BARNARD MICROSYSTEMS LIMITED

developing new technology for  your exploration activities...

unmanned air ...

geological survey

Geological survey

• “In the case of petroleum exploration, wells are seldom targeted using only one exploration method. Seismic surveys are almost always included. As a consequence, there is hardly ever a direct link between a single exploration method and the discovery of hydrocarbons.”

- BHP Billiton in www.sgl.com  Sander Geophysical.

• Geological surveys, for which a UAV is ideally suited to criss-cross a region under computer control for up to 30 hours at a time, using GPS signals and precision flight control, to follow an exact flight path. The value of a  UAV is its ability to operate in a “low, slow, fly mode”, down to 20 m above ground level,to get better resolution.
• The typical cost of a manned aircraft survey is in the range from $15 to $20 per line mile, whereas it drops to $2 to $3 per line mile for a lower cost, pilotless, UAV.

• Geophysical survey work
• Using satellite technology for geophysical survey work
• Survey size and low level flying
• ... survey planning and prediction of line Km required

Geophysical survey work

- from the Financial Times, 13 September 2005

• The small physical size of the UAV and its low metal content relative to that of a manned aircraft, enables the UAV to make less of a perturbation to the magnetic and gravitational fields being measured, enabling more accurate measurements of:

• field strength and field gradient measurements:

• of magnetic field strength (“aeromagnetic”)
• of the vertical and horizontal magnetic field gradients
• of the differential gravity field (gradiometry)

• electromagnetic measurements:

• of electromagnetic phase and magnitude reflection ratios over a wide frequency
• time domain electromagnetic pulse reflection signal measurements
• Ground Penetrating RADAR sensing of ground and rock dielectric constant

• other measurements:

• gamma ray spectrometer and neutron reflection level measurements
• using a photo-ionization detector, to measure ethane levels in the air
• high resolution multi-spectral imaging, including thermal imaging

- from the Financial Times, 13 September 2005

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- from Hart’s Exploration and Production, June 2005

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'The big driver in exploration is to find a way to cover the largest area we can, and obtain data of acceptable quality, all within the budget we have,' explains Summers. 'In a development survey, we might be looking to cover an area of 400 square kilometres. But exploration surveys, in contrast, might cover 10,000 square kilometres.'

from http://www.bp.com/sectiongenericarticle.do?categoryId=9017637& contentId=7031832

BP Frontiers Magazine: Issue 18, April 2007: “Surveys in silicon”.

In a gravity field survey, performed for example using the BHP Billiton gradiometer,the lower the flight altitude and the better the plane hugs the ground (known as a “tight drape” in analogy to a curtain covering a non-flat surface) the higher the resolution of the gravity field plot. Low altitude flying is stressful to a pilot, particularly over long periods of time and is  dangerous, if done at night. This is an ideal application for UAVs.

The FALCON system is a differential gravity meter, or gradiometer.

From www.bhpbilliton.com  Falcon gravity meter

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We have developed a simple airborne survey planner called GeoSurvey, using the above nomenclature. Note that we have converted a Microsoft EXCEL spreadsheet to an HTML script using the SpreadsheetConverter software, and have incorporated the resultant HTML script in this web page. Consequently, depending on the  security setting on your computer, you might be asked whether you would like to allow your computer to run the following  HTML script.

have noticed that the Airborne Survey  Utility can become corrupted. If you find it is not working, please drop me an email and I will upload a working copy of the utility. My email address is   

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