Submitted by: Guided by:Naveen Jain Er. Mayanka VatsB.Tech. VIII sem. (E.C Department) I.E.T. Alwar

INTRODUCTIONLandmines and unexploded ordnance (UXO) are a legacy of war.

Landmines kill 26000 people annually. In Cambodia, whole areas of arable land cannot be farmed due to the threat of landmines.

Examples of anti-personnel mines. From left to right: an M14, Valmara69 (a bounding mine), and VS-50:-

Technologies are used for landmine detection are:

Metal detectors Nuclear magnetic resonanceThermal imaging and electro-optical sensorsChemical sensors such as thermal fluorescenceBiological sensors“Ground penetrating Radar”

Ground Penetrating Radar(G.P.R)G.P.R is ultra wide band radar which providescentimeter resolution to locate even small targets

GPR is quite effective in detecting both metal and plastic landmines in a variety of soils

There are two distinct types of GPR :- Time-domain Frequency domain

Block Diagram of G.P.R

Schematic View of G.P.R

HARDWARE DESCRIPTION

Fig 1. Block diagram

Pulse Generator The pulse generator delivered by SATIS Co.

produces 0.8 ns monocycle pulses. The unique feature of this generator is its small trailing oscillations, which are below 2.4% of maximum amplitude during the first 2 ns and below 0.5% afterwards.

The generator spectrum covers a wide frequency band from 500 MHz till 2GHz on 3dB level

Graphically Analysis

Output signal from the 0.8ns generator

Figure 2.

ANTENNA SYSTEMThe antenna system is one of the most critical parts of GPR

systemThe antenna system contains Transmitter and Receiver. Transmitter Antenna :-• Radiate short ultra-wide band (UWB) pulse with small ringing.• Radiate electro magnetic energy within a narrow cone in order to filter out undesirable

back scattering from surrounding objects.• Produce an optimal footprint on the ground surface and below it.

Receiver Antenna :-• Allow time windowing to isolate the direct air wave from the

ground reflection.• Provide sufficient sensitivity in order to receive very weak fields.• Be elevated at least 10cm above the ground surface

OVERVIEW OF THE SYSTEM

Visualizing GPR Data:-The objective of GPR data presentation is to provide a display of the

processed data that is closely approximates an image of the subsurface, with the anomalies that are associated with the objects of interest located in their proper spatial positions.

There are two types of displays of surface data, these are: A SCAN B SCAN

A Scan:-An A-scan (or one dimensional data presentation ) is obtained by a stationary

measurement, emission and collection of a signal after placing the antenna above the position of interest. The collected signal is presented as signal strength vs.time delay.

B Scan:-B scan or Radargram is used to visualize the target of surrogate

mine. This showing the targets at approximately 55 cm and 100

cm. B scan calculating the distance from the soil to the mine. In

this sample radargram showing the exact position. A sample

radargram is shown in figure.

ADVANTAGE:- GPR has accurate measurements. GPR locates even small targets. It has been well founded by the defense.GPR operates by detecting the dielectric soils which allows it to locate even

no metallic mines.Biological sensors can only operate for limited periods, but in GPR has no

such limits.GPR has been tested in different environmental conditions

DISADVANTAGES:-The sensor such as GPR is larger and heavier.GPR is more power hungry.GPR can suffer falls alarm rates as high as metal

detectors.