A SIMENAR PRESENTATION ONDOORDARSHAN “PRASAR

BHARTI”

PRESENTED BY :

Ashraful HodaAshraful.hoda01@mail.

com

DOORDARSHANDoordarshan = Distant + Show.

Doordarshan is an Indian public service broadcaster.

 One of the largest broadcasting organizations in India in terms of the infrastructure of studios and transmitters.  According to Pioneer Investors, the Indian cable industry is worth 270 billion and is the third largest in the world after China and United States.

HISTORYBroadcasting started in India in the year 1923.

AIR was formed in the year 1936.

In 1947, AIR was covering 2.5% & about 11% of land & population respectively.

1st T.V Station was established in Delhi in 1959

T.V was separated from AIR in 1976

INTRODUCTION•Broadcasting :A process of sending information to a distant place is called Broadcasting.•Means of Broadcasting in India:1. Terrestrial 2. Satellite3. Internet•Both AIR & DD make use of both Terrestrial & satellite.

TV STUDIO A television studio is an installation in which television or video productions take place.

COMPONENTS OF TV STUDIO• Camera• Lighting• Microphones• Vision mixer and Audio consoles• MSR• VTR• Acoustics• Post production and video effects• Supporting services like AC, UPS

VISION MIXER• A vision mixer is a device used to

select between several different video sources and in some cases mix video sources together and add special effects.• It has many input sources such as

cameras, VCR/ server, Graphics/Character Generators, etc.• Out of these i/p, any source can be

taken as o/p.• Sources can be changed as cut to

cut, dissolve, wipe and other special effects.

TYPICAL VIDEO CHAINSOURC

E

VISION MIXTE

R

LOGO GENERATE

R

DISTRIBUTER

EARTH STATION

THROUGH OPTICAL

FIBOR

STL LINK

TYPICAL AUDIO CHAIN

SOURCE

AUDIO CONSOL

DISTRIBUTER

ANALOG TO AES

CONVRTER

STL LINK

EARTH STATION

THROUGH OPTICAL

FIBOR

MSR (MASTER SWITCHING ROOM)•It is the heart of the studio.•Most of the switching electronics is kept e.g. camera base stations, switcher main frame, SPG, Satellite receivers, MW link, DDA & most of the patch panels.•Signal is routed through MSR.•Signal can be Monitored at various stages

EARTH STATION• Earth Station is a very important part of

satellite communication system for broadcasting of signals. • It is an uplink center from which the signals

are fed to Satellite for distribution in a specified area covered by the Satellite.• The signal is up-linked from the Earth Station

and received by many down link centers in TV broad casting via PDA(Parabolic Dish Antenna).• Two Types:

1) Analog2)Digital• Digital earth station are wildly used of

various advantage over analog.

MAJOR COMPONENTS OF EARTH STATION• PDA (Parabolic Dish

Antenna)• FEED• Wave Guide / Low Loss

Cable• HPA (TWTA, Klystrons)• Up converter• Modulator• Encoder• Multiplexer• IRD (Integrated Receiver

Decoder)

TYPES OF TV TRANSMITTERVLPT : Very Low Power Transmitter•10w-50w•Used for small coverage areas.LPT : Low Power Transmitter•100w-500w•Used for relatively large areas.HPT : High Power Transmitter•More than 1kw•Used for larger areas.

ANTENNAS & SATELLITES•An antenna (or aerial) is a transducer designed to transmit or receive electromagnetic waves. In other words, antennas convert electromagnetic waves into electrical currents and vice versa.

Transmitting Antenna

Receiving Antenna

Electrical signal Electro Magnetic Wave

TYPES OF ANTENNAIsotropic antenna (idealized)•Radiates power equally in all directions.Dipole antennas-•Half-wave dipole antenna (or Hertz antenna)•Quarter-wave vertical antenna (or Marconi antenna)Parabolic Dish / Reflective Antenna

OB VANA typical Outside Broadcasting Van is

usually divided into 4 parts:

• The first and largest part is the production area or sitting area for all directors & producers.• The second part of a van is for the audio

engineer.• The 3rd part of the van is video tape • The 4th part is transmission where the

signal is monitored by and engineered for quality control purposes and is transmitted or sent to other trucks.

INTERNAL STRUCTURE OF OB VAN

DNSG•This is known as direct satellite news gathering.•It works simultaneously with OB van.•Its also called as mobile earth station.•The dish can be aligned acc to the requirement.•Monitors are available in this van to check the telecast.•High power ups are also available in this van.

THANKS