TRAINING REPORT

OF

SIX WEEKS INDUSTRIAL TRAINING,UNDERTAKEN

AT

DOORDARSHAN KENDRA,JALANDHAR

ON

“TRANSMISSION OF CHANNEL”

SUBMITTED IN PARTIAL FULFILMENT OF

DEGREE

(“B.E-E.C.E-2012”)

Under the guidance of: Submitted by:

Name : Er. Narendra Singh, (IBES) Name: Himanshu Gupta

Dy. Director Genral(E) B120020114

Chitkara University, Himachal Pradesh

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Certificate of Training

This is to certify that Himanshu Gupta, a candidate of B.E. from Chitkara University,

Himachal Pradesh completed 6 week Industrial Oriented Summer Training program at

Doordarshan Kendra, Jalandhar under my guidance and direction.

Er. Narendra Singh, (IBES)

Dy. Director General (E)

Acknowledgement

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We are very thankful to all the persons who with their views and participation

helped us to complete this training successfully. It is with pleasure that we find

ourselves penning down these lines to express my sincere thanks to various people to help

me along the way in completing the training.

We wish to express our deep sense of gratitude to Sh.S.K.Bhatiaour Training Co-

ordinator Mr.Jyotinder Singh AE, Mr. Karnbir Singh AE, Mr. B.S.Bhogal and

other staff member from different departments at Doordarshan Kendra Jalandharfor

their able guidance and useful suggestions, which helped us in completing the

Training.

Lastly, we would like to thank the almighty and our parents for their moral support

and our friends with whom we shared our day-to-day experience and received lots

of suggestions that improved our quality of work.

Preface

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This report is a brief introduction about Doordarshan, enclosing the topics that deal with all

types of applications & with various aspects related to new researches. I hope, this report will

be extremely expedient for grasping the basis knowledge of various fields of communication.

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Contents

Sr. No. Topic Page No.

I Company Profile……………………………………………..6

Prasar Bharti ………………………………………………….6

Doodarshan kendra Jalandhar…………………………………6-7

DD Punjabi……………………………………………………7

II Introduction………………………………………………......8

III Description…………………………………………………....9

III.1 Studio……………………………………………………….....9-24

III.2 ENG……………………………………………………………25-32

III.3 NLE…………………………………………………………....33-34

III.4 Computer section……………………………………………..35-36

III.5 OB……………………………………………………………..37-38

III.6 Earth Station…………….……………………………………..39-45

III.7 Transmitter…………………………………………………….46-56

IV Industry Applications………………………………………. 57

V Future Enhancements………………………………………..58

VI Conclusions…………………………………………………....59

VII Bibiliography………………………………………………….60

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I. Company Profile

I.1 Overview

Prasar Bharti

Prasar Bharti is India's largest public broadcaster. It is an autonomous body set up

by an Act of Parliament and comprises Doordarshan television network and All

India Radio which were earlier media units of the Ministry of Information and

Broadcasting.

The major objectives of the Prasar Bharati Corporation as laid out in the Prasar

Bharati Act, 1990 are as follows:

To uphold the unity and integrity of the country and the values enshrined in

the Constitution;

To promote national integration;

To safeguard citizens’ rights to be informed on all matters of public interest

by presenting a fair and balanced flow of information;

To pay special attention to the fields of education and spread of literacy,

science & technology;

To create awareness about women’s issues and take special steps to protect

the interests of children, aged and other vulnerable sections of the society;

To provide adequate coverage to diverse cultures, sports and games and

youth affairs;

To promote social justice, safeguarding the rights of working classes,

minorities and tribal communities.

To promote research and expand broadcasting faculties & development in

broadcast technology.

DOORDARSHAN KENDRA JALANDHAR

Doordarshan Kendra, Jalandhar also referred as Jalandhar Doordarshan is an Indian

television station in Jalandhar, owned and operated by state-owned Doordarshan,

the television network of Prasar Bharati (Broadcasting Corporation of India). It was

established in 1979, and now produces and broadcasts the 24-hour Punjabi

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language TV channel, DD Punjabi, which was launched in 1998 and covers most of

the state of Punjab, India

The transmission was initially limited to few hours in a day. Besides the regional

language Punjabi, some programmes in Hindi and Urdu were also telecast. Even

programmes in Haryanvi and Himachali languages were telecast from this Kendra

as these states did not at that time have their own Kendras.

With the introduction of Regional Language Satellite Services, all regional centers

of Doordarshan started generating programmes in their respective regional

languages. And thus, DD Punjabi came into existence along with many other

channels of Doordarshan. A satellite earth station built at the cost of 82.5 million

(US$1.4 million), was inaugurated at the station on 7 August 1998, to allow Punjabi

language programs broadcasted from the station, available to neighboring countries

like Pakistan, Afghanistan, Oman, Qatar and Nepal.

DD PUNJABI:Presently, Doordarshan Kendra, Jalandhar telecasts its

programmes under the brand name DD Punjabi. DD Punjabi Channel was launched

in 1998, and it became a 24-hour service within two years. In its terrestrial mode

DD Punjabi has near 100 per cent reach in the State of Punjab. Besides that,

numerous Punjabi viewers residing in different parts of India watch the cultural

programmes broadcast on DD Punjabi with interest.

I.2 Present Status

Doordarshan Jalandhar is the only Programme Production Center in the Jalandhar.

The Studios are housed at Mahavir Marg, Jalandhar and the transmitter is located at

Kharla Khangra. As per the census figure of 2001, the channel covers 89% by

population and 92% by area of Punjab. On 1st May 1995 telecast of DD2

programmes commenced from Jalandhar using a 100W LPT. Now DD2 converted as

DD NEWS is being telecast from 10KW HPT set up in 2000.The reach of News

channel is 45% by area and 67% by population. Presently Kendra originates over

4hrs of daily programmes (25 hrs. & 30 mins weekly).This Kendra originates 2 news

bulletins daily 1 at 5:00 P.M .

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II. Introduction

DDK Jalandhar has the following main departments which manage

the production, storage transmission and maintenance of the two DD

National channels and the DD Punjabi channel.

1. STUDIO (PCR,CAR, Studio A,B,C)

2. ENG Section (VCR , ENG Camera , Editing Booths)

3. NLE/CS( Computer Section, NLE’s & Server Graphics)

4 . OB

5 . DIGITAL EARTH LINK STATION

6 . TRANSMITTER

Each of these departments are discussed in detail with due stress to therelevant

engineering aspects.

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III. Description

III.1 Studio

The studio constitutes:

III.1.1 Studios A,B,C:Doordarshan Kendra, Jalandhar have three main studios named Studio

A, Studio B, Studio C.Each Studio has got its own PCR Room over it. PCR stands for

Programme Control Room.

Requirement of TV studios are:-

- Very efficient air conditioning.

- Uniform and even flooring for smooth operation of camera

- Effective communication facilities.

- Acoustic Treatment

- Studio cameras as per requirement

- Cyclorama and Curtain

- A/V monitoring facilities

- Studio warning lights, safety devices, fire lighting equipment etc.

- Digital equipment.

- Digital Clock.

Hardware provided in Studio Area is:-

- Monitoring facilities for all inputs and output sources.

- Remote control for video mixer an special effects

- Communication facilities with technical area and studio

floor.

- Vision mixing and switching

- Computer Graphics

- SPG

- CCU

- Light control

- Audio Mixing and control

- Monitoring facilities for I/O audio

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Studio A

Studio is the largest studio of Doordarshan Kendra, Jalandhar. This studio is mainly

used to shootthe very renowned programmes likeLishkara, Star-Nite, Sur Sangam,

etc.Studio A consists of 34 lights to control the lighting system and all systems in

studio A are operated manually by worker there.

Studio B

Studio B is multipurpose studio. It is used for shooting various programmes like

sajjari saver , hello doordarshan , krishi darshn , and all discussions Studio B has got

two PCR rooms and 12 Lights over it and one man to control all this.

Studio C

Studio C is the smallest studio of Doordarshan Kendra Jalandhar. This Studio Mainly

used to telecast New Bulletin. Doordarshan Kendra, Jalandhar Telecast News From

regional channel twice a day i.e. 5:00 PM and 7:00 PM.

The output of studio A is continuously checking out at PCR

Lighting system in studio Lighting for television is very exciting and needs creative

talent there is always a tremendous scope for doing experiment to achieve the

required effect . Light is a kind of electromagnetic radiation with a visible spectrum

from red to violet i.e. wavelength from 700 nm to 3800 nm respectively.

Color temperature of various sources

Sum light 5600 K

Studio lamp 3200 K

Domestic lamp 2780 K

Fire 1930 K

Fluroscent 6500 K

Cloudy day 6500 K

Clear Blue sky 12000 K

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III.1.2. PCR:The PCR stand for Production Control Room. The PCR is where the

post production activities like minor editing and management of feed during a live

program takes place. The production manager sits in the PCR and directs the camera

men and selects the angles sound parameters etc during the production stage in the

PCR. It is in the PCR that we can control all the studio lights and all the microphones

and other aspects. The PCR has a vision mixer and an audio mixer. Its working and

other aspects are discussed in detail in the following pages. The PCR is where the

phone in console and other systems are also kept. The PCR usually of the various

equipments like:-

•Camera Control Unit(CCU)

•Vision Mixer(VM)

•Video Tape Recorder(VTR)

•Audio Mixer(AM)

III.1.2.1 Camera control unit or CCU: It is in the studio that all aspects related to

the production of a video takes place. The Camera Control Unit is typically part of

a live television broadcast "chain". It is responsible for powering the professional

video camera, handling signals sent over the camera cable (multicore

cable, triax or fiber) to and from the camera, and can be used to control various

camera parameters such as iris remotely. The CCU contains control for

Aperture

Optical Focus

Zoom of the lens system

Beam Focus

Selecting Gain

Color Temperature

Contours (Camera Details)

Gamma

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III.1.2.2 Vision Mixer (VM):A vision mixer or video switcher enables the program

producer to select the desired sources or a combination of the sources in order to

compose the program. The vision mixer is typically 10x6 or 20x10 crossbar

switcher selecting any one of the 10 or 20 input sources to 6 to10 different output

lines. The input sources include: Camera-1, Camera-2, Camera-3, Telecine-1,

Telcine-2, VTR-1, VTR-2, Test Signal etc. The vision mixer provides the following

operational facilities for the editing of the TV programs.

Take –selection of any input

source, or cut-switching cleanly

from one source to another.

Dissolve-fading in or fading out

Lap Dissolve-dissolving from one

source to another with an overlap

mixing.

Superposition of two sources-keyed

caption when the selected inlay is superposed on the background picture

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Mix:A mix is a transition from one picture to another where the new picture fades in as the

existing picture fades out. During a standard mix transition a superimposition of both

pictures, each at a lower intensity, is visible.

Wipe:A wipe is a transition from one picture to another in which the edge of a shape moves

across the screen, revealing the new picture. Wipe transitions can be applied to background,

to keys, or to both simultaneously. A wipe transition shape can be selected from a variety of

patterns, and these patterns can be adjusted in several ways (position, aspect ratios, edge

attributes, etc.).

Keying: Keying inserts part of one picture into another to create a composite picture.

Keying involves three signals:

• Background,

• Key cut, used to specify where to cut a hole in the background, and

• Key fill, used to fill the hole in the background.

The fill can be an incoming video signal or it can be an internally generated matte fill. A

separate key cut input signal is not necessarily required for keying. For example, a self key

(also called a video key) uses the same input signal for both key cut and key fill.

The KayakDD system supports the following types of keys:

• Additive Key

• Luminance Key

• Linear Key

• Chroma Key

• Preset Pattern

The KayakDD system also supports self keys and split keys.

Examples of Keying Techniques:

Fig: Matte fill luminance keying

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Fig: Linear Keying

Fig: Luminance Keying and Self Key

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Fig: Chroma Keying

Fig: Preset Key

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III.1.2.3. VTR: The VTR is the next section where copies of all programs are stored.

All the programs shot in the camera are simultaneously recorded in the VTR. Also

the VTR plays back all the videos as and when required. Videos of pre-recorded

events are queued up in the VTR and are played back without a break. Videos of

famous people and important events are stored in the central film pool.

III.1.2.4. Audio Mixer: In professional audio, a mixing console, or audio mixer, also called

a mixing desk, audio production console, soundboard or simply mixer is an electronic device

for combining (also called "mixing"), routing, and changing the level, timbre and/or

dynamics of audio signals. A mixer can mix analog or digital signals, depending on the type

of mixer. The modified signals (voltages or digital samples) aresummed to produce the

combined output signals.Mixing consoles are used in many applications, including recording

studios, public address systems, sound reinforcement systems,broadcasting, television,

and film post-production. An example of a simple application would be to enable the signals

that originated from two separate microphones (each being used by vocalists singing a duet,

perhaps) to be heard through one set of speakerssimultaneously. When used for live

performances, the signal produced by the mixer will usually be sent directly to an amplifier,

unless that particular mixer is "powered" or it is being connected to powered speakers.

Among the highest quality bootleg recordings of live performances are the so-

called soundboard recordings that are sourced from this mixer output to the speakers.

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III.1.3. CAR:In broadcast facilities, a Central Apparatus Room (CAR, pronounced

"C-A-R"), central machine room, or central equipment room (CER), or central

technical area (CTA), or rack room is where shared equipment common to all

technical areas is located. Some broadcast facilities have several of these rooms. It

should be air-conditioned, however low-noise specifications such as acoustical

treatments are optional.This is the nerve centre for the TV station, the main activities

in this area include

Distribution of stabilized power supply to different technical area with

protection.

Sync pulse generation and distribution.

Video processing and routing.

Monitoring facilities.

Patch panel for Audio/Video

Electronics for switchers and cameras

Electronics for OFC Link.

Electronics for STL/ Micro wave Link.

Receiving of External/ OB Signal and its distribution.

Main equipments in CAR are

Antenna Tracking System: An antenna tracking system tracks a primary antenna to

follow a moving signal source, such as a communication satellite. A secondary

antenna has a greater beam width than the primary antenna and receives the

same tracking signal from the satellite. The primary antenna is tracked according to a

predetermined search pattern which causes a variation in the signal

amplitudedepending upon the relative location of the satellite and the antenna

position.

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Audio Router:Used for transporting audio signals from inputs to outputs. The

number of inputs and outputs varies dramatically. The way routers are described is

normally number of inputs by number of outputs e.g. 2x1, 256x256. The type of

signals transported - switched can be analogue - Analog - audio signals

or Digital. Digital audio usually is in the AES/EBU standard for broadcast use.

Broadband routers can route more than one signal type e.g. analogue or more than

one type of digital. Because any of the inputs can be routed to any output, the

internal arrangement of the router is arranged as a number of crosspoints which can

be activated to pass the corresponding signal to the desired output.

Character Generator:A character generator, often abbreviated as CG, is a device or

software that produces static or animated text (such as news crawls and credits rolls)

for keying into a video stream. Modern character generators are computer-based, and

can generate graphics as well as text. (The integrated circuit, usually in the form of

a PROM, that decodes a keystroke in a keyboard, and outputs a corresponding

character, is also referred to as a "character generator.

Hardware Character Generators:Hardware character generators are used

in television studios and video editing suites. A desktop publishing-like interface can

be used to generate static and moving text or graphics, which the device then

encodes into some high-quality video signal, like digital Serial Digital

Interface (SDI) oranalog component video, high definition or even RGB video

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Software Character Generators:Software CGs run on standard off-the-shelf

computer hardware and are often integrated into video editing software such as non-

linear editing system (NLE)

Encoder:An encoder is a device, circuit, transducer, software program, algorithm or

person that converts information from one format or code to another, for the

purposes of standardization, speed, secrecy, security, or compressions.

A compressor encodes data (e.g., audio/video/images) into a smaller form

An audio encoder may be capable of capturing, compressing and converting

audio

A video encoder may be capable of capturing, compressing and converting

audio/video

Optical Fibre: An optical fiber (or optical fibre) is a flexible, transparent fiber made

of high quality extruded glass (silica) or plastic, slightly thicker than a human hair. It

can function as a waveguide, or “light pipe”, to transmit light between the two ends

of the fiberOptical fibers are widely used in fiber-optic communications, which

permits transmission over longer distances and at higher bandwidths (data rates) than

other forms of communication. Optical fibers typically include

transparent core surrounded by a transparent cladding material with a lower index of

refraction. Light is kept in the core by total internal reflection. This causes the fiber

to act as a waveguide.

Transceiver: A transceiver is a device comprising both a transmitter and

a receiver which are combined and share common circuitry or a single housing.

When no circuitry is common between transmit and receive functions, the device is a

transmitter-receiver.

Sync Pulse Generator: A sync pulse generator is a special type of generator which

produces synchronization signals, with a high level of stability and accuracy. These

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devices are used to provide a master timing source for a video facility. The output of

an SPG will typically be in one of several forms, depending on the needs of the

facility:

A continuous wave signal

In standard-definition applications, a bi-level sync signal, often with a color

burst signal in facilities that have analog equipment. Typically, this is either in

NTSC or PAL format. As the resulting signal is usually in distinguishable from an all-

black television signal of the same format, this sort of reference is commonly

known as black or black burst

.In some high-definition applications, a tri-level sync signal is used instead.

This signal is virtually identical to the synchronization signal used in component

analogue video (CAV); and is similar to the synchronization signals used in

VGA (the main difference being, in VGA the horizontal and vertical syncs

are carried on different wires; whereas TLS signals include both H and V

syncs)

Waveform monitor: A waveform monitor is a special type of oscilloscope used

in television production applications. It is typically used to measure and display the

level, or voltage, of a video signal with respect to time.

The level of a video signal usually corresponds to the brightness, or luminance,

of the part of the image being drawn onto a regular video screen

at the same point in time. A waveform monitor can be used to display the overall

brightness of a television picture, or it can zoom in to show one or two individual

lines of the video signal. It can also be used to visualize and observe special signals

in the vertical blanking interval of a video signal, as well as the colorburst between

each line of video.

Procedure in recording

1. Set is designed in studio as per conceptual thought of program producer.

2. Lighting, Audio and placement of the cameras is arranged as per floor Plan.

3. Pre testing of cameras, microphones, VCRs etc. is done before recording.

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4. Recording begins and desired camera/mike are selected through VM/Audio

console as per command of producer. Program is recorded on VCR.

Procedure in Transmission

1. The programs are transmitted as per the daily cue sheet.

2. After getting D-link caption from Delhi end program is played from VCR/Server.

The program is uplinked by Earth Station.

3. During our slot, both live as well as recorded programs are transmitted.

Video Signal Generation Video is nothing but a sequence of pictures. The image we

see is maintained in our eye for 1/16th sec. So if we see images at the rate more than

16 pictures per second, our eyes cannot recognize the difference and we see the

continuous motion. In movie camera and Movie projector it is found that 24 fps

(frames per second) is better for human eyes. TV system could use this rate but in

PAL system 25 fps is selected. In TV cameras image is converted in electrical signal

using photosensitive material. Whole image is divided into many micro particles

known as pixels. These Pixels are small enough so that our eyes cannot recognize

pixels and we see continuous image. Thus ,at any particular instance there are almost

infinite numbers of pixels that need to be converted in electrical signal

simultaneously for transmitting picture detail . However this is not possible practical

because it is no feasible to provide a separate path for each pixel. In practice this

problem is solved by method known as scanning in which information is converted

one by one pixel. Line by line and frame by frame.

Basic Block Diagram of a TV studio chain

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Video Chain

The video we see at our home is either pre-recorded in the studio or live telecasted.

Block diagram illustrates different chains of video recording, video playback, news

and live broadcasting. In first chain we will understand studio program recording. In

first chain we will understand studio program recording. Camera output from the

studio hall is to CCU where many parameters of video signals are controlled. Output

signal of CCU after making all corrections is sent to VM in PCR-1 (production

control room). Output of 3 to 4 cameras comes here and final signal is selected here

using VM according to a director’s choice.

Typical Video and Audio Source Chain

Sources Vision

Mixer

LOGO

Generator

Earth station

through

Optical Fibre

Distributor

STL

Link

Sources Audio

Console Distributor

STL

Link

Earth station

through

Optical Fibre

Analog to AES

Convertor

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The final signal from VM is sent to VTR. VTR uses both analog and digital tape

recording system. At time transmitting this prerecord program cassettes is played in

to respective in VTR room .Signal from VTR is sent to PCR-2.PCR-2 has one VM,

video monitoring system, a CG (Computer graphics). From PCR-2, signal travels

from MSR to transmitter or earth station for terrestrial and satellite transmission.

MSR is the main control room between studio and transmitter or receiver.

