Doordarshan mumbai ppt on television broadcasting and transmissionRahulBagal4
The presentation is based on the internship that i did in doordarshan,mumbai during the traning period i have learned a lot about their process of transmission,broadcasting and transmission.
This document is Satyendra Gupta's summer industrial training report on his training at Doordarshan Kendra Lucknow. It provides an overview of Doordarshan Lucknow and describes the key divisions of Studio, Transmitter, and Earth Station. It also covers the fundamentals of monochrome and color television systems as well as concepts like the color composite video signal, television cameras, lighting, microphones, video tape recording, vision mixing, 3D graphics, transmission, antennas, outdoor broadcasting vans, and direct-to-home satellite broadcasting.
This document provides information about Doordarshan, the national public service broadcaster of India. It discusses the origin and development of Doordarshan from its beginnings in 1959 as a small studio to becoming one of the largest broadcast organizations in the world today. It also describes the technical processes and components involved in terrestrial television transmission using Doordarshan transmitters, including visual and audio signal chains, vestigial sideband transmission, and features of high power transmitters.
This document discusses various broadcasting and video systems. It covers AM broadcasting which uses frequency bands and carrier spacing to avoid signal overlap. It also discusses FM broadcasting which uses frequency division multiplexing to transmit stereo sound. The document also covers black and white television which uses raster scanning to transmit video as a serial data stream, and color television techniques like PAL and NTSC which encode color images and multiplex color signals for transmission.
Doordarshan is the oldest and the biggest Broadcasting media in India.. One must have never thought that so many things are required for watching a television. The camera, the studio, the transmitter, the PDA, the setup box (installed in houses) everything is connected to each other. Here man and electronics work as if they are a family. So many process and lots of hard work, sincerity is required to just have a show or say a movie on air i.e. to be broadcasted.
This document provides an overview of key concepts in communications systems, including:
1) It describes the basic components of a communications system including the input/output transducers, transmitter, channel, and receiver.
2) It discusses different types of signals that can be transmitted through a channel including analog modulation techniques like AM, FM and PM as well as digital modulation.
3) It provides an overview of electromagnetic waves and the electromagnetic spectrum used for wireless communication.
This document is Amal Roshan's summer training report submitted to NIT Calicut. It includes declarations and certificates signed by Amal Roshan and his guide, as well as sections on:
- The history of Doordarshan and Doordarshan Patna, where Amal did his summer training.
- Fundamentals of monochrome and colour TV systems, including picture formation, scanning, and interlacing.
- Details of the studio setup and coverage at Doordarshan Patna, including cameras, transmitters, and facilities.
There are many types of wireless channel impairments such as noise, path loss, shadowing, and fading and impairment Mitigation techniques should be adopted according to system requirements and channel environments.
Doordarshan mumbai ppt on television broadcasting and transmissionRahulBagal4
The presentation is based on the internship that i did in doordarshan,mumbai during the traning period i have learned a lot about their process of transmission,broadcasting and transmission.
This document is Satyendra Gupta's summer industrial training report on his training at Doordarshan Kendra Lucknow. It provides an overview of Doordarshan Lucknow and describes the key divisions of Studio, Transmitter, and Earth Station. It also covers the fundamentals of monochrome and color television systems as well as concepts like the color composite video signal, television cameras, lighting, microphones, video tape recording, vision mixing, 3D graphics, transmission, antennas, outdoor broadcasting vans, and direct-to-home satellite broadcasting.
This document provides information about Doordarshan, the national public service broadcaster of India. It discusses the origin and development of Doordarshan from its beginnings in 1959 as a small studio to becoming one of the largest broadcast organizations in the world today. It also describes the technical processes and components involved in terrestrial television transmission using Doordarshan transmitters, including visual and audio signal chains, vestigial sideband transmission, and features of high power transmitters.
This document discusses various broadcasting and video systems. It covers AM broadcasting which uses frequency bands and carrier spacing to avoid signal overlap. It also discusses FM broadcasting which uses frequency division multiplexing to transmit stereo sound. The document also covers black and white television which uses raster scanning to transmit video as a serial data stream, and color television techniques like PAL and NTSC which encode color images and multiplex color signals for transmission.
Doordarshan is the oldest and the biggest Broadcasting media in India.. One must have never thought that so many things are required for watching a television. The camera, the studio, the transmitter, the PDA, the setup box (installed in houses) everything is connected to each other. Here man and electronics work as if they are a family. So many process and lots of hard work, sincerity is required to just have a show or say a movie on air i.e. to be broadcasted.
This document provides an overview of key concepts in communications systems, including:
1) It describes the basic components of a communications system including the input/output transducers, transmitter, channel, and receiver.
2) It discusses different types of signals that can be transmitted through a channel including analog modulation techniques like AM, FM and PM as well as digital modulation.
3) It provides an overview of electromagnetic waves and the electromagnetic spectrum used for wireless communication.
This document is Amal Roshan's summer training report submitted to NIT Calicut. It includes declarations and certificates signed by Amal Roshan and his guide, as well as sections on:
- The history of Doordarshan and Doordarshan Patna, where Amal did his summer training.
- Fundamentals of monochrome and colour TV systems, including picture formation, scanning, and interlacing.
- Details of the studio setup and coverage at Doordarshan Patna, including cameras, transmitters, and facilities.
There are many types of wireless channel impairments such as noise, path loss, shadowing, and fading and impairment Mitigation techniques should be adopted according to system requirements and channel environments.
This document provides an overview of Doordarshan Kendra's industrial training on television broadcast systems. It discusses Doordarshan as India's public service broadcaster, established in 1959. It then focuses on Jammu Kendra, describing its location, studios, transmitter section, and satellite usage. The document covers fundamentals of television like picture formation, resolution, color, and standards. It describes the key components of a television studio and transmission setup, including lighting, cameras, microphones, sync pulse generators, and vestigial sideband transmission. Modes of transmission like satellite communication and microwave are also summarized.
Industrial Training Report at DDK Mandi House New Delhirajeevkr35
The document provides information about Rajeev Kumar's internship at Doordarshan Kendra in New Delhi. It includes an acknowledgement section thanking those who helped and guided him. The preface discusses how the internship helped develop his professional skills and gain real industry experience. It also provided an opportunity to learn new technologies. The certificate section confirms Rajeev successfully completed his internship under the guidance of Mr. Gurjeet Singh and Amita Gautam at Doordarshan Kendra from June 20th to July 15th 2016.
The document provides details about Sushant Shankar's 4-week summer training program at Doordarshan Lucknow under the guidance of Mr. R. Naithani. It includes a declaration signed by Sushant that the work is original. It also includes a certificate signed by Mr. Naithani confirming that Sushant completed the training program. The document then acknowledges and thanks various people who helped and supported Sushant during the training.
This document provides information about Doordarshan Kendra in Raipur. It discusses Doordarshan's headquarters and staff in Raipur. It describes the various programs and services provided by Doordarshan such as awareness, education, and entertainment programs. It then provides details about the components of a television studio including cameras, lighting, audio equipment, and vision mixing. Additional sections describe the earth station, transmission center, antennas, outside broadcasting vans, and Doordarshan's setup in Raipur.
This document discusses various techniques used to improve mobile radio link performance including equalization, diversity, and channel coding. It describes equalization techniques that compensate for intersymbol interference caused by multipath. It explains different types of diversity including spatial, time, and frequency diversity that are used to mitigate fading. Specifically, it outlines four common spatial diversity techniques: selection diversity, maximal ratio combining, equal gain diversity, and scanning diversity. The document also discusses time diversity and RAKE receivers used in code division multiple access systems to exploit multipath for additional time diversity gain.
The document defines communication and its basic elements, which are a transmitter, channel, and receiver. It describes transmission media as the pathway that carries information between sender and receiver. The two main types are wired/guided media and wireless/unguided media. It also discusses analog and digital signals, periodic vs aperiodic signals, baseband vs broadband transmission, noise and signal-to-noise ratio, multiplexing, and provides short notes on communication through the ionosphere and DSB-SC and VSB modulation techniques.
ppt Or report of training on doordarshan TV broadcasting Siraj Ahmed
The document provides an overview of broadcasting at Doordarshan Kendra in Silchar, India. It discusses the key components of a Doordarshan studio including the studio itself, lighting, acoustic systems, cameras, and transmitter. It also describes the earth station that is used to send program signals to satellites for transmission and reception, and outlines the basic process of transmission from uplinking to satellites to downlinking to receivers.
Small-scale fading in wireless channels is caused by multipath propagation. There are three main effects: rapid signal strength changes over small distances/times, random Doppler shifts from multipath signals, and time dispersion of echoes. Multipath results from reflection, diffraction and scattering off surroundings. Several methods measure multipath structure including direct RF pulse systems, spread spectrum sliding correlators, and frequency domain channel sounding using vector network analyzers. These techniques help determine power delay profiles and understand time-varying multipath effects.
The document provides information about a communications systems course, including:
- The lecturer's contact information and grading breakdown
- An outline of the topics to be covered in each of the 16 weeks including transmission media, wireless communication, and mobile networks
- Expectations that students can interrupt with questions, should try to solve problems themselves before asking for help, and should review notes after class
- An index of subtopics to be discussed like historical background, communication system components, analog and digital systems, and important communication systems.
This document provides an overview of Doordarshan High Power Transmitter in Kanpur, including:
1. It discusses the history and components of Doordarshan, including TV studios, vision mixers, earth stations, and OB Vans.
2. While Doordarshan was an important part of electronic media in India, it is now losing viewers due to a lack of engaging content for youth and not adapting to changing market trends.
3. Suggestions are provided to help Doordarshan modernize and better utilize its resources, such as promoting content on social media and allowing more creative freedom.
This chapter discusses small-scale fading and multipath propagation effects in mobile radio channels. It explains that multipath waves traveling along paths of different lengths interfere at the receiver, causing rapid fluctuations in signal strength over short distances. The key points are:
1) Small-scale fading is caused by multipath interference and depends on factors like surrounding objects, signal bandwidth, and mobile speed.
2) Multipath propagation can be modeled using the time-varying impulse response of the channel.
3) Important parameters used to characterize fading include coherence bandwidth, Doppler spread, coherence time, delay spread, and Ricean/Rayleigh distributions.
The process of communication and Basic Block Diagram of Communication system is presented in this PPT.
The various Blocks like Information Source, Transmitter, Communication Channel, Noise, Receiver and Destination Blocks are discussed in detail
Doordarshan is India's public service broadcaster and one of the largest in India in terms of studio and transmitter infrastructure. It began broadcasting in 1959 and has grown to include 1500 transmitters and 70 production centers across the country. The document discusses the components and functions of a television studio, including cameras, lighting, microphones, vision mixers, audio consoles, and more. It also describes the earth station, which is crucial for broadcasting signals via satellite, and details the parameters of Raipur's earth station. Finally, it discusses television transmitters and the different types (VLPT, LPT, HPT), noting that Raipur's 10 kW HPT can cover an area of 90-110 km.
This document discusses telephone systems and multiplexing. It describes how telephone networks use circuit switching and have evolved from analog to digital systems. The basic telephone network consists of local loops connecting subscribers to switching offices, trunks connecting the offices, and switches establishing connections. Multiplexing allows transmitting multiple signals over one channel by combining them. Types of multiplexing include FDM, WDM, and TDM. FDM uses separate carrier frequencies. WDM uses different wavelengths of light. TDM transmits signals in sequential time slots. Multiplexing increases channel capacity.
This document provides an introduction to communication systems, including why modulation is needed, the basic components of transmitters and receivers, and different multiplexing techniques. It discusses how modulation converts information to radio frequencies for transmission, and how receivers convert the signals back down for processing. It also outlines several multiple access techniques used in cellular systems, including FDMA, TDMA, and CDMA, and provides block diagrams of cellular phone components.
ECE 618 covers topics related to mobile and wireless communications including frequencies, signals, antennas, and multiplexing techniques. The course discusses frequency ranges used for mobile communication and how signals are represented. It also examines antenna types including isotropic radiators, dipoles, directed, and sectorized antennas. The document outlines multiplexing methods such as FDM, TDM, CDM and modulation schemes including ASK, FSK, PSK and their advantages.
Radio broadcasting involves the one-way transmission of audio over radio waves to reach a wide audience. The document discusses the key components of radio broadcasting including categories of broadcasters (MW, FM, SW), studios, transmitters, antennas and the need for acoustic treatment of studios. It provides details on All India Radio's network in India and compares AM and FM broadcasting methods.
AM – Frequency spectrum – vector representation – power relations – generation of AM – DSB, DSB/SC, SSB, VSB AM Transmitter & Receiver; FM and PM – frequency spectrum – power relations : NBFM & WBFM, Generation of FM and DM, Armstrong method & Reactance modulations : FM & PM frequency.
The document provides details about a training internship at Doordarshan Kendra Lucknow. It describes the three main divisions of Doordarshan Kendra Lucknow - the studio, transmitter, and earth station. The studio is where various television programs and serials are recorded. The transmission section modulates and transmits both audio and video signals. The earth station communicates with satellites to downlink and uplink signals over long distances.
This document provides a summary of Abhishek Prasad's 12-day training report at Doordarshan Kendra Patna from December 4th to December 24th, 2012. The report discusses Doordarshan's history and operations, as well as technical aspects of television like standards, scanning, cameras, color signals, studios, transmitters, and more. The training focused on understanding the equipment and processes used in Doordarshan's television broadcasting activities.
This document provides an overview of Doordarshan Kendra's industrial training on television broadcast systems. It discusses Doordarshan as India's public service broadcaster, established in 1959. It then focuses on Jammu Kendra, describing its location, studios, transmitter section, and satellite usage. The document covers fundamentals of television like picture formation, resolution, color, and standards. It describes the key components of a television studio and transmission setup, including lighting, cameras, microphones, sync pulse generators, and vestigial sideband transmission. Modes of transmission like satellite communication and microwave are also summarized.
Industrial Training Report at DDK Mandi House New Delhirajeevkr35
The document provides information about Rajeev Kumar's internship at Doordarshan Kendra in New Delhi. It includes an acknowledgement section thanking those who helped and guided him. The preface discusses how the internship helped develop his professional skills and gain real industry experience. It also provided an opportunity to learn new technologies. The certificate section confirms Rajeev successfully completed his internship under the guidance of Mr. Gurjeet Singh and Amita Gautam at Doordarshan Kendra from June 20th to July 15th 2016.
The document provides details about Sushant Shankar's 4-week summer training program at Doordarshan Lucknow under the guidance of Mr. R. Naithani. It includes a declaration signed by Sushant that the work is original. It also includes a certificate signed by Mr. Naithani confirming that Sushant completed the training program. The document then acknowledges and thanks various people who helped and supported Sushant during the training.
This document provides information about Doordarshan Kendra in Raipur. