survey Format
The Survey Format specifies how the lines will be collected. The lines shown in Figure
6-6, Figure 6-7, and Figure 6-8 are all collected in the Forward direction only. This
means that each line starts at the X or Y baseline.
When the length of the survey lines are more than about 20 metres, data acquisition
speed may be increased by collecting every second line in the reverse direction (Figure
6-9, Figure 6-10, and Figure 6-11). This is called a Forward and Reverse survey format.
Using forward and reverse format can speed acquisition but can lead to mapping
artifacts called “herringbone” if there are positional errors. It is important that the
odometer is calibrated (Section 6.5.2) and that the Grid Dimensions are correct (Section
6.3.4 – Grid Dimensions).
X Lines Only – Forward and Reverse
Using the Forward and Reverse survey format, X line data are collected in the pattern
shown in Figure 6-9.
Figure 6-9: For collecting GPR data consisting of
long data lines it makes more sense to follow a
forward and reverse surveying pattern. For the
final data to be spatially correct with a minimum
of editing, data collected in this pattern should be
on lines that extend completely from one
baseline to the other.