GSSI SIR 30, Manual

Page: 74 / 150

Geophysical Survey Systems, Inc. SIR® 30
Manual
MN 93-101 Rev E 68
5
GPS:
When using a GPS system, the User must select CUSTOM from the GPS Type in the Systems
Settings Menu. The User must enter the location of the GPS receiver with respect to the antenna
connected to Channel 1.
If the GPS is behind the antenna, the X value will be the distance behind the antenna, and the number
will be negative. The Y value determines how far to the right or left the GPS is relative to the antenna
connected to Channel 1. If you are standing behind the antenna, facing the direction of your survey
profile, this number is positive if the GPS is to the left of the GPR antenna and negative if the GPS is
to the right of the GPR antenna.
6
Antenna Entries Antenna 1 - 4:
The User should enter the details of the horn antenna(s) connected
to each channel input on the SIR 30. The ANTENNA 1, ANTENNA 2, ANTENNA 3 and ANTENNA
4 options correspond to the Channel 1-4 inputs on the back of the SIR 30. For each antenna, choose the
Type (Center Frequency), antenna model (some will only have one available), orientation (dipole
angle relative to the transect direction), serial number, and antenna offset location relative to the
antenna connected to Channel 1.
Note:
The serial number of the horn antenna must be entered if you are using a Model 4105NR 2 GHz
horn antenna. The serial number of the antenna is matched to a Custom FIR filter file that is stored in
the SIR 30 when operating directly from the SIR 30, or in the laptop when operating with a laptop.
Note:
GSSI ‘smart’ S-model antennas do not require the User to select the antenna type, serial
number, or antenna model The SIR 30 automatically recognizes smart antenna models. The User
should enter the antenna dipole polarity axis orientation.
Step 2: Data Acquisition Setup
1
Select RADAR CONFIG > RADAR.
For antenna models 4105, 4200S 4105A the User must enter the antenna serial number. The SIR 30
system will load a CUSTOM filter file and default time range and gain for the antenna model and
serial number specified.
a)
Set the RUN MODE to DISTANCE.
b)
Set the SAMPLES PER SCAN: When a default antenna setting is loaded, the required number of
samples per scan is set for the specific time range and antenna selected. If the User changes the
default time range, the number of samples per scan may need to be changed to prevent aliasing of
the recorded signal. See RADAR CONFIG > Radar > Samples per Scan for instructions on how to
calculate the correct number of samples per scan.
c)
Set the SCANS/SEC to the maximum value for the selected time range and sampling. To set the
SIR 30 to the maximum scan rate the User should enter a very large number in the SCANS/SEC
window. e.g. ‘999’
d)
Set the DIELECTRIC: The User should enter an approximate value for the media under study. If
the User knows the Dielectric Constant of the media, the value should be entered here. The input
value controls the vertical depth scale of the radar record.
e)
Set the Position and Surface percentage: The User should set the signal position manually and set
the surface percentage to zero (0). The position may need to be corrected so that the Direct
Coupling of the antenna is positioned near the top of the trace window.