Airborne Gravity 2010 - Geoscience Australia

Airborne Gravity 2010
were reported by Boggs et al. (2007). HeliFALCON has several advantages over fixed-wing airborne
gravity gradiometry: a platform with greater agility allowing better terrain following, higher spatial
resolution from flying lower and slower; larger signals from shallow sources and the ability to provide
detailed follow-up without having to resort to ground-based methods. Typical accuracy and spatial
resolution for a HeliFALCON survey is 3 E and 45 m.
Figure 3. The HeliFALCON system photographed at Norm’s Camp, Ekati. The digital AGG is
mounted behind the pilot’s seat, with twin LiDAR systems in a pod mounted below and behind
the cabin. The RESOLVE AEM bird is on the right of the picture. Photo supplied by G. Gooch.
Joint FALCON and electromagnetics
The HeliFALCON system was flown with a RESOLVE frequency-domain electromagnetic system, a
total field magnetometer and LiDAR in a survey over the Ekati project in north-west Canada’s Lac de
Gras kimberlite province during the summer of 2006. This survey successfully detected a number of
kimberlites that were previously unknown despite the intense exploration that had been applied to the
Ekati field in the past. Rajagopalan et al. (2007) describe results near one of these discovered
kimberlites and also note that the HeliFALCON survey demonstrated that over 90% of all known
kimberlites in local test areas had a detectable gravity response.
More recently, in October of 2009, Fugro Airborne Surveys flew the FALCON digital AGG together
with the TEMPEST airborne time-domain electromagnetic system in a CASA 212 twin-engine aircraft
over the Kauring Test Site established near York in Western Australia (Figure 4). This test successfully
demonstrated the joint acquisition of gravity, time-domain electromagnetics and total field
magnetometry in a single survey. No interference was observed between the various technologies.
The Kauring anomaly was shown to have clearly measurable gravity, magnetic and electromagnetic
signatures (Figure 4).
Following the test, the TEMPEST system was removed from the CASA 212 aircraft and it has since
flown a number of successful FALCON surveys in Australia.
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