Nearshore UXO Survey
For nearshore UXO surveys, we tend to deploy a transverse gradiometer (TVG) frame comprising two Geometrics G882 magnetometers with a separation of 1m.
For areas where it is not possible to deploy a gradiometer frame, we tow a single magnetometer at a tight line spacing. The line spacing is typically determined by the threat item identified as part of the desktop UXO study.
Other sensors generally include a multibeam echosounder to measure the seabed bathymetry, a side scan sonar for surface debris and object detection, and a sub bottom profiler, for shallow seismic data acquisition. Assuming the water depth is sufficient, we position the towfish using USBL positioning, or standard layback measurements in the shallowest areas.
The magnetometer data is brought into Oasis montaj for processing before being cross-correlated with the other datasets to allow the creation of target listings.