seminar report of radar bullet

8/16/2019 Seminar report of radar bullet

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Savitribai Phule Pune University

N.D.M.V.P’ s K.B.T COE, Mechanical Engineering.

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1. INTRODUCTION

Radar bullet is a relatively new discovery used specially for detection of land

mines. And this was very important invention because around 85 countries having problem with landmine, and approximately 20,000 peoples are injured and killed every

year by land mines accidents. In this system, main concentrate is Radar; this ultra wide

band radar provides centimetre resolution to locate even small targets. Radar bullet is

mainly used to find land mines without setting foot into the ground .This consists of

firing a special bullet into ground from a helicopter which could pinpoint buried land

mines even though landmines which remains active for over 50 years after its

implementation. Radar bullet internally consists of microwave emitter. Thismicrowave emitter emits the electromagnetic waves. The bullet emits a radar pulse as

it grinds to halt .This pulse strikes the mine and its image gets available on the

computer in the helicopter thus this method is safe and efficient for finding land mines

[1] .

It is estimated that there are 110 million active buried landmines. That means

one landmines for every 52 people. Landmines are found along roads, in fields andforest, near wells and river bank so it causes serious economic problem for the

countries. As search and removal of buried land mines is serious and problem faced by

many countries, especially countries like Afghanistan, Ukraine, Cambodia and Iraq.

Annually 20000 people are injured and lose their lives only because of landmines

accidents [2]. Clearing mines is very dangerous as for every 5000 mines that are

removed, several persons are killed and injured because main methods used for

demining are mines detection using metal detectors and biological method of detection

by specially trained mine detection dog. But these methods are typically slow,

expensive and dangerous. Hence, new technology of detection of landmines using

radar bullets is effective alternative and this technique is worthy for human being.


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2. LITERATURE REVIEW

The word ''mines'' is derived from the Latin word “mina ” which means vein of

ore and was originally applied to the dug the hole in the ground. The term was then borrowed by military engineers having the job to dig landmines in the ground during

military operation. In order to cause greater destruction experiments had been

conducted in the use of landmines in Sicily and southern Italy. This type of landmines

was known as fougass mine. A fougasses were improved mines constructed by making

a hollow in the ground or rock and filling with explosives like black powder. Firstly

the gunpowder used in landmine was able to absorb moisture and water from air which

consequently losses it's explosive ability. Reference to these mines was made during

the Battle of Williamsburg in 1862, where they adapted shells so as to surprise the

Union vanguard. They consisted of a steel tank, 122 cm (4 feet) X 91.4 cm (3 feet)

broad, and 25 cm (10 inches) deep, which contain very small amount of metal. When

the charge exploded, the light sides of the case were blown out. The Americans are

really the first nation to develop and use operational landmines.

Fig. 2.1 Fougasses Mine


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C. P. Gooneratne, S. C. Mukhopahyay and G. Sen Gupta presented a paper on “ A

Review of Sensing Technologies for Landmine Detection: Radar Bullets” This paper

illustrates the existing and new technologies for landmine detection, such as metal

detection and explosive detection. These ways of detection are dangerous because they

ar e done very close to the mine. A safe method for detecting land mines is “mine

detection using radar bullets”. The conclusion drawn in this paper is that the

conventional methods that are being used right now for mine detection involves

working in close proximity for the mines, so overall mine detection using radar bullets

is a cutting edge technology that is safe and effective.

Prof. Atul Shire, Prof. Umesh Jawarkar, Mr. Sachin Chavhan presented a paper on

“Overview o f Buried Mines Detection Using Radar Bullet” This paper illustrates the

current methods used for detection of land mines, such as Metal detector method,

Biological method and mechanical method. These methods are dangerous and risk is

involved to life of so lider. A safe method for detecting land mines is “mine detection

using radar bullets”. They concluded that the safe method of detection is use of radar

bullets and this can be used for detecting antipersonnel as well as anti- tank mines and

the mines used in sea for targeting the ship and submarines.

