1 / 19

A Method for Determining Size and Burial Depth of Landmines Using Ground-Penetrating Radar (GPR)

A Method for Determining Size and Burial Depth of Landmines Using Ground-Penetrating Radar (GPR). Jay A. Marble, Veridian, Ann Arbor, MI Andrew E. Yagle, University of Michigan. OVERVIEW OF TALK. GOAL: Size and burial depth of landmines USING: Ground-Penetrating Radar (GPR)

fia
Download Presentation

A Method for Determining Size and Burial Depth of Landmines Using Ground-Penetrating Radar (GPR)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. A Method for Determining Size and Burial Depth of Landmines Using Ground-Penetrating Radar (GPR) Jay A. Marble, Veridian, Ann Arbor, MI Andrew E. Yagle, University of Michigan

  2. OVERVIEW OF TALK • GOAL: Size and burial depth of landmines • USING: Ground-Penetrating Radar (GPR) • METHOD: Range-Migration Alg. (RMA) • VALIDATION: 10 signatures of actual Russian TM-62M landmines (Army MHK) • RESULTS: Consistent ability to determine: burial depth; diameter; height of landmines

  3. Objectives of Algorithm • Avoid false alarms (use up ceramic disks) • Depth important (mines at most 6” deep) • Size important (used ordnance strewn over) • Metal detectors not enough; need more specific information about possible mines

  4. Battlefield Vehicle Prototype • Army Night Vision Electronic Science • GPR, metal detector, infrared camera • Robot arm will mark mine locations with ceramic disks (arm is not shown at right)

  5. Ground-Penetrating Radar (GPR) • Mine Hunter/Killer: Designed by BAE; • $:Army Night Vision Lab (Fort Belvoir VA) • 20 transmit/receive antenna pairs in front • 256 frequencies; 500 Mhz to about 2 MHz; stepped by 5 MHz

  6. Depth Processing of Data • Continuous-wave stepped-frequency response • Direct measurement of transfer function • Sample every 2 inches in vehicle motion direction

  7. Fourier Transform (FFT) • Response(frequency) is r(f): • Dwell time (one f)=0.15us; • Penetration depth=7m (ε=9) • Step size so no depth aliasing=1.1 MHz

  8. Hyperbola: azimuth (along track) Buried point target located at (x0,z0). Antenna located along track at (x,0).

  9. Significance of Hyperbola • Avoids false alarms due to clutter and noise • Stratified ground appears as straight line • Hyperbola indicates real, localized target • Hyperbola indicates its depth, as well

  10. Range Migration Algorithm (RMA) • Originally: Seismic imaging for oil domes • “Migration” since images in raw data are “migrated” to their correct locations • Later: adapted to SAR by Italians • Frequency-domain migration: 1978 (Stolt)

  11. Range Migration Equations D(kx,kz)=R(kx,w)=2-D space-time Fourier of r(x,t)

  12. RANGE MIGRATION ALGORITHM: DIAGRAM

  13. Experimental Validation: Data • TM-62M anti-tank mine; buried 4”-8” • 6” high=3 pixels@2” for 500 MHz-2 GHz • Measured signature in Virginia clay (lossy) from MH/K above • System calibration off

  14. Experimental Validation: Result Image: top and bottom of mine (7” apart, 10” long) Shadow region between (radar can’t penetrate mine) Depth of top line=6”=correct depth of buried mine Need to estimate permittivity so flat top & bottom Thresholding for binary image makes image clearer

  15. Experimental Validation: Result 10 signatures from same TM-62M mine using MH/K Fairly consistent (a few outliers); biased slightly high Unknown ground truth permittivity a likely problem: Different in free space, underground, in mine itself

  16. Present Work on Landmines • Issue: detection performance post-migration (easier to look for parallel straight lines) vs. detection performance w/pre-migration data (harder to look for hyperbolae, but apply to raw data before migration processing) • Issue: how to look for lines or hyperbolae • Issue: how to combine with other modalities

  17. OBJECTIVE ILLUSTRATION Determine size and depth of landmines using GPR as part of a multimodal detection algorithm APPROACH ACCOMPLISHMENTS Range Migration and phase compensation; Stoltz interpolation Successful detection of Russian mines buried in field from NVESD MH/K

  18. RANGE MIGRATION ALGORITHM: EXPERIMENT USSR TM-62 LAND MINE Army NVESD MH/K Imaging a single point Point-spread response

  19. RANGE MIGRATION ALGORITHM: RESULTS TM-62 measured (6” depth) TM-62 binary reconstructed

More Related