Wednesday (Group 2) - SERDP-ESTCP - Strategic Environmental ...

Munitions Management (MM)
Poster Number 49 – Wednesday
Ground Based Detection and Discrimination — EMI & Magnetometers / Sensors
TRI-AXIS FLUXGATE-INDUCTION SENSOR FOR ADVANCED TIME-DOMAIN
UXO DETECTION AND DISCRIMINATION
YONGMING ZHANG
QUASAR Federal Systems, Inc.
5754 Pacific Center Boulevard, Suite 202
San Diego, CA 92121
(858) 200-2229
yongming@quasarfs.com
CO-PERFORMERS: Matt Steiger and Dr. Andrew D. Hibbs (QUASAR Federal Systems);
Dr. Robert Grimm (South West Research Institute)
W
e have developed a tri-axial dual-mode magnetic sensor that operates both as a fluxgate to
sense DC magnetic fields and as an induction sensor to sense AC magnetic fields. The
fluxgate shares the same magnetic core, sensing coil and preamplifier as the induction sensor.
The result is a sensor system that is capable of collecting DC magnetic and AC electromagnetic
data in a single sweep; reducing scanning time by 50% and eliminating the need for coregistration
of multiple sensors.
In this presentation, we will describe the development on the tri-axial dual mode fluxgateinduction
sensor system. We will show the ability of using the dual-mode sensor to characterize
target size, shape, and location for a standard 37 mm shell. The performance of the vertical axis
of the sensor was compared to single axis commercial sensors (Geonics EM63 induction sensor,
MEDA mMag001 fluxgate). The performance of the tri-axial QUASAR sensor was compared to
that of the (single) vertical axis. The induction sensor data was analyzed with a three axis time
domain dipole model. The fluxgate data is modeled as a single dipole. In the single axis
comparison, the dual-mode sensor gave similar performance to the commercial sensors, in both
induction sensor and fluxgate modes. Both the QUASAR induction sensor and EM63 were able
to recover a quasi-cylindrical shape for a vertically aligned shell. The fluxgate data yielded the
same target position, to within approximately 1 cm. The three axis induction sensor outperformed
the single axis induction sensor in its ability to characterize target shape. The three
axis sensor returns quasi-cylindrical shapes for both vertically and horizontally aligned shells.
We will also discuss our recent results on the system trade study of the 3-axis dual mode sensor.
The magnetic moment of the transmitter has been increased from 180 A-m 2 to 480 A-m 2 . Data
for standard targets and “canonical objects” (i.e., disks, spheres, cylinders) will be presented.
This project has been supported under SERDP MM-1444.
G-17