Audio Chain In studio program, Audio from studio microphones is directly fed to

the AUDIO CONSOLE placed in PCR-1. It is used to mix the audio from different

sources and maintained its output. From AC, signal is directly recorded on tape with

video signal in VTR. While playing back audio is extracted from tape and fed to

another audio console placed in PCR-2 and then travels with the video signal.

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Schematic of Signal Transmission Through OB VAN and Studio

Synergy Video Switcher

- Complete control panel

- Serial digital inputs and output

- Full MLE effect systems

- Pattern generator which is used for wipe transitions

- Chroma keying

-12 untimed aux bus,each of which can be used to route video to monitor

-Clean feed features provides a second PGM output

- Display and indicators

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- Digital reference

- Downstream key facility

- Redundant power.

III.2 Electronic News Gathering

Electronic news-gathering (ENG) is a broadcast news industry description

of television producers, reporters and editors making use of electronic video and

audio technologies for gathering and presenting news. Recording and reporting

events and activities as they happen is what news is all about.

The various equipments used in ENG section are:

ENG Camera

Camcorder

VCR

Editing Booths

III.2.1ENG camera:The Electronic News Gathering (ENG) video camera

replaced 16mm motion-picture film for television news in the mid-1970s. The ENG

cameras are automated and fully operational within a few seconds after they are

switched on. You can make adjustments to extreme production situations quickly

and easily. Most ENG cameras weigh between six and 20pounds, depending

on the number of pickup tubes inside the camera. They are powered by batteries, but

you may also run them from AC current

using an adapter. Recording is to a

professional medium like some variant

of Betacam or DVCPRO or Direct to

disk recording or flash memory. If as in

the latter two, it's a data recording, much

higher data rates (or less video

compression) are used than in consumer devices.All settings, white balance, focus,

and iris can be manually adjusted, and automatics can be completely disabled.

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III.2.1.1. Parts of SONY Digital HD Video Camera RecorderNX5M

1. Hook for shoulder strap

2. ASSIGN /EXPANDED FOCUSbutton

3. Accessory shoe mount

4. Microphone fixing clamper

5. Microphone holder

6. Microphone

7. Accessory shoe

8. TC LINK switch

9. TC LINK IN/OUT jack

10. Zoom lever

1. Lens

2. Lens hood with lens cover

3. Internal microphone

4. The recording lamp flashes if theremaining capacity of recording media or

battery is low.

5. Remote sensor

6. ASSIGN 4/ZEBRA button

7. ASSIGN 5/AE SHIFT button* 8. ASSIGN 6/VISUAL INDEX button

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9. CH1 (INT MIC/INPUT1) switch

10. AUTO/MAN (CH1) switch

11. AUDIO LEVEL(CH1) dial

12. AUDIO LEVEL(CH2) dial

13. AUTO/MAN (CH2) switch

14. CH2 (INT MIC/INPUT1/INPUT2)switch

15. ASSIGN 1/2*/3 buttons

16. PUSH AUTO button

17. FOCUS switch

18. ND filter

1. VIDEO OUT jack/AUDIO OUT jacks

2. COMPONENT OUT jack

3. HDMI OUT jack

4. USB jack

5. SDI OUT jack

6. RELEASE lever

7. Handle zoom lever

8. Handle record button

9. INPUT2 jack

10. INPUT1 jack

11. Cable holder Provided for securing a microphonecable, etc.

12. INPUT2 switch

13. INPUT1 switch

14. REMOTE jack-The REMOTE jack is used for controlling playback, etc. on the video

device and peripherals connected to it.

15. Grip belt

16. POWER switch

17. Record button

18. Flash memory unit mount -For attaching a flash memory unit.

19. GPS switch (HXR-NX5E/NX5P)-When it is set to ON, the camcorder acquires the

GPS information (location and time of recording) and records with images.

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III.2.1.2.Camera Optics:

1. LENS

Focus Section

Zoom Section

Servo Drive Assembly

Aperture Section Drive

Back Foucs & Micro Focus

2. OPTICAL BLOCK

Color Filter Wheels

Prism & Dichroic Mirror

Bias light and a Suitable Lens Mount

3. TRANSDUCER OR PICK UP DEVICE

Types:

Photo emissive device

Photo conductive device

Charge coupled device

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4. CAMERA ELECTRONICS

III.2.2 Camcorder:A camcorder (formally a video camera recorder) is an electronic

device that combines a video camera and a video recorder into one unit; typically for

out-of-studio consumer video recordingIn older analog camcorders, the imaging

device was based on vacuum tube technology where the charge on a light sensitive

target was in direct proportion to the amount of light striking it. Newer analog and

all digital camcorders use a solid state Charge Coupled Device (CCD) imaging

device, or more recently a CMOS imager. Both of these latter devices use

photodiodes that pass a current proportional to the light striking them (i.e. they are

analog detectors), but that current is then digitised before being electronically

'scanned' before being fed to the imager's output. The principal difference in the

latter two devices is in the manner in which that 'scanning' is accomplished. In the

CCD, the diodes are all sampled simultaneously, and the scanning then achieved by

passing the digitised data from one register to the next (the Charge Coupled

element). In the CMOS device the diodes are sampled directly by the scanning logic.

III.2.3. VCR:The Video Cassette Recorder (or VCR, also known as the video

recorder) is an electro-mechanical device that records analog audio and analog

video from broadcast television on a removable, magnetic tape videocassette, so that

the images and sound can be played back at a more convenient time. This use of a

VCR is commonly referred to as television program Timeshifting.

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III.2.3.1. Parts of PANASONIC Digital Video Cassette Recorder AJ-965p

DVCPRO50

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Front Panel

1. Power swtich

2. Format Display Area

3. Remote Button

4. Super Switch

5. REC INH Switch

6. TCG Switch

7. MODE Switch

8. Cassette Insertion Slot

9. Eject Button

10. Play Button

11. REC Button

12. Stop Button

13. FF Button

14. REW Button

15. EDIT Button

16. STAND BY Button

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Rear Panel

1. AC IN socket

2. DIGITAL AUDIO IN and OUT connectors

3. ANALOG COMPONENT VIDEO IN connectors

4. ANALOG COMPOSITE VIDEO IN connectors

5. REF VIDEO IN connectors and 75 Ω termination switch

6. Remote control connectors

7. ENCODER REMOTE Connectors

8. ANALOG AUDIO IN connectors

9. TIME CODE IN connectors

10. TIME CODE OUT connectors

11. SERIAL COMPONENT AUDIO and VIDEO IN and OUT connectors

12. Fan

13. SIGNAL GND terminal

14. ANALOG COMPONENT VIDEO OUT connectors

15. ANALOG COMPOSITE VIDEO OUT connectors

16. RS-232c connectors

17. PARALLEL REMOTE connector

18. ANALOG AUDIO OUT connector

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19. MONITOR OUT connector

20. Option Connector

III.2.4. Editing booths: In ENG section Linear Editing takes place,Linear video

editing is a video editing post-production process of selecting, arranging and

modifying images and sound in a predetermined, orderedsequence. Regardless of

whether it was captured by a video camera, tapeless camcorder, or recorded in

a television studio on a video tape recorder(VTR) the content must be

accessed sequentially.

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III.3 Non-Linear Editing:

Non-linear editing enables direct access to any video frame in a digital video clip,

without needing to play or scrub/shuttle through adjacent footage to reach it, as was

necessary with historical video tape linear editing systems. It is now possible to

access any frame by entering directly the timecode or the descriptive metadata.

Video and audio data are first captured to hard disks, video server, or other digital

storage devices. The data are either direct to disk recording or are imported from

another source (transcoding,digitizing, transfer). Once imported, the source material

can be edited on a computer using application software, include fades, transitions,

and other effects that cannot be achieved with linear editing.

GRASS VALLEY EDIUS NLE :

It is a Linux based Server with NexSan Storage having 12 TB capacity and

havingCAT-5 LAN connection between all systems.It has Fiber Channel Connection

between storage and FC switch and also Fiber Connectivity between FC Switch,

Server & Edit-Workstations.

In Doordarshan Kendra Jalandhar, eight non-linear editing booths are in working

condition

Two kind of operating system are used in NLEs.

1. DPS Velocity (Windows - O.S.)

2. Adobe Premiere (Windows - O.S.)

3. Grass Valley Edius (Windows - O.S.)

4. Final Cut Pro (FCP) (MAC - O.S.)

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DPS Velocity HD: Real-Time:

HD/SD Non-Linear Editing System

Multi-Stream SD Editing

HD/SD Color Correction

Format Flexibility: 1080i, 1080PsF, 720p

Compressed or Uncompressed (8/10-bit)Video

On-Board SCSI for Dual Stream

FINAL CUT PRO:

64-bit architecture

Background rendering using GPU and CPU

Multi-stream real-time effects in SD and HD formats.

Supports 64-bit third-party Audio / Video plug-ins.

Audio sample rate up to 192kHz.

Adobe Premiere Pro:

Supports SD & HD Video formats for direct recording from Camera, Laptop

or Workstation.

High Quality Slow Motion.

GPU-accelerated effects to control frame rate, aspect ratio, field order, alpha

channels, pull-down removal, real-time keying, time remapping, transitions

etc.

News NLE:

Dedicated Velocity 8.2 for News Editing & Playback for Transmission.

Sharing with FTP client placed at News Room for importing Video clips

from News Stringers directly.

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III.4. Computer Section:The main objective of this section is the maintainence

of following machines based on computer technology:

1. Video Loggers

2. ENPS System

3. FTP Server

4. Win Plus & Auto Script Prompter

Video Loggers: The main function of video loggers is to record off-air programs

relayed by DD Punjabi. The video logger available at DDK Jalandhar is having 90

days recording and playback facility.

ENPS system:ENPS (Electronic News Production System) is a software application

developed by the Associated Press's Broadcast Technology division for producing,

editing, timing, organizing and running news broadcasts.

FTP Server: File Transfer Protocol (FTP) is a standard network protocol used to

transfer files from one host to another host over a TCP-based network, such as

the Internet. FTP may run in active or passive mode, which determines how the data

connection is established. In active mode, the client creates a TCP control

connection. In situations where the client is behind a firewall and unable to accept

incoming TCP connections, passive mode may be used. In this mode, the client uses

the control connection to send a PASV command to the server and then receives a

server IP address and server port number from the server, which the client then uses

to open a data connection from an arbitrary client port to the server IP address and

server port number received.

Autoscript Teleprompter:A teleprompter, or autocue, is a display device that

prompts the person speaking with an electronic visual text of a speech or script.

Using a teleprompter is similar to using cue cards. The screen is in front of, and

usually below, the lens of a professional video camera, and the words on the screen

are reflected to the eyes of the presenter using a sheet of clear glass or a specially

prepared beam splitter. Light from the performer passes through the front side of the

glass into the lens, while a shroud surrounding the lens and the back side of the glass

prevents unwanted light from entering the lens.

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Because the speaker does not need to look down to consult written notes, he appears

to have memorized the speech or to be speaking spontaneously, looking directly into

the camera lens. Cue cards, on the other hand, are always placed away from the lens

axis, making the speaker look at a point beside the camera, which leaves an

impression of distraction.

(1) Video camera

(2) Shroud

(3) Video monitor

(4) Clear glass or beam splitter

(5) Image from subject

(6) Image from video monitor

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III.5 Outdoor Broadcasting

Outside broadcasting (OB) is the electronic field production (EFP)

of television or radio programmes (typically to cover television news andsports

television events) from a mobile remote broadcast television studio. Professional

video camera and microphone signals come into theproduction truck for processing,

recording and possibly transmission. The mobile production control room (PCR) is

known as a OB van.

A typical OB van is usually divided into five parts:

Parts of the television crew are located in the first and largest part is the video

production area. The television director, technical director, assistant

director, character generator (CG) operator and television producers usually

sit in front of a wall of video monitors. The technical director sits in front of

the video switcher. The video monitors show all the video feeds from various

sources, including computer graphics, professional video cameras, video tape

recorder (VTR), video servers and slow-motion replay machines. The wall of

monitors also contains a preview monitor showing what could be the next

source on air and a program monitor that shows the feed currently going to

air or being recorded The video switcher is usually operated by one person

called the technical director (TD) and is responsible for switching the video

sources to air as directed. Behind the directors there is usually a desk with

monitors for the editors to operate. It is essential that the directors and editors

are in communication with each other during events, so that replays and

slow-motion shots can be selected and aired. The "production room" in most

sporting events has a graphics operator and sometimes a font coordinator who

are in charge of the graphics, statistics, and the showing of the names of

commentators or the players to be shown on air.

The second part of a van is where the audio engineer has an audio

mixer (being fed with all the various audio feeds: reporters, commentary, on-

field microphones, etc.). The audio engineer can control which channels are

added to the output and follows instructions from the director. They relay the

information from producers and directors to their A2's who typically set up

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the audio cables and equipment throughout the arenas and the booth where

the commentators sit. The audio engineer normally also has a dirty feed

monitor to help with the synchronization of sound and video.

The third part of the truck is the VTR area. The tape area has a collection of

machines including video servers and may also house additional power

supplies or computer equipment. The "tape room" hasLSM operators who

have one or more cameras that go into their machines and can be played back

for replays when an exciting or important play occurs during the game. LSM

operators also play replay rollouts that lead into commercial breaks or show

the highlights of the event at the end of play. These operators also can play

back in slow motion or pause to show a key part of the action.

The fourth part is the video control area where the professional video

cameras are controlled using camera control units (CCU) by one or

two operators, to make sure that the iris is at the correct exposure and that all

the cameras look the same. These operators can shade, balance, and focus the

cameras from this position inside the truck. This area is controlled by an

operator called a V1 and depending on the size of the show and/or the

broadcast company may have a V2.

The fifth part is transmission where the signal is monitored by and engineered

for quality control purposes and is transmitted or sent to other trucks. The

transmission is monitored by the truck engineers to ensure the people at home

have a good picture and a high quality signal output.

