3-System Setup Parameters
pulseEKKO PRO
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3.2.7 System Stacking
In noisy environments, one way of improving signal to noise is to collect more than one trace at each
survey position, averaging them and recording the averaged trace. This is known as “trace stacking” or
“stacking”. Data quality improves because the noise, which is usually a random addition to the trace, tends
to zero when averaged while the GPR signal is constant, thus increasing the “signal-to-noise ratio”.
Figure 3-4: The concept of “stacking” data. At each data collection point, the trace is collected multiple times. These traces are
averaged together to calculate the data trace that is actually saved. Stacking improves the data quality by improving the signal-to-
noise ratio.
While stacking improves data quality, it may slow down survey production. The more stacks, the longer it
takes to collect data at each survey position. Therefore, it is important to find the optimum number of
stacks that still reveal the target adequately.
This parameter is set under System Setup - GPR Parameters - System Stacking.
While stacks can be set from 1 to 32767, for most surveys, stacking 4 to 64 times is suitable.
Stacking is normally reduced when: 1) the survey objective is looking for very strong responses or 2)
production speed is vital, such as measurements made from a rapidly moving vehicle.
When the system is run in Free Run mode (Section 3.3.1.3: P43), the user can control the speed the
system collects data by increasing or decreasing the number of stacks. Increasing the number of Stacks
has the effect of slowing down the data collection speed of the Noggin system. Decreasing the number of
Stacks has the effect of speeding up the data collection speed of the Noggin system.
