LANDMINE DETECTION USING GROUND PENETRATING RADAR DEVENDER GOUD KALALI 11071A1023
Dec 22, 2015
Contents:
> Introduction> Block diagram> Implementation> Applications> Advantages> Limitations> Future scope> Conclusion
Introduction
> Around every 22 minutes one person some where in the world is killed or injured by a land mine.
> Nearly 50 million unexploded land mines in 60 countries around the world.
> Large portions of land go unused due to fear of mines.
> Modern mines can be constructed with plastics and composites.
Technology used to Detect the landmines:
> Metal detectors
> Nuclear magnetic resonance
> Biological sensors
> Chemical sensors
Hardware description
> Impulse generator(GPR)
> Antenna system
> Pulse extender
> A/D converter
> Processor
> Visual display
Ground Penetrating Radar:> The impulse GPR system has been developed in the International Research Centre for Telecommunications Transmission and Radar(IRCTR).> This ultra wide band radar provide centimetere resolution to locate even small targets.> Two distinct types of GPR Time domain, Frequency domain.> Time domain or Impulse GPR transmits discrete pulses of nano sec duration and digitize the return at GHZ sample rate.> Frequency domain GPR system transmit single frequency & amplitude &phase of the return signal is measured.
Antenna System:
> The GPR system performance strongly depends on the
antenna system.
> The antenna system consist of transmitter and receiver
> The transmit antenna should :
> Radiate Ultra-Wideband
> Radiate Electro-magnetic energy
Pulse extender:
> It will amplify the ground reflection signal upto the
maximum level acquired A/D converter.
> It amplify the samples of digital signals which are converted from analog signal.
A/D Converter:
> The transmitter sends out a series of EM pulses then listens with the receiver connected to high speed samples which in-turn feeds to A/D converter.
> This information is converted from nano sec to milli sec.
> It provides 12 bit accuracy and 66dB linear dynamic range.
Processor:> The processor filters the signals.
> This signals shows presence or absence of surrogate mine in the soil.
> Processor selects the mine detecting signal and passes to the visual display.
Implementation:
> The impulse generator produces 0.8ns monocycle pulse.
> The generator spectrum covers a wide frequency band from 500MHZ on 3dB level.
> After striking the mine, pulses return and are received by the receiver antenna.
ApplicationsGPR has many applications in number of fields:> In case of Earth science it is used to study bedrocks ,soils , ground water and ice.> Engineering applications include non-destructive testing of structures and pavements, locating buried structures and studying of soils.> GPR is used to define landfills contaminant plums and other
remediation sites.> Military uses include detection of mines ,unexploded ordnance and tunnels.
Advantages:
> GPR has accurate measurements.
> GPR locates even a small targets.
> It has been well founded by the defense.
> GPR operates by detecting the dielectric soils when
allows it to locate even no metallic mines.
> GPR has been tested in different environmental
conditions.
Limitations:
> GPR consumes more power.
> Thus false alarms are easily generated from the
background itself.
> The sensors such as GPR are larger and heavier.
References
[1] D. J. Daniels Ed., (2004) Ground Penetrating
Radar 2nd Edition, IEEE Radar, Sonar and Navigation series 15, Institution of Electrical Engineers, London, UK.
[2] C. S. Bristow and H. M. Jol, Ed., (2003) Ground Penetrating Radar in Sediments, Geological Society, Special Publication 211, Geological Society.