GSSI SIR 30, Manual

Page: 89 / 150

Geophysical Survey Systems, Inc. SIR® 30
Manual
MN 93-101 Rev E 83
Dual-Receiver Data Collection Setup
When collecting dual receiver data, the system setup is similar to the Bi-Static setup, however the User
must specify an additional channel for data collection that will operate as a standard, (fixed offset) antenna.
Step 1: Dual Receiver Mode
Figure 124: System Settings- Dual Receiver Collection – 5103 -50400S.
1
Distance Control:
The User should enter the desired horizontal scan density and mark spacing.
2
Unit/Mark:
The User should enter the desired units per mark. This controls the spacing of Distance
Marks written into the data file and onto the data acquisition screen during data collection.
3
Max Units/File:
This is the total expected length of the data file in distance units. If the User knows
what the file length will be prior to data collection then the User should enter the value, otherwise
leave this value at zero (0). The User should use the Sir30 Calc utility to determine the maximum units
per file.
4
GPS:
Select CUSTOM if a GPS system is to be use during the survey. The User must enter the
location of the GPS receiver with respect to the antenna connected to Channel 1. If the GPS antenna is
mounted to the GPR antenna, both the X and Y values will be zero (0).
5
Antenna Entries Antenna 1 - 2:
The User should enter the details of the antennas connected to the
Channel 1 and Channel 2 inputs on the SIR 30. The User should select the default setup values for
both of the antennas
6
The User should then set the TX-RC MODE of each antenna to DUAL RECEIVER. The User will
note that in this setup, FIGURE ## above, we have connected a Model 5103 and a Model 50400S
antenna. While both of these antennas have a 400 MHz center frequency, one antenna is capable of
operating at a higher Xmit Rate, the 504000S.
As indicated in the Note in Chapter 2 (above pp 10), in cases where the maximum Xmit Rate (PRF) of the
antennas connected to the SIR 30 is different, the SIR 30 will use the highest common transmit rate across
all channels i.e. the transmit rate for ALL channels will be equal to the transmit rate slowest channel. In
this case, the SIR 30 will use a 100 KHz Xmit Rate. The Systems Settings menu will display both Xmit
rates.