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

Munitions Management (MM)
Poster Number 39 – Wednesday
Ground Based Detection and Discrimination — EMI & Magnetometers / Modeling & Processing
HIGH FIDELITY ELECTROMAGNETIC INDUCTION INSTRUMENTS AND
PHYSICALLY COMPLETE MODELS
DR. BEN BARROWES
ERDC-CRREL
72 Lyme Road
Hanover, NH 03768
(603) 646-4822
benjamin.e.barrowes@usace.army.mil
CO-PERFORMERS: Dr. Kevin O’Neill (ERDC-CRREL); Dr. Fridon Shubitidze, Dr. Pablo
Fernandez, and Ms. Irma Shamatava (Dartmouth College)
W
e have developed two advanced, man portable EMI instruments in both the frequency and
time domains intended for queued interrogation of anomalies. The Man Portable Vector
(MPV) time domain EMI instrument (MM-1443) has a single 75 cm diameter primary coil and
five triaxial cubic receivers that measure the secondary vector magnetic field. Initial testing of
the MPV instrument is complete, and we have an extensive data sets collected at the ERDC
teststand, at CRREL, and at Ashland Oregon with Sky Research. Data were collected in both
static mode (MPV stationary) and dynamic mode (MPV moving). We have adapted our
physically complete high fidelity models, the SEA and the NSMC models, to the MPV. The
ArcSecond system provides subcentimeter geolocationing for the MPV. With its high SNR, high
fidelity, high diversity data acquisition capabilities, the MPV provides quality data for UXO
discrimination models.
The GEM 3 D + (MM-1537) is a frequency domain EMI instrument adapted from a GEM 3 from
Geophex. Transverse receivers were added to the GEM 3 to provide the capability of measuring
a vector magnetic field in the frequency domain. Acquiring the transverse components of the
magnetic field offers several advantages including data diversity and partial immunity to
geological noise. The GEM 3 D + also incorporates an advanced geolocationing system. This
positioning system is based on using the instruments own primary field to locate and orient the
primary coil of the instrument. This “beacon” positioning system has an accuracy on the order of
a centimeter when the instrument is within the 3 m of the positioning receiver coils. We have
adapted our physically complete SEA and NSMC models to the GEM 3 D + and will present
inversion results from both statically and dynamically acquired data.
G-7