Friday, December 2, 2011

Let's Get (Geo)physical...

One of the more interesting, different, risk laden projects we're doing this year is in the helicopter world.  There is a Danish project called skyTEM that began flying here last week.  It is a huge array slung beneath one of our Bell 212's that is being used to image the ice, the underlying water, sediments, soil and bedrock in order to determine what is happening within the ground beneath our feet--similar to the way a CT scan is a non-invasive glance beneath our skin without leaving a mark.  That majority of the project work will be flown in the Dry Valley's here, focusing on Taylor Valley, Taylor Glacier and later the Barnes Glacier here on Ross Island.
The surrounding area map
Day 1 began with the assembly of the array itself.  The scale of this is huge.  It's about 100' long x 60' wide and flown on a 100-150' long line depending on the amount of background "noise" generated by the helicopter.  The team assembled the antenna like a giant erector set you had as a kid, except its made out of Kevlar and the size of your house.
The giant erector set during assembly
Close up of the Kevlar construction
The frame and rigging on ice
Once we looked it over and gave the okay, one of the Bell 212's flew down with its crew for a closer look and for an onsite brief of how this was going to be flown.  The gear was tested to ensure the array was "talking" to the helicopter providing track and altitude guidance in reference to its desired route of flight. The operation is like non-other that had been flown prior here and was new ground on many fronts.  Lot's of eyes were watching as this was the culmination of many, many months of preparation and work prior just to get the project down here.
Preflight inspection of the rigging
On liftoff, its a delicate, slow and controlled ascent as the initial inspection of all the rigging in-flight is accomplished by the ground handler.  Once cleared, the helicopter continues to climb out of its low hover to near 100' tensioning all the lines.
Initial hoist of the rigging. 
We have liftoff!  1st calibration flight underway, up to 3000' now.
 Once airborne the rig hangs at an angle.  With forward velocity, it generates lift, flies level and can be adjusted to an ideal speed based on the quality of the data and wind conditions. For the initial testing, the rig needs to be flown up to around 3,000' above ground in order to get a baseline signal clear of any background "noise" and be able to determine the fingerprint of the helicopter's electromagnetic signature.

Once complete and operational the flight profile of the rig is to be flown dual piloted at 100' above ground level (AGL) over a challenging valley environment with sloping terrain and glaciers.  Throw in random 50 knot down-valley winds and things get interesting.
The view from below
In-flight preparing to either land or net the helicopter below

All in all it was an extremely successful day.  A couple minor adjustments had to made to the rig and off they went the next day to begin flying the rig throughout the Taylor Valley for the next 2 weeks.

Another report to follow from Lake Fryxell where the team is camped out of currently.  Stay tuned for more...

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