User Manual

Geophysical Survey Systems, Inc. Model 4108F Antenna
System Settings and User’s Notes
MN34-550 Rev A
3
Data Collection Recommendations:
The following software settings are recommended for general Model 4108F data collection.
See the SIR-20 manual for instructions on how to make setting modifications.
Table 1. Recommended data collection settings for Model 4108 antenna.
SIR-20
Transmit Rate 100 KHz
Samples/Scan 512
Scans/Sec: 160
Time Range 20 ns
Bits/Sample 16
Vertical Filter Settings:
IIR High Pass 1 MHz
FIR High Pass 250 MHz
FIR Low Pass 3000 MHz
Position: Signal position should be adjusted so that the latest arriving wavelet of the direct-
coupling is near the top of the scan. This wavelet should always be visible in the data. GSSI’s
post-processing software requires the presence of this wavelet in the data. Figure 2 shows a
typical scan of data with the signal properly positioned.
Figure 2: Typical data scan obtained with Model 4108F and recommended software settings.
Direct-coupling waveform
Pavement surface reflection