1. Multisensor Landmine Detection System
Waymond R. Scott, Jr., Gregg Larson, Ali-Cafer Gurbuz and James H. McClellan
School of Electrical & Computer Engineering
Georgia Institute of Technology, Atlanta, GA
It is estimated that more than 110 million active mines are scattered in 70 countries
Every month over 2,000 people are killed or maimed by mine explosions.
Landmines are relatively cheap to manufacture but, once deployed, are very expensive and dangerous to remove.
No single sensor can reliably detect all types of buried landmines with a reasonable false alarm rate in all environmental conditions.
Need fast and cheap multiple cooperative sensors working in multimodal sensing strategies in order to achieve an acceptable performance.
Soldier searching for mines
Two TS-50 AntiPersonnel Mines
WIDEBAND EMI SENSOR
GROUND PENETRATING RADAR
SEISMIC ARRAY
Seismic
Source 2
1m Scan Region
Linear Array with 60° Cone Feet
Computer Controlled Three Axis Positioner
Battery Power
Milwaukee V28 Li-ion Batteries
Power Amplifier
Pre-Amplifiers
Reference Transformer
AT Mine Burial at
Dirt Roadbed Site
EMI Array Head
NI Instrumentation:
PXI-1031DC: Chassis AC/DC
PXI GHz Embedded Controller
PXI Bit, kS/s, 2 ADC/ 2 DAC
PXI Bit, kS/s, 4 chan. ADC
Real time display of data
The array can adjust to ground contours of up to 8 inches.
32 Elements spaced 1.35 inches apart.
GPR images the subsurface using the reflected EM waves due to dielectric boundaries.
GPR data aquisition using a network analyzer and positioning are controlled with Labview.
Compressive Sensing (CS) is investigated as a new data acquisition and imaging algorithm for GPR exploiting the sparseness in target space.
In CS, instead of acquiring Nyquist-rate conventional radar data, it is sufficient to acquire a small number of random linear measurements to be able to image the subsurface.
A seismic landmine detection system probes the subsurface using seismic surface waves which excite mechanical resonances of the buried landmines, resulting in increased surface displacements directly above the landmines which were measured using a custom built radar sensor; however, ultrasound, acoustic, and ground-contacting sensors have also been demonstrated.
Acquisition, motion control, instrumentation control, and display is done by Labview. NI instrumentation: 3x PCI-6070E.
Probes the subsurface with time-varying magnetic fields that mostly sense magnetic and conductive materials such as metal indicating that these EMI signatures can be used to discriminate between the targets.
The data is collected in frequency domain using 21 frequencies logarithmically spaced from 300 HZ to 90 KHz
Real time acquisition and display is done at 10 Hz by Labview and NI instrumentation.
Backprojection
Compressive Sensing
Space-Time Domain Data
Instead of measuring 512 time samples at each scan point, CS uses 15 linear measurements and creates a much less cluttered image compared to conventional processing (backprojection).
CS can also be used in stepped-frequency GPRs.
Rayleigh surface and reflected waves from the buried VS-1.6 mine
Field data measurements taken over different types of mines in varying grid locations. Figures indicates that these EMI signatures can be used to discriminate between the targets.
Optimal movements of the array to localize a VS-1.6 AT mine buried 5 cm deep.