User's Manual

400 MHz Antenna
The Model 50400S antenna has greatly improved resolution performance over previous GSSI
mid-frequency antennas, such as the Model 3105 (300 MHz). The Model 50400S can be used in
continuous, survey wheel or static stacking modes.
The 50400S
The Model 50400S is a 400 MHz “smart” antenna. This antenna has a special chip in it that will work
with future control units (not the SIR-3000 or SIR-20). This chip will identify the antenna to the SIR-
system control unit so that the controller will be able to automatically load up the correct default settings.
The 50400S will function with a SIR-3000, SIR-20 or any of GSSI’s previous controllers, but the user
will need to manually set the collection parameters on the SIR-system.
System Setup - Standard Settings
Preset Settings:
Range/Depth is approximately 2.5m (8 ft) assuming a dielectric constant of 9.
Setup Mode: Manual
System Run Mode: Survey Wheel (recommended) or Continuous
Range: 50 ns
Number of Gain Points: 5
Vertical Low Pass Filter: 800 MHz
Vertical High Pass Filter: 100 MHz
Samples per Scan: 512
Bits per Sample: 16
Scans per Second: Set to 120 (recommended).
Deep Profiling:
For approximately 5 m (16 ft) with a dielectric of 9.
Setup Mode: Manual
System Run Mode: Survey Wheel (recommended) or Continuous
Range: 100 ns
Number of Gain Points: 5
Vertical Low Pass Filter: 800 MHz
Vertical High Pass Filter: 100 MHz