Gebremichael T.Tesfamariam and Dilip Mali presented a paper on “ GPR

Technologies for Landmine Detection ” This paper reviewed the development and

applications of Ground Penetrating Radar (GPR) technology to address the challenges

of reliably detecting landmines. They concluded that GPR shows a promise that is; it

seems capable of accurately detecting mines in various environments with few false

alarms.

Patric Blagden in his paper “Mine detection and the need for new technology” has

discussed the need for new technology for landmine detection. He came to a

conclusion that the mine detection and clearance is currently slow, dangerous and

inefficient. He also asserted that the overall aim must be to speed up the demining

process, and make it more reliable and cost-effective.


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3. LANDMINES

The purpose of a landmine is to disable, immobilize or kill. It is an explosive

device activated either by a person or vehicle or by command detonated by electricwire or radio signals. Most land mines are laid on just below the surface of ground and

are activated by pressure or trip-wire. Usually most of the land mines will contain

many metallic parts, which can be made use of in their detection.

Fig. 3.1.1 Landmine

Mines are typically placed in the ground by hand, but there are also mechanical

mine layers that can drop and bury mines at specific intervals. While more than 350

varieties of mines exist; they can be broken into two categories: Anti-personnel (AP)

mines and Anti- tank (AT) mines. The basic function of both of these types of

landmines is the same, but there are a couple of key differences between them. Anti-

tank mines are typically larger and contain several times more explosive material than

anti-personnel mines. There is enough explosive in an anti-tank mine to destroy a tank

or truck, as well as kill people in or around the vehicle. Additionally, more pressure is

usually required for an anti-tank mine to detonate. These devices are typically found


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on or just below the surface of the ground. In order to prevent human life during

detection it is possible to employ radar bullet.

Fig. 3.1.2 Anti-Personal Mine

Fig. 3.1.3 Anti-Tank Mine


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b. Magnetic Sensors:

Magnetic sensors measure a magnetic field. Sending a current through a wire

wrapped around a metal rod or loop produces a magnetic field that penetrates theground. The ground significantly disrupts the magnetic field, which is measured by the

magnetometer.

c. Conductivity Meters:

They use a magnetic field to produce an eddy current in the object. By

establishing a baseline standard in a clean area prior to searching, changes in

conductivity of the soil which may result from conducting substances such as mines

can be detected.

4.2. Biological methods:

a. Use of Dogs and Rats:

Well trained dog can detect the smell of explosives in landmines which is hided

under the grounds. Dog clearly learn to detect mines using odour of explosives and

other chemicals that’s leaks forms buried landmines. Dogs are able to discriminate up

to ten odours without difficulties [3].

Fig. 4.2.1 Dog and Rat Used For Landmine Detection

b. Bees:

Entomologists trained bees that detects explosives and variety of landmines

these bees can search large area in short time. But the thing is to more needs to be


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understood about the fate and transport of explosives in the surface before the full

potentials of trained bees [3].

c. Bacteria:

In this method the process of spraying bacteria on the mine affected areas is

done by airborne system. The bacteria are allowed to grow for several hours. Then

survey team would return to search for fluorescent signal. This method can also cover

large area of detection of mines. But possibly have the environmental limitation [4].

4.3 Mechanical Methods:

a. Prodders and Probes:

The most basic approach to mine detection is prodding. Using prodders, rigid

sticks of metal about 25 cm long; the deminer scans the soil at a shallow angle of

typically 30°. Each time he detects an unusual object, he assesses the contour, which

indicates whether the object is a mine. The probe operator learns through experience to

feel or hear the difference between a mine casing and other buried objects. Probing is

an established step in manual demining. Improved probes could decrease the risks to

deminers by providing feedback about the nature of the object being investigated. In

addition, theoretically, a probe could deliver any of a number of different detection

methods (acoustic, electromagnetic, thermal, chemical, etc.), and the proximity of the

probe to the landmine could improve performance. But probing is dangerous. The

deminer might encounter mines that have been moved or have been placed so that they

are triggered by prodding [6].

