Electromagnetic Induction E-Sensor for Underwater UXO Detection
Abstract
QUASAR Federal Systems (QFS) endeavored to adapt its innovative underwater capacitive electrode electric field (E) sensors for use in detection of Unexploded Ordnance (UXO) objects in seawater. The system was based around an existing Time Domain Electromagnetic (TDEM) sensor, in which a pulsed magnetic (B) field induces eddy currents in the target. The eddy currents produce a secondary B-field, which in a conducting medium can be detected with either E-sensors or B-sensors. The E-sensor was used to measure decaying eddy currents in a standard UXO-like target. The results were compared to both previously measured B-fields and calculated values for the same target. The E-sensor showed similar response to the B-sensor, with roughly 1/3 the signal-to-noise ratio (SNR) but a broader detection range. The E-sensor data from a steel rod were in excellent agreement, in both shape and amplitude, to the calculated value for a vertical magnetic dipole of moment 0.03 Am2. The UXO detection capability of the QFS underwater E-sensor has been clearly demonstrated. The vector nature of the fields also suggests the sensor could be use for discrimination, using inversion algorithms such as the Time Domain 3-Dipole Model. In future work the detection capability of this sensor will be enhanced and the discrimination potential will be explored.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2011
- Accession Number
- ADA555981
Entities
People
- Yongming Zhang