GSSI SIR 30, Manual

Page: 69 / 150

Geophysical Survey Systems, Inc. SIR® 30
Manual
MN 93-101 Rev E 63
5
Configure the GPS output COM port parameters to match those of the SIR 30. The User should
consult their GPS manual for the COM port configuration instructions. The
amber LED next to GPS
label on the front panel of the SIR 30 will illuminate and will begin to flash when the SIR 30 detects
incoming GPS data.
6
Measure the in-line (front-back) and cross-line (left-right) offset from the center of the GPR antenna
connected to Channel 1 to your GPS antenna. These offset values must be entered in the Antenna
Entries section of the System Settings menu. These values will be used in RADAN 7 to correct for
GPS\GPR antenna offsets.
Note:
The SIR 30 accepts a NMEA 0183 standard GGA string.
7
Custom Mark: Select CUSTOM MARKS and enter in a Mark Name for custom markers as desired.
Step 3: Data Acquisition Settings
After the User has selected a default setup for the antenna in the Systems Settings menu, the SIR 30 will
load a default time range, scan rate, vertical filters and gain settings. If the User does not select a default
setup, the system will load the last setup used for data collection. Data acquisition settings such as the
Vertical Filters and Gain are for display purposes only. The acquisition parameters will be stored as a
separate file along with the RADAN *.DZT file and will be used by RADAN 7 when the file is opened.
1
Select RADAR CONFIG > SCAN > TIME RANGE. If the User has selected an antenna type from the
Systems Setting Menu, the SIR 30 will load a default time range, sampling and Vertical Filters for the
selected antenna. In many cases, the default range will not be ideal for the specific application at hand
and must be adjusted by the User. In the event the User changes the time range, the User may also
have to make changes to the Samples per Scan.
2
Select RADAR CONFIG > SIGNAL PROCESS > IIR FILTERS.
The User should adjust the filter settings as conditions require. The default Low Pass filter setting is 2
to 2.5 times the center frequency of the antenna and the default High Pass filter setting is
¼ to 1/3 the center frequency of the antenna. GSSI recommends leaving these at the default values
unless necessary.
Note:
The SIR 30 loads IIR vertical filters for all antennas by default.
3
Select SIGNAL PROCESS > FIR FILTERS.
The FIR filters are OFF by default. If the User wishes to use FIR filters, the User should enter the
desired Low Pass (LP) and High Pass (HP) filter values, then select the IIR High Pass and Low Pass
filters and turn them off. The Vertical FIR and IIR filters may be used simultaneously.
4
Select SIGNAL PROCESS > GAIN.
By default, the Auto Gain is ON. If the User has selected an Antenna Type in the System Settings
menu, the default antenna setup will have a specific number of gain points. If the AUTO GAIN servo
is ON, the User may change the number of gain points but not the gain point values. The number of
possible gain points ranges from one (1) to eight (8). The User should use the Auto Gain servo when
configuring the system for data acquisition. After the system has automatically set the gains, the User
can change the gains by setting the gain servo to MANUAL and make the desired gain adjustments.
GSSI recommends that the User collect several test lines prior to conducting a survey to insure that the
gain is not too low.