scholarly journals A High-Performance Portable Transient Electro-Magnetic Sensor for Unexploded Ordnance Detection

Sensors ◽  
2017 ◽  
Vol 17 (11) ◽  
pp. 2651 ◽  
Author(s):  
Haofeng Wang ◽  
Shudong Chen ◽  
Shuang Zhang ◽  
Zhiwen Yuan ◽  
Haiyang Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Magnetic Sensor ◽  
Unexploded Ordnance ◽  
Electro Magnetic ◽  
Unexploded Ordnance Detection

Field tests of an experimental helicopter time‐domain electromagnetic system for unexploded ordnance detection

Geophysics ◽  
2004 ◽  
Vol 69 (3) ◽  
pp. 664-673 ◽  
Author(s):  
Les P. Beard ◽  
William E. Doll ◽  
J. Scott Holladay ◽  
T. Jeffrey Gamey ◽  
James L.C. Lee ◽  
...  
Keyword(s):  
Time Domain ◽  
Eddy Currents ◽  
Field Tests ◽  
Field Trials ◽  
Unexploded Ordnance ◽  
Signal Attenuation ◽  
Signal To Noise ◽  
Electromagnetic System ◽  
Time Domain Electromagnetic ◽  
Unexploded Ordnance Detection

Field trials of a low‐flying time‐domain helicopter electromagnetic system designed for detection of unexploded ordnance have yielded positive and encouraging results. The system is able to detect ordnance as small as 60‐mm rounds at 1‐m sensor height. We examined several transmitter and receiver configurations. Small loop receivers gave superior signal‐to‐noise ratios in comparison to larger receiver loops at low heights. Base frequencies of 90 Hz and 270 Hz were less affected than other base frequencies by noise produced by proximity to the helicopter and by vibration of the support structure. For small ordnance, a two‐lobed, antisymmetric transmitter loop geometry produced a modest signal‐to‐noise enhancement compared with a large single rectangular loop, presumably because the antisymmetric transmitter produces smaller eddy currents in the helicopter body, thereby reducing this source of noise. In most cases, differencing of vertically offset receivers did not substantially improve signal‐to‐noise ratios at very low sensor altitudes. Signal attenuation from transmitter to target and from target to receiver causes signals from smaller ordnance to quickly become indistinguishable from geological background variations, so that above a sensor height of about 3 m only large ordnance items (e.g., bombs and large caliber artillery rounds) were consistently detected.

Rao-Blackwellized Unscented Particle Filter for a Handheld Unexploded Ordnance Geolocation System using IMU/GPS

2011 ◽  
Vol 64 (2) ◽  
pp. 327-340 ◽  
Author(s):  
Jong Ki Lee ◽  
Christopher Jekeli
Keyword(s):  
Particle Filter ◽  
Discrimination Performance ◽  
Sensor Technology ◽  
Unexploded Ordnance ◽  
Integration Algorithm ◽  
Detection Systems ◽  
Positioning Errors ◽  
Unscented Particle Filter ◽  
Electro Magnetic ◽  
Non Gaussian

The existence of Unexploded Ordnance (UXO) is a serious environmental hazard, especially in areas being converted from military to civilian use. The detection and discrimination performance of UXO detectors depends on the sensor technology as well as on the processing methodology that inverts the data to infer UXO. The detection systems, typically electro-magnetic induction (EMI) devices, require very accurate positioning (or geolocation) in order to discriminate candidate UXO from non-hazardous items. For this paper, a hand-held geolocation system based on a tactical-grade IMU, such as the HG1900, was tested in the laboratory over a small, metre-square area in sweep and swing modes. A camera position system was used to emulate GPS or alternative ground-based external ranging systems that control positioning errors. The proposed integration algorithm is a combination of linear filtering (Extended Kalman Filter) and nonlinear, also non-Gaussian filtering (Unscented Particle Filter) in the form of the Rao-Blackwellized Particle Filter (RBPF). The test results show that the position accuracy was improved by applying nonlinear filter-based smoothing techniques in both the straight and curved sections of the sweep and swing trajectories.

Paper 7: Hydraulic Vibrators in Automobile Testing with Special Reference to the Rootes Suspension Parameter Rig

1967 ◽  
Vol 182 (2) ◽  
pp. 54-62 ◽  
Author(s):  
R. K. Hodkin
Keyword(s):  
Special Reference ◽  
High Performance ◽  
Dynamic Testing ◽  
Vehicle Suspension ◽  
Substantial Part ◽  
Operating Characteristics ◽  
Electro Magnetic ◽  
Long Stroke ◽  
Vehicle Testing ◽  
Phase Relationships

The principles of the conventional high performance hydraulic vibrator and its operating characteristics are described. An examination is made of the limitations involved and compared to the limitations of electro-magnetic and mechanical vibrators to show significant areas where the hydraulic vibrator has worthwhile advantages. Mention is made of typical applications of hydraulic vibrators to vehicle testing and development. However, a substantial part of the paper is devoted to a specific installation, being a rig primarily designed for the measurement and study of vehicle suspension. This suspension parameter rig essentially consists of four long stroke hydraulic vibrators set in substantial pedestals so that the tyre contact patches of a vehicle may be individually supported and fed vertical inputs. The rig and its associated instrumentation is described in some detail as are its various modes of use from static to dynamic testing up to around 100 Hz. Much of the work carried out on the rig is directly or indirectly associated with vehicle ride. In addition to the ability to feed in single and repetitive waveforms at different phase relationships, road inputs may be simulated.

scholarly journals A New Class of Carbon Nanostructures for High‐Performance Electro‐Magnetic and ‐Chemical Barriers (Adv. Sci. 22/2021)

2021 ◽  
Vol 8 (22) ◽  
pp. 2170148
Author(s):  
Jae Hui Park ◽  
Yun Ji Oh ◽  
Dong Yoon Park ◽  
Joonsik Lee ◽  
Jae Seo Park ◽  
...  
Keyword(s):  
Carbon Nanostructures ◽  
High Performance ◽  
New Class ◽  
Electro Magnetic

scholarly journals A New Class of Carbon Nanostructures for High‐Performance Electro‐Magnetic and ‐Chemical Barriers

2021 ◽  
pp. 2102718
Author(s):  
Jae Hui Park ◽  
Yun Ji Oh ◽  
Dong Yoon Park ◽  
Joonsik Lee ◽  
Jae Seo Park ◽  
...  
Keyword(s):  
Carbon Nanostructures ◽  
High Performance ◽  
New Class ◽  
Electro Magnetic
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