Determining the Properties and Capabilities of an Existing Experimental Large Loop EM 61 Underwater UXO Detector
Abstract
In response to UXSON-04-03, Dillon Consulting Ltd (DCL) investigated the response of a prototype Large Loop EM61 Marine System. The system was originally conceived in 2002 for a marine UXO survey of Wright's Cove near Halifax, Nova Scotia, to detect accumulations of metal on or below the sea floor at depths of 1 to 15 metres of water. The survey presented new challenges in that the water depths required that sensors be deployed at significant depths, but at the same time contact with the seabed was to be minimized. Dillon Consulting Limited, with assistance from Geonics Limited, modified a high power Geonics EM61-MK2 System by adding a large primary loop transmitter floating on a barge and a submerged receiver mounted on a planing board that was towed beneath the transmitter. The entire system can be purchased for well under $100K (rented for much less) and does not require a special boat for deployment. The specific purpose of this research is to determine if the system response of this equipment can be understood and if necessary improved sufficiently to be used for detailed mapping and demonstration phases. The technology targets the near shore environments of critical concern to SERDP, addressing both very shallow (<15 feet, 5 m) and shallow (16-60 feet, 5-20m) water depths. It provides a novel engineering-based technique and platform that overcomes access limitations for locating UXO present in underwater locations. The project also explores the variations of EM response in underwater environments that must be resolved as a necessary precursor to efforts in improving detection and discrimination in underwater UXO-contaminated areas. The field tests were divided into four phases. The first, third and fourth were undertaken in freshwater and the second in a marine environment. Overall the system preformed much as expected although an issue with electrical communication between the receiver and the transmitter proved bothersome.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2006
- Accession Number
- ADA594402
Entities
People
- Peeter Pehme