Fig. 4.3.1 Mine Detection Using Prodders


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b. Mine Clearing Machines:

When there is not a lot of time for an army to clear a minefield, it will often

employ the use of certain machines to roll through and clear a safe path. Military

forces employ several kinds of mine-clearing machines to clear out or detonate mines.Some machines are specifically designed for the task of mine clearance, while tanks

can also be fitted with certain mine-clearing devices. There are several types of mine-

clearing machines. New machines are remote controlled, which minimizes the risk to

personnel. Mine-clearing machine as shown in figure use one of three techniques,

including flailing chains to beat the ground, rollers to roll over and detonate mines,

and rakes or blades to plough through the minefields, pushing the mines to the side.

These methods are quick and efficient and there is less chance of people gettinginjured during demining. However this leaves the area virtually destroyed. Plus land

for farmers etc. will be destroyed. The machines can easily miss mines [6].

Fig. 4.3.2 Mine Clearing Machine


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4.4 Acoustic / Seismic Methods :

Acoustic/seismic methods look for mines by “vibrating” them with sound or

seismic waves that are introduced into the ground. Materials with different properties

vibrate differently when exposed to sound waves as shown below in figure.

Fig.4.4.1 Amplitude of surface vibration of ground over a mine (solid line) and a blank(dashed line) in response to sound waves.

These methods are complementary to existing sensors with low false alarm rates

and are unaffected by moisture and weather. Existing systems are slow and they do not

detect mines at depth, because the resonant response attenuates significantly with

depth. An additional limitation of existing systems is that moderate to heavy

vegetation can interfere with the laser Doppler vibrometers that are commonly used to

sense the vibrations at the ground surface [6].


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4.5 Ground Penetrating Radar (GPR):

GPR emits pulses into the ground, through a wide band antenna, an

electromagnetic wave covering a large frequency band. Reflections from the soil

caused by dielectric variations (such as the presence of an object) are measured.Moving the wide band antenna reconstructs an image that represents a vertical slice of

the soil; further data processing allows the display of horizontal slices or three-

dimensional representations [5]. Although promising, this technology has limitations.

In particular, the resolution needed to detect small objects involves GHz frequencies,

which decreases soil penetration and increases image clutter. Another constraint is

that, it is expensive as compared to other technologies [10].

The ones currently used GPR systems are beyond the budget of most demining

operations. High frequency GPR improves the resolution of the images of small

landmine and decreasing the penetration capacity and therefore, deeply buried

landmines may cause future problems, as they are difficult to detect.

Fig. 4.5.1 Working Principle of GPR


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5. MODELING / DEVELOPMENT OF SYSTEM

5.1 Radar Bullets:

Radar bullet is a special type of bullet. The main use of radar bullet is to find

landmines without setting foot into the ground. Microwave band have very large

information carrying capacity thus internal structures of radar bullet consist of

microwave emitter. Microwave emitter emits the electromagnetic waves whose

wavelengths are conventionally measured in small number of centimetre called as

microwave.

The bullet emits a radar pulse as it grinds to halt .This pulse strikes the mine and

its image gets available on the computer in the helicopter. Following figure shows

radar bullets that consist of microwave emitter.

Fig. 5.1.1 Radar Bullets

Fig. 5.1.2 Internal Structure of Radar bullet


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5.2 Radar Principle:

Radar is Radio detection and ranging. Radar is a sensor. Radar makes use of

radio waves to detect and locate objects. The purpose is to provide estimates of certain

characteristics of its surroundings most commonly the presence, position and motionof aircrafts, ships and other vehicles [3].

Radar operates by transmitting electromagnetic energy into the surroundings and

detecting energy reflected by object. If a narrow beam of this energy is transmitted by

the directive antenna, the directions from which reflections come and hence the

bearing of object may be estimated. .The distance to the reflecting object in estimated

by measuring the period between the transmission of radar pulse and reception of

echo. In radar bullet principle the change of medium by the waves must be taken into

consideration [8].

Radars have generally from principal parts, the transmitter, antenna, receiver and

display. The transmitter will transmit an electromagnetic signal through the antenna,

which will hit the target and reflects back. The same antenna and the time difference

between the signal transmission and reception is calculated, which will help up tomeasure the distance of the target from the radar.

Fig. 5.2.1 Working Principle of Radar


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5.3 Radar Bullet System:

5.3.1 Hardware Description:

The Radar bullet system consists of a transmitter and a receiver, each connectedto a directional antenna. The transmitter is capable of sending out a large UHF or

microwave power through the antenna. The receiver collects as much energy as

possible from the echoes reflected in its direction by the target and then treats and

displays this information in a suitable way. The receiving antenna is very often the

same as the transmitting antenna. This is accomplished through a kind of time division

multiplexing arrangement, since the radio energy is very often sent out in the form of

pulses.

The impulse radar bullet system was developed in the International Research

Centre for Telecommunications-transmission and Radar (IRCTR). Impulse radar bullet

system comprises Impulse generator, Transmitter, Receiver, Pulse extender, A/D

converter, Processor and Visual display.

a. Impulse Generator:

The pulse generator 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 500MHz till 2GHz on 3dB level. At frequencies

below 1GHz, attenuation losses in the ground are small and considerable penetration

depth can be achieved. However, landmines detection requires down-range resolution

of the order of several centimetres, which can be achieved using frequencies above1GHz. It was found experimentally that the 0.8ns monocycle satisfies penetration and

resolution requirements.

b. Antenna System:

The antenna system is one of the most critical parts of radar bullet system,

because its performance depends strongly on the antenna system. The antenna system

contains transmitter and receiver.


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c. Pulse Extender:

Pulse extender will amplify the ground reflection signal up to the maximum

level acquired by A/D converter.

d. A/D Converter:

The amplified output signal from the pulse extender is given the to the A/D

converter. A/D converter converts the signal into digital signal which passes to the

processor.

e. Processor:

A/D converter converts the signal into digital signal which passes to the

processor. Processor filters the signal. This signal shows presence or absence of

surrogate mine in the soil. Processor allows passing the presence of mine detecting

signal. Processor selects the mine detecting signal and passes to the visual display.

f. Visual Display:

Visual display helps to see the range of targets and it displays the exact position

of landmine.

Fig. 5.3.1.1 Block Diagram of Radar Bullet System


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5.3.2 Working:

To detect mines using this system, a special bullet is fired downward into the

ground, from a gun mounted on a helicopter flying about 100 m above the ground. The

bullet is designed in such a way that it gives out powerful blast of radio waves from

under the ground. The bullet will produce a pulse of radio waves as it pierces the

ground and signal reflected from any landmines within about a 15 meter radius will be

detected by an antenna on the helicopter.

Once the mines are located they can be destroyed at once or their exact positions

are noted so that can be destroyed later. And if the bullet hits the landmine, it would

explode. The Radar pulse which is generated from the bullets is due to a process

known as, “ Magnetic flux compression.”

Fig 5.3.2.1 Experimental Setup


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Magnetic Flux Compression:

Inside the bullet is a metal cylinder, surrounded by a tightly wounded coil of

wire. As the bullet leaves the gun, there is a battery generating a magnetic field in the

cylinder. When the bullet smashes into the ground, the sudden deceleration forces thecylinder out from inside of the coil. The sudden movement of the metal cylinder

through the magnetic field induces a large pulse of current in the coil. The coil thus

acts like an antenna converting the pulse into a short burst of high frequency radiation.

Fig. 5.3.2.2 Magnetic Flux Compression


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6. SUMMARY AND DISCUSSION

6.1 Comparison between the Landmine Detection Techniques:

Technique Sensor Complexity Cost Speed Safety False Alarm

Biological

Detection

Dogs Low Medium Medium Medium Medium

Rodents Low Low Low High High

Bees Low Medium Low High High

Bacteria Medium Medium High Low Low

Electro

Magnetic

Detection

MD Low Low Low High High

GPR Medium High Medium High Low

IR Medium High Medium Medium Medium

Radar

BulletsMedium High High High Low

Acoustic

DetectionA/S Medium High Medium High Low

Mechanical

Detection

Prodders Low Low Medium Low High

Clearing

MachinesMedium Medium High Low High

Table 6.1.1 Comparison between the Landmine Detection Techniques [11]

6.2 Advantages:

1. The light weight system can be fitted to any helicopter i.e. the gun antenna

computer controllers etc.


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7. FUTURE PROSPECTS

1. As the UN has already implemented a worldwide ban on antipersonnel mines, the

invention of radar bullet helps to speed up the destruction of the mines.

2. Ten thousands of anti - personal mines lied buried in the hilly regions of Cambodia /

north - Korea / Afghanistan etc. And according to UN it would take more than 100

years to detect and destroy these, if worked out manually. Mine clearance or demining

is normally broken into three stages; Detection, Removal and Disposal. Current

detection methods range from high tech electronic [ground penetrating radar infrared,

magnetic resonance imaging] to biological detection schemes (dog snuffers and insector bacteria ) to simple brute forces detection methods (Rails, Rollers and ploughs) and

use of handheld mechanical plodders .Most of these methods are very slow and/or

expensive and suffer from a high false alarm rate. So with helicopter and radar bullet,

the mines can be cleared easily.

3. It could help geologists surveying for oil, minerals and other buried natural

resources.

4. This can be applied in future space travels, when we go to a different planet, in that

case we can shoot this bullet in to the ground and detect mineral deposits and other

deposits.


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8. CONCLUSION

Mines are major cause of concern in many countries. Detection and removal of

mines is very important as it is hazardous to both man and animals alike.

The conventional methods that are being used right now for mine detection

involves working in close proximity for the mines, so overall mine detection using

radar bullets is a cutting edge technology that is safe and effective.

With all its advantages it may be hoped that mine detection using radar bullets

will be more used in detection of mine there by making the world a safer place to livein.


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REFERENCES

1. C. Elachi, Introduction to the Physics and Techniques of Remote Sensing , Wiley &

Sons, New York 1987.

2. J. E. Hilland, et al.,”Future NASA Spaceborne S A R Missions,” IEEE-AES Systems

Magazine , Vol. 13, No.1 1, November 1998.

3. Prof. Atul Shire, Prof. Umesh Jawarkar, Mr. Sachin Chavhan, “ Overview of Buried

Mines Detection Using Radar Bullet ’’, Department of EXTC, J.D.I.E.T., Yavatmal,

India, IJESRT, February, 2015.

4. Biological Systems (Paper I) Robert S. Burlage, University of Wisconsin 2nd

International Conference on Autonomous Robots and Agents. December 13-15, 2014

Palmerston North, New Zealand 407.

5. D. J. Daniels, Ground penetration Radar, 2nd Ed, Institute of Electrical Engineers,

London United Kingdom, 2004.

6. C. P. Gooneratne, S. C. Mukhopahyay and G. Sen Gupta, “ A Review of Sensing

Technologies for Landmine Detection: Radar Bullets”. Institute of Information

Sciences and Technology, Massey University, Palmerston North, New Zealand,

December 13-15, 2014.

7. NtCOLLINS, L., GAO, P. and TANTUM, S., 2001, Model-based statistical signal

processing using electromagnetic induction data for landmine detection and

classification. Proceedings of the 11th IEEE Signal Processing Workshop, Vol.1,

pp.162 – 165 .

8. Radar and Radio Detection -Fredrick Emmons Terman.

9. Landmines and Radio Detecting- Andrew Deerorow.


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10. Gebremichael T.Tesfamariam, Dilip Mali, “GPR Technologies for Landmine

Detection”. Institute of Telecommunications, TechnischeUniversität Darmstadt,

Merckstarsee 25, Darmstadt, Germany ECE Department, Ethiopian Institute of

Technology- Mekelle, Mekelle University, Mekelle, Ethiopia. International Journal of

Computing Science and Communication Technologies, VOL.5 NO. 1, July 2012.

11. Safey A. S. Abdelwaha b, “Efficient and Safe Wireless Multi -Sensor Landmine

Detection System Using Image Fusion through SC-FDMA Transmission ”.

Engineering Department, Nuclear Research Center, Egypt. Volume 2, Issue 4 August

2013.

12. Patric Blagden “M ine detection and the nee d for new technology” . vol 37, no 20,

pp 1250, 2001..

13. Images from www.google.com
http://www.google.com/http://www.google.com/http://www.google.com/

seminar report of radar bullet

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