Fugro Ground Geophysics is a world leader in the acquisition of gravity data using GPS technology. With over half a million gravity stations acquired in conjunction with GPS worldwide, Fugro Ground Geophysics has the experience to manage your programme.

An important part of Fugro Ground Geophysics's experience is in the management of large scale regional helicopter-supported gravity data acquisition programmes: An example of this type of project is the Discovery 2000 gravity programme conducted on behalf of the New South Wales Department of Minerals and Energy. The survey area covered approximately 100,000 square km in remote western New South Wales, Australia.

The various phases of the project included the following:

• Contacting each of the 500 individual landholders in the area to obtain permission for access.
• Before starting the gravity data acquisition, a first order survey network was planned and established throughout the area, a substantial programme in its own right. (This network has been incorporated into Australia's National Survey Network.)
• Planning of logistics such as crew accommodation, helicopter fuel dump placement, and gravity base station locations to reduce flight and travel times
• Acquire survey coordinates and gravity readings at each of the 4,600 stations distributed at four kilometre intervals throughout the area.

At the conclusion of the work, Fugro Ground Geophysics achieved a standard deviation of 8 centimetres for the elevations of the 4,600 points of helicopter positioned data which equated to a five-fold improvement over the contractual specifications.

Fugro Ground Geophysics has also successfully completed a number of large surveys for major oil companies operating in West Africa and East Asia.

With up to eight GPS gravity crews operational during recent field seasons, the technique continues to be the fastest growing ground geophysical method being deployed by Fugro Ground Geophysics world-wide.

This image of gravity data taken at four kilometre intervals from the Darling Basin Gravity Survey of the Discovery 2000 programme, highlights the marked density contrasts between the red tones of the basement rocks of both the Mt. Wintlow High towards the west and the Mt. Jack High towards the north and the blue tones of the Early Palaeozoic sediments of the Darling Basin.

A more detailed analysis of the gravity lows within the Darling Basin (for instance the Nelyambo Trough in the north and the Blantyre Complex in the centre) in conjunction with seismic and magnetic data indicate depths of sediments of up to 10 kilometres in the intense blue area to the western centre of the image.

Such regional data-sets can be of great value in outlining prospective sedimentary basins. (Data shown courtesy of the New South Wales Department of Mineral Resources; geological information courtesy of David Adler, Principal Petroleum Geologist.)