Sensors & Software pulseEKKO, Product Manual

Page: 157 / 251

Collecting Data
145
However, it will also filter out other flat-lying responses, such as soil boundaries, so be careful
when using the filter option if your target is flat.
It works by applying a running-average background subtraction to the data set, defined by the
filter width or a window.
This window “moves” across the data and the result is subtracted for
every trace in the data set. The Filter is variable and pressing this button cycles between OFF
and values 1 to 5 (Figure 7-14).
The lower the number, the longer the filter width, and the more “relaxed” the filter. Only the
longer flat-lying features get removed.
The higher the number, the shorter the filter width, and the more “aggressive” the filter. This
results in the removal of long and short flat-lying features.
Pressing OFF turns the filter off completely.
Figure 7-14: Showing variable filter lengths, and Filter Off.
7.1.7 Gain
Since the material being scanned absorbs the GPR signal, deeper targets return weaker
signals. Gain acts like an audio volume control, amplifying signals and making deeper targets
appear stronger in the image. Gain values vary from 1 to 9 where 1 means a minimal
amplification has been applied and 9 means that maximum amplification has been applied.
Pressing this button increments the gain; once you reach 9, it cycles back to 1. Avoid over-