Magnetometer / Magnetic survey

Pre-dredge inspection, Caltex berthing area Botany Bay

This was a pre-dredge site inspection involving a magnetometer survey and the subsequent production of magnetic contour maps showing ferrous entities in the surveyed area.  The enormous magnetic signature of the steel wharf was ‘doctored’ in the Excel data before being submitted to the contour software. This was to reduce the scope or range of the data to allow the much smaller anomalies to show on the contour map. Anomaly positions are entered into the dredge position software to ensure the dredge does not interfere with known infrastructure such as buried pipes and to avoid unknown anomalies. Critical areas were also examined using side scan to reveal any relevant sea floor protrusions.

Caltex 3

Fergusson / Pandora Expedition

This was a three week archaeological expedition to the Great Barrier Reef near Cape York organized through the Australian National Maritime Museum and sponsored by the Silentworld Foundation. The work consisted of extensive magnetometer surveys on several reef areas, on site assessment of magnetometer data to facilitate diving activities and post processing of magnetometer data into contour maps for further investigation on following trips. The contour map shows part of the wreck site with a distinct line heading NW which did turn out to be an anchor chain associated with the main wreck site.