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Hide removes the markers from the display. This is not permanent; the markers can be made
visible again by selecting Show, which is indicated after Hide is selected.
Select Cancel to exit the Marker Menu.
Note: Markers are saved in a text file with the extension *.mrk. This file get the same name as the
data file.
Select Tools to enter the Tools Menu.
A dropdown menu appears when the Tools Icon is selected.
Set Soil velocity. If the soil velocity has been determined, enter the value by selecting Set Soil
Velocity icon and then use the Navigator to set the correct figure.
Depth Calibration. If the true depth of an item is known, place the antenna so the vertical curser
is positioned over the feature in the radargram, select Depth Calibration to activate the cross-hair
and use the Navigator to position the horizontal curser at the top of the reflector with known depth.
Press the Navigator and enter the value for the true depth. Finally, press the Navigator again to
accept the value and the GX Controller will automatically calculate the velocity based on the entered
value.
Hyperbola fitting. If there is a clear hyperbolic response in the radargram, utilise the Hyperbola
fitting feature to calculate the velocity of the soil. Position the antenna so the vertical curser is over
the hyperbola, press the Navigator to activate the horizontal crosshair and rotate the Navigator to
place the cross-hair on the top of the hyperbola. Press the Navigator to reveal the simulated
hyperbola, now rotate the Navigator to increase or decrease the simulated hyperbola so it “fits” the
true hyperbola in the radargram. Press the Navigator to complete the process; the calculated
velocity will be saved.
Tip: To move the crosshair up and down faster, press down the Navigator and rotate at the same
time.
Migration. This option applies migration to the dataset, which will have the effect of removing the
hyperbola to leave a point in the radargram. First, complete any of the above velocity calculations
to determine the soil velocity and then select Migration to apply the process to the radargram.
Tip:
Accurate calculation of the soil velocity is required for the migration to work effectively. Depth
Calibration is often the most accurate and this should be the first option if available.