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III.6 EARTH STATION

The earth station is the link between the terrestrial data sources and the remote

satellite resource. Its most familiar component is the earth station antenna, which

can be tens of meters in diameter or a small portable dish. In addition, there are

numerous, less obvious devices in the chain of devices that transmit or receive the

signal. This article will briefly summarize some of the most important aspects of

earth station operation.

III.6.1 GeographicalPositionof Jalandhar

Longitude 75* 34’45” East

Latitude 31*19’32” North

III.6.2. Digital Earth Station:

Digital earth station is basically satellite up-linking station which is broadcasting in

digital mode. The satellite broadcasting has fully migrated from analog to digital

mode world wide. The satellite broadcasting was introduced in late eighties and was

begun with analog broadcasting. The analog video broadcasting occupies full 36

MHz transponder bandwidth for one video service. Doordarshan adopted Digital

Video Broadcasting -Satellite (DVB-S) in Simulcast Mode in the late nineties. In

simulcast mode, analog and digital services are transmitted simultaneously in the

same transponder bandwidth. 27MHz bandwidth was assigned to analog service

while 9 MHz to digital service. Simulcasting helped in smooth migration from

analog to digital. Now the satellite broadcasting is fully digitalized and is popularly

known as Digital Satellite News Gathering, Direct-to-Home, Digital Earth Station.

All major Doordarshan Kendras have Digital Earth Stations which are up-linking one

regional and one national service. 9MHz bandwidth is allotted to each Kendra. Four

Kendra’s are therefore sharing 36MHz bandwidth of a transponder.

At the beginning of nineties, Digital Video Broadcasting (DVB) was created as a

European project. In the course of this project, three transmission methods were

developed: DVB-S (Satellite), DVB-C (cable) and DVB-T (Terrestrial). The satellite

transmission method DVB-S has been in use since about 1995. DVB-S specifies

Quadrature Phase Shift Keying (QPSK) as digital modulation. 8PSK is also

incorporated in DVB-DSNG version of satellite transmission standards.

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Digital Communication setup

III.6.2. Play Back Booth: In play back booth the main purpose is to play the

live programs e.g. the let us take an example of a live program in which we need to

play the songs on the demand of the consumers the all the songs in the list first to be

dumped on a machine , then to be played on demand. Studio connectivity has been

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provided through OFC via central apparatus room. However coaxial cables has also

been provided as standby to OFCCommand/Communication with studios, CAR and

VTR room etc. has also been provided.

Main Equipment of play back

Router ,make Seiravedio system

DVC (DVC PRO 50,make Panasonic)

BTS ,make sony, Betacam sp,2800P

SERVER ,make Leitch

VISTEK FRAME

(EMD,DEMD,ADC)

CG (MOVE CG PRO)

III.6.3. Power Supply Distribution at Earth Station

Fig: Block Diagram

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Fig: Implementation

BASEBAND RACK:

Fiber optic receiver to receive embedded signal

from studio(CAR)

Signal generator

Audio level monitor

Video monitor

COMPRESSION RACK:

Encoders

Multiplexers

Modulators

Redundancy switch

NMS

Rx Monitoring Rack

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UP convertor

RF power divider

C to L band Convertor

I.R.D

Spectrum Analyzer

HPA Rack

HPA

Dehydrator

Waveguide

Earth Station classification

Analog Earth Station

Digital Earth Station

ASNG

DSNG

C-band or Ku-band

Problems of Analog

One program per channel/transponder

Comparatively noisy

Ghosts in Terrestrial Transmission

Lower quality with respect to VCD, DVD digital medium‡

Fixed reception

Advantages of digital over analog

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More programs per channel/Transponder i.e. spectrum efficient.

Noise-Free Reception.

Ghost elimination.

CD quality sound & better than DVD quality picture.

Reduced transmission power.

Flexibility in service planning.

Process involved in transmission of signal

Up-Conversion

High power amplification

Transmission

Reception Up-Converters

The up-conversion is required to raise the frequency of the signal in desired band: C- band,

Extended C-band or Ku-band before transmission. The input to up converter is 70 MHz

(output of modulator) and output of Up-converter is fed to HPA.The up-conversion may be

done in stages or in one stage directly. The 70 MHz signal is first converted into L ±band and

then L band signal raised to desired frequency band.

High power amplification

The high power amplifier is used for the final power amplification of the digital RF signal in C-

band/Ku band that is fed to the antenna. The important parameters of HPAs are:

Frequency range

Output power at flange

Bandwidth

Gain variation (1.0db (max.) for 40 MHz (narrow band)

2.50db for full bandwidth.

The different types of HPAs are

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KHPA - Klystron High Power Amplifier

TWTA -Traveling Wave Tube Amplifier

SSPA- Solid state Power Amplifier

III.7. TRANSMITTER

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A television transmitter is a device which broadcasts an electromagnetic signal to

the television receivers. Television transmitters may be analog or digital.

Transmitter station refers to terrestrial infrastructure for transmitting radioa frequency

signals. The station maybe used for wireless communication, broadcasting, microwave

link, mobile telephone or other purposes.

Terrestrial transmission: A transmission from point A to point B that doesn’t make use of

satellites.

If the transmission is straight from point A to point B, then the maximize range it's a bit more

of the horizon (depending on what frequency are you transmitting)

Use of repeaters can extend the range.

LF MF HF VHF UHF are the most common frequencies used for terrestrial communications.

III.7.1. Broadcast Transmitter

A broadcast transmitter refers to an installation used for broadcasting, including radio

transmitter or television transmitter equipment, the antenna, and often the location of the

broadcasting station. It has following parts:

1. Exciter

2. Power Supply

3. Frequency Control

4. Cooling of final Stages

5. Protection Equipment

III.7.1.1 Exciter

In broadcasting and telecommunication, the part which contains the oscillator, modulator, and

sometimes audio processor, is called the "exciter". Most transmitters use heterodyne principle,

so they also have a frequency conversion units. Confusingly, the high-power amplifier which the

exciter then feeds into is often called the "transmitter" by broadcast engineers. The final output is

given as transmitter power output (TPO).

III.7.1.2 Power Supply

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Transmitters are sometimes fed from a higher voltage level of the power supply grid than

necessary in order to improve security of supply. For example,

the Allouis, Konstantynowand Roumoules transmitters are fed from the high-voltage network

(110 kV in Alouis and Konstantynow, 150 kV in Roumoules) even though a power supply from

the medium-voltage level of the power grid (about 20 kV) would be able to deliver enough power.

III.7.1.3 Cooling of final Stages

Low-power transmitters do not require special cooling equipment. Modern transmitters can be

incredibly efficient, with efficiencies exceeding 98 percent. However, a broadcast transmitter with

a megawatt power stage transferring 98% of that into the antenna can also be viewed as a 20

kilowatt electric heater.

For medium-power transmitters, up to a few hundred watts, air cooling with fans is used. At

power levels over a few kilowatts, the output stage is cooled by a forced liquid cooling system

analogous to an automobile cooling system. Since the coolant directly touches the high-

voltage anodes of the tubes, only distilled, deionised water or a special dielectric coolant can be

used in the cooling circuit. This high-purity coolant is in turn cooled by a heat exchanger, where

the second cooling circuit can use water of ordinary quality because it is not in contact with

energized parts.

III.7.1.4 Protective Equipment

The high voltages used in high power transmitters (up to 40 kV) require extensive protection

equipment. Also, transmitters are exposed to damage from lightning. Transmitters may be

damaged if operated without an antenna, so protection circuits must detect the loss of the

antenna and switch off the transmitter immediately.

Lightning protection is required between the transmitter and antenna. This consists of spark

gaps and gas-filled surge arresters to limit the voltage that appears on the transmitter terminals.

In some transmitting plants UV detectors are fitted in critical places, to switch off the transmitter if

an arc is detected.

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Fig:DD1 Exciter

Fig:DD2 Exciter

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III.7.2 Analog transmission

Analog (or analogue) transmission is a transmission method of conveying voice, data, image,

signal or video information using a continuous signal which varies in amplitude, phase, or

some other property in proportion to that of a variable. It could be the transfer of an analog

source signal, using an analog modulation method such as frequency modulation (FM)

or amplitude modulation (AM), or no modulation at all.

III.7.3 Digital transmission

Data transmission, digital transmission, or digital communications is the physical transfer

of data (a digital bit stream) over a point-to-point or point-to-multipoint

communication channel. Examples of such channels are copper wires, optical

fibres, wireless communication channels, storage media and computer buses. The data are

represented as an electromagnetic signal, such as an electrical

voltage, radiowave, microwave, or infrared signal. While analog transmission is the transfer

of a continuously varying analog signal, digital communications is the transfer of discrete

messages.

III.7.4 Transmission

DTTV is transmitted on radio frequencies through terrestrial space in the same way as

standard analog television, with the primary difference being the use of multiplextransmitters

to allow reception of multiple channels on a single frequency range (such as

a UHF or VHF channel) known as subchannels.

The amount of data that can be transmitted (and therefore the number of channels) is directly

affected by channel capacity and the modulation method of the channel. The modulation

method in DVB-T is COFDM with either 64 or 16-state Quadrature Amplitude

Modulation (QAM). In general, a 64QAM channel is capable of transmitting a greater bit

rate, but is more susceptible to interference.

III.7.5 Reception

DTTV is received either via a digital set-top box (STB) or integrated tuner included

with television sets, that decodes the signal received via a standard television antenna. Some

set-top-boxes include digital video recorder (DVR) functionality.

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III.7.6 Basic functioning of Transmitter at Jalandhar

The transmitter tower at Jalandhar currently operates on analog transmission. There are two

transmitters one is VHF and other is UHF. The VHF transmitter is CH#9 used for

transmission is DD NATIONAL channel while the UHF is CH#22 used for telecasting DD

NEWS. Both are of 10kW power.

After receiving the signals of these two channels through satellite, the signals undergo certain

processes. Firstly, audio and video components are separated and fed into exciter. The audio

component is amplified using FM technique and video component is amplified using AM

technique. The signal is amplied using power amplifiers of lower power then combined to

give a amplified signal. This amplified audio and video signal is then passed two the wave

guides. Wave guide is made of copper to reduce the distortions in signal. Then both amplified

audio and video components are recombined maintaining a band difference of 55.5 MHz and

then it is transmitted to the top of tower for telecasting.

III.7.7. Picture Basics :-A television creates a continuous series of moving

pictures on the screen. This sectionwill describe in detail how pictures are created in

a television. A camera works exactly on the same principleapplied the other way

round. A picture is "drawn" on a television or computer display screen by sweeping

an electrical signal horizontally across the display one line at a time. The amplitude

of this signal versus time represents the instantaneous brightness at that physical

point on the display. At the end of each line, there is a portion of the waveform

(horizontal blanking interval) that tells the scanning circuit in the display to retrace to

the left edge of the display and then start scanning the next line. Starting at the top,

all of the lines on the display are scanned in this way. One complete set of lines

makes a picture. This is called a frame. Once

thefirstcomplete picture is scanned, there is another portion of the waveform (vertical

blanking interval, not shown) that tells the scanning circuit to retrace to

thetop of the display and start scanning the next frame, or picture. Thissequence is

repeated at a fast enough rate so that the displayed images are perceived to have

continuous motion. This is the same principle as that behind the "flip books" that you

rapidly flip through to see a moving picture or cartoons that are drawn and rapidly

displayed one picture at a time. Interlaced versus Progressive

ScansThesearetwodifferenttypesof systems.

They differinthetechnique used to cover the area of the screen. Television signals and

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compatible displays are typically interlaced, and computer signals and compatible

displays are typically progressive (non-interlaced). These two formats are

incompatible with each other; one would need to be converted to the other before any

common processing could be done. Interlaced scanning is where each picture,

referred to as a frame, is divided into two separate sub-pictures, and referred to as

fields. Two fields make up a frame. An interlaced picture is painted on the screen

in two passes, by first scanning the horizontal lines of the first field and then

retracing to the top of the screen and then scanning the horizontal lines for the

second field in-between the first set. Field 1 consists of lines 1 through 262 1/2, and

field 2 consists of lines 262 ½ through 525. The interlaced principle

is illustrated in Figure2. Only a few lines at the top and the bottom of each field are

shown.

here are many different kinds of video signals, which can be divided into either

television or computer types. The format of television signals varies from country to

country. In the United States and Japan, the NTSC format is used. NTSC stands

for National Television Systems Committee, which is the name of the organization

that developed the standard. In Europe, the PAL format is common. PAL (phase

alternating line), developed after NTSC, is an improvement over NTSC. SECAM is

used in France and stands for sequential coleur avec memoire (with memory). It

should be noted that there is atotal of about 15 different sub-formats contained within

these three general formats. Each of the formats is generally not compatible with

theothers. Although they all utilize the same basic scanning system andrepresent

color with a type of phase modulation, they differ in

specificscanning frequencies, number of scan lines, and color modulation

techniques, among others. The various computer formats (such as VGA,XGA, and

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UXGA) also differ substantially, with the primary difference

inthe scan frequencies. These differences do not cause a s mu ch con ce rn , becaus

e most computer equipment is now designed to handle variable scan rates. This

compatibility is a major advantage for computer formats in that

media, and content can be interchanged on a global basis.

In India we use the PAL system. It has 625 lines in each frame and uses interlaced

scanning

There are three basic levels of baseband signal interfaces. In order of increasing

quality, they are composite (or CVBS), which uses one wire pair; Y/C (or S-video),

whichuses two wire pairs; and component, which uses three wire pairs. Each wire

pair consists of a signal and a ground.

Thesethree interfaces differ in their level of information combination. More encoding

typically degrades the quality but allows the signal to be carried on fewerwires.

Component has the least amount of encoding, and composite the most.

VideoFormat NTSC PAL HDTV/SDTV

Description TelevisionFormat

forNorthAmerica

andJapan

TelevisionFormat

forMost of Europe and

South America.Used in

India

High

Definition/StandardDefinition

DigitalTelevision Format

VerticalResolutionFormat

(visiblelines per frame)

Approx 480(525

totallines)

Approx 575(625 total

lines)

1080 or 720 or 480;18

different formats

HorizontalResolution

Format(visible pixels per

line)

Determined

by bandwidth,ranges

from320 to 650

Determined

by bandwidth,ranges

from320 to 720

1920 or 704 or 640;18

different formats

HorizontalRate

(kHz)

15.734 15.625 33.75-45

Vertical FrameRate

(Hz)

29.97 25 30-60

HighestFrequency

(MHz)

4.2 5.5 25

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Composite/CVBS Interface

Composite signals are the most commonly used analog video interface.Composite vi

deo is also

referred to as CVBS, which stands for color,video, blanking, and sync, orcomposite

video

baseband signal. Itcombines the brightness information (luma), the color information

( chroma ), and the synchronizing signals on just one cable. The connector is

typically an RCA jack. This is the same connector as that used for

standardline level audio connections.

It is possible to obtain any desired colour by mixing three primarycolours i.e., red,

blue and green in suitable proportion.

The figure 10 shows the effect of projecting red, green, blue beams of light so that

they overlapon screen.Y = 0 . 3 R e d + 0 . 5 9 G r e e n + 0 . 1 1 B l u e

The Colour Television

Thus it isonly required to convert optical information of these three coloursto

electrical signals and transmit it on different carriers to bedecoded by the

receiver. This can then be converted back to theoptical image at the picture

tube. The phosphors for all the threecolours i.e. R, G and B are easily available to the

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manufacturers of the picture tube. So the pick up from the cameras and output forthe

picture tube should consists of three signals i.e. R, G and B. Itis only in between the

camera and the picture tube of the receiverwe need a system to transmit this

information.Colour television has the constraint of compatibility and

reversecompatibility with the monochrome television system whichmakes

it slightly complicated. Compatibility means that whencolour TV signal is radiated

the monochrome TV sets should alsodisplay Black & White pictures. This

is achieved by sending Y asmonochrome information along with

the chroma signal. Y isobtained by mixing R,G & B as per the well known equation :

Y= 0 . 3 R + 0 .59 G + 0.11 BReverse compatibility means that when Black &

White TV signal

isradiated the colour TV sets should display the Black & Whitepictures

Some important terms and their meanings in this context are listed below:

Aspect Ratio

Aspect ratio is the ratio of the visible-picture width to the height. Standard

television andcomputers have an aspect ratio of 4:3(1.33). H D T V h as aspects

ratios of either 4:3 or 16:9(1.78). Additional aspect ratios like 1.85:1or 2.35:1 are

used in cinema.

Banking intervals

There are horizontal and vertical blanking intervals. Horizontal blanking interval is

the time period allocated for retrace of the signal from the right edge of the display

back to the left edge to start another scan line. Vertical blanking interval is the time

period allocated for retrace of the signal from the bottom back to the top to start

another field or frame. Synchronizingsignals occupy a portion of the blanking

interval.

Blanking Level

Used to describe a voltage level (blanking level). The blanking level is thenominal

voltage of a video waveform during the horizontal and vertical periods, excluding the

more negative voltage sync tips

.

Chroma

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The color portion of a video signal. This term is sometimes

incorrectlyreferred to as "chrominance," which is the actual displayed color informat

ion.

Color Burst

The color burst, also commonly called the "color subcarrier," is 8 to 10cycles of the

color reference frequency. It is positioned between the risingedge of sync and

the start of active video for a composite video signal.

Fields and Frames

A frame is one complete scan of a picture. In NTSC it consists of 5 2 5 horizontal

scan lines. In interlaced scanning systems, a field is half of aframe; thus, two fields

make a frame.

Luma

The monochrome or black-and-white portion of a video signal. This term is

sometimes incorrectly called "luminance," which refers to the actualdisplayed

brightness.

Monochrome

The luma (brightness) portion of a video signal without the c o l o r information.

Monochrome, commonly known as black-and-white, predatescurrent color

television.

PAL

Phase alternate line. PAL is used to refer to systems and signals that are compatible

with this specific modulation technique. Similar to NTSC butuses subcarrier phase

alternation to reduce the sensitivity to phase errors thatwould be displayed as color

errors. Commonly used with 626-line, 50Hzscanning systems with a subcarrier

frequency of 4.43362MHz.

Pixel

Picture element. A pixel is the smallest piece of display detail that has aunique

brightness and color. In a digital image, a pixel is an individual

pointin the image, represented by a certain number of bits to indicate the brightness.

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RGB

Stands for red, green, and blue. It is a component interface typically used incomputer

graphics systems.Sync Signals/PulsesSync signals, also known as sync pulses, are

negative-going timing pulses invideo signals that are used by video-

processing or display devices tosynchronize the horizontal and vertical portions of

the display.

Y Cr Cb

A digital component video interface. Y is the luma (brightness) portion, andCr and

Cb are the color-difference portions of the signal.

Y/C

An analog video interface in which the chroma (color) information is

carriedseparately from the luma (brightness) and sync information. Two wire

pairsare used, denoted Y and C or Y/C. Often incorrectly referred to as "S-video.

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IV. Industry Applications

1. Doordarshan has a three tier programme service – National, Regional and

Local.

2. The emphasis in the National programmes is on events and issues of interest

to the entire nation.

3. These programmes include news and current affairs, magazine programmes

and documentaries on science, art and culture, environment, social issues,

serials, music, dance, drama and feature films.

4. The regional programmes are beamed on DD National at specific times and

also on the Regional Language Satellite Channels, catering to the interests of

a particular state, in the language and idiom of that region.

5. The local programmes are area specific and cover local issues featuring local

people.

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V. Future Enhancements

Doordarshan has completed its objective of providing information related to

the every field of daily life to the common man time to time. Whether

Doordarshan kendra Jalandhar is having analog transmission till now. But,

with the each passing day it is moving towards the betterment whether in the

form of digitiztion or in the form of stepping towards HDTV from SDTV.

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VI. Conclusions

The technology currently in use at Prasar Bharati has improved significantly. At this stage

there has been advancement in signal reception quality as systems are changing from

analog to digital with the advancement in different audio and video compression

techniques. For Doordarshan, DTH (Direct To Home Service) satellite services have

become more user friendly and also evolution of SDTV into HDTV have made it a popular

product among the people of India. It is also accessible from remote areas with more

channel and better reception.

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VII. Bibliography

1. http://en.wikipedia.org/wiki/

2. http://prasarbharati.gov.in/

3. Antennas & Propagation,CS 6710, Spring 2010, Rajmohan Rajaraman

4. Electromagnetic Radiations and antennas, whites EE 382

5. Transmission Techniques for Digital Terrestrial TV Broadcasting By

Hikmet Sari, Georges Karan and Issabelle Jeanclaude