Shallow Water Marine UXO Detection Survey, United States Marine Corps Base, Camp Lejeune, North Carolina

摘要

The underwater unexploded ordnance (UXO) towed array (UUTA) electromagnetic system designed by 3Dgeophysics.com (3Dg) utilizes modified and improved Geonics, Ltd. electromagnetic (EM)61 metal detection technology. The UUTA system includes a 2.0 m (6.56 ft) wide (two receiver coil) non-contact bottom-skimming sensor platform, a down rigging tow bar, and a hydrofoil control surface mounted on a 6.7 m (22 ft) ThunderJet boat. The system was designed to be used with a 6 to 7 m (20 to 23 ft) long boat in water depths ranging from 1 to 10 m (3.28 to 32.8 ft). It was determined during the demonstration that the maximum wave height in which data collection could be conducted was 1 m (3 ft). The towing system, hydrofoil, and tiller were not designed to withstand greater sea state height, and minor repairs to the UUTA were required after work in higher seas was attempted. The UUTA demonstration was conducted at a former range, which provided a perfect setting for a representative study area. The overall demonstration area was a 180-acre area located adjacent to U.S. Marine Corps Base Camp Lejeune (Camp Lejeune), NC's, BT-3/N-1 impact area, a former bombing and artillery range near Browns Island, a public recreational, boating and fishing area. The survey area, exposed to the open Atlantic Ocean, was subject to rapidly changing weather conditions, rip currents, offshore winds, wave action, and tidal variations.