Airborne Gravity 2010 - Geoscience Australia

Airborne Gravity 2010
Figure 4. Spectrogram for Pass 8(S) showing vibrations on the base plate over a period of 559
seconds: (a) magnitude versus frequency; (b) time versus frequency, and (c) isometric view of
the time versus frequency spectrogram. Note the changing amplitude of all frequencies over time
as seen in the isometric view.
Figure 5. We mounted acoustic isolation foam on the sides of the GT-1A during several repeat
line passes in an attempt to reduce acoustic coupling from the propeller through the cabin air to
the GT-1A instrument.
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