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SUBMITTED TO: SUBMITTED BY:Mr. ALOK KUMAR PAWAN MEENAMs. SUMAN GODARA (PGI/EC/12/065)(PTS COORDINATOR) ECE-B

APRESENTATION

ON SUMMER TRAINING

TAKEN AT

IMD, NEW DELHI

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CONTENTS

STAGE 1◦ IMD Profile◦ Centers Of IMD◦ Services Provided

STAGE 2◦ Radar technology◦ DWR Transmitter

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STAGE 1

ABOUT THE INDIAN METEOROLOGICAL DEPARTMENT

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Company Profile

The India Meteorological Department was establish -ed in Calcutta in 1875

The IMD headquarters were later shift to Shimla in 1905, then to pune in 1928 and finally to New Delhi in 1944

IMD became the first organisation in India to have a message switching computer for supporting its global data exchange.

Now IMD is headed by the director general of meteorology Dr. Laxman Singh Rathore

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CentersOfIMD RADAR

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STAGE 2

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RADARRadar was secretly developed by several nations

before and during World War II. The term RADAR was coined in 1940 by the United State Navy as an acronym for Radio detection and Ranging

Radar is an object-detection system that uses micro-waves to determine the range, altitude, direction, or speed of objects.

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Doppler Weather Radar:-

Weather radar measures the scattering of microwaves used to determine the intensity of precipitation.

This Doppler Weather Radar is a dual polarization weather radar that operates on the C-band RF radio frequency (5 cm, 5.6 GHz).

It uses a coherent klystron transmitter as the source of microwaves.

With sophisticated data processing techniques, the targets can be identified as, for example, rain, hail, or snow

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Principles

A radar system has a transmitter that emits radio waves called radar signals in predetermined directions.

When these come into contact with an object they are usually reflected or scattered in many directions.

If the object is moving either toward or away from the transmitter, there is a slight equivalent change in the frequency of the radio waves, caused by the Doppler Effect.

The reflected radar signals captured by the receiving antenna are usually very weak, they can be strengthened by electronic amplifiers.

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RADAR Cabinet 1 = Waveguide dehydrator 2 = Power distribution unit

(PDU) 3 = Radar receiver 4 = Radar Control Workstation

(RCW) and console for local controlling

5 = Solenoid power supply 6 = HVPS power (high voltage

power supply) for transmitter 7 = Cooling fan 8 = Ventilation ducts 9 = Klystron tube 10 = Solenoid magnet 11=Oil tank for pulse assembly

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Transmitter

Technical and operating characteristics: The transmitter must have the ability to generate the

required mean RF power and the required peak power .

The transmitter must have a suitable RF bandwidth.The transmitter must be easily modulated to meet

waveform design requirements.The transmitter must be efficient, reliable and easy to

maintain and the life expectancyAnd cost of the output device must be acceptable.

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Transmitter 1 = Inlet duct for air cooling 2 = Centrifugal fan 3 = Klystron tube 4 = Solenoid magnet 5 = Oil tank, contains the

pulse assembly 6 = Modulator assembly 7 = Air inlet for transmitter

and solenoid magnet cooling 8 = Exhaust duct to the top

of the cabinet 9 = Arc detector 10 = Waveguide 11 = Air inlet for modulator

cooling

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Block Diagram of Transmitter

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Exciter

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Associated Element

Wave guideCooling subsystemsArc detectionStub tunerHarmonic filtersDehydrator

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Built In Test Equipments

RED- AlarmYELLOW-WarningGREEN- Normal

operation

Bitex Main Screen

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Application Areas

Weather surveillance network operationSevere weather monitoringHydrometric applicationsFlood forecastingAirport wind shear detection (LLWAS integration)Hurricane/Typhoon trackingHail detectionWeather modificationMeteorological researchLaunch support systems

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Advantage

1.High quality of data Doppler radars are used by various industries

because of the high quality of data it provides2. Reliable weather forecasts The data produced by Doppler radars are also

considered reliable enough in terms of forecasting possible heavy rains, thunderstorms, and other types of extreme weather patterns.  

3. More accurate resultsDoppler radars are also used in the aviation industry

and provide accurate results in terms of managing traffic in an airport for example.

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Limitations of Doppler Weather RADAR

The radar though can detect wind it is only through the radial component, thus anything moving perpendicular to the beam is sensed as zero velocity.

The current radar cannot sense fog.All weather radars are normally with pencil

beam operation thus scan time from the lower to the upper limit takes appreciable limits for the cloud to get modified.

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Conclusion

The radar machine give the exact location of object and find velocity, range and position of the object. By the radar data meteorologist forecast about flood, cyclone, Heavy rain fall, and hail they give warning to the people to be careful.

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Key Learning and Outcome

Learning how to work in professional environment.Learning the DWR technologyPunctuality,time evaluation,priority decidingHelped in developing knowledege about the

RADAR technologyImplementation of theoritical knowledge in

practical.

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References

Most of the part is taken from DWR manuals www.imd.comwww.wikipedia.com

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ANY QUERIES?

THANK YOU