Fugro Airborne Surveys is now offering
the industry leading DIGHEMV helicopter electromagnetic
(HEM) system with fully integrated Digital Signal Processing
(DSP). The DIGHEMV-DSP system offers the
advantages of a fully digital EM system, including automated
airborne calibration, minimal drift, lower noise and
real-time signal processing. It retains the proven DIGHEMV
advantages of tuned coils and long coil separation,
resulting in unsurpassed signal to noise ratios for
a HEM system.
DIGHEMV-DSP system has advantages
gained from:
-
Digitising the EM data at a
rate of 80,000 samples per second;
-
Moving the digitising of the
signal from the helicopter down into the bird;
-
Replacing the analogue electronic
components;
-
Adding a new digital receiver
in the aircraft (pictured above); and
-
Adding tuned calibration coils
in the bird for airborne calibration.
Result from the client's point of view:
- The high sample rate results in the ability to
perform intelligent real-time processing of the
EM information to remove many noise sources from
the recorded data;
- Better reliability of the electronic components
in the field, which improves data quality and minimises
downtime;
- More consistent phase and gain calibration due
to an automated digital calibration procedure performed
airborne, out of ground conductivity effects; and
- Better final interpretation products, particularly
for electromagnetic inversions.
Greg Hodges, Chief Geophysicist, 2000
Case Studies
Helicopter Electromagnetics