A Multisensor system for the detection and characterization of UXOMM-0437

Gasperikova, Erika ; Becker, A. ; Morrison, H.F. ; Smith, J.T.

Lawrence Berkeley National Laboratory

关键词: Orientation;    54;    Targets;    Detection;    Transients;   

DOI  :  10.2172/919926
RP-ID  :  LBNL--58327-Report
RP-ID  :  DE-AC02-05CH11231
RP-ID  :  919926

美国|英语

来源: UNT Digital Library

【 摘 要 】

A prototype active electromagnetic system has been developedfor detecting and characterizing UXO. The system employs two orthogonalvertical loop transmitters and a pair of horizontal loop transmittersspaced apart vertically by 0.7 m. Eight vertical field detectors aredeployed in the plane of each of the horizontal loops and are arranged tomeasure offset vertical gradients of the fields. The location andorientation of the three principal polarizabilities of a target can berecovered from a single position of the transmitter-receiver system.Further characterization of the target is obtained from the broadbandresponse. The system employs a bipolar half sine pulse train currentwaveform and the detectors are dB/dt induction coils designed to minimizethe transient response of the primary field pulse. The target transientis recovered in a 40 mu-sec to 1.0 msec window. The ground responseimposes an early time limit on the time window and system/ambient noiselimits the late time response. Nevertheless for practical transmittermoments and optimum receivers the size and the ratio of conductivity topermeability canbe accurately recovered. The prototype system hassuccessfully recovered the depths and polarizabilities of ellipsoidaltest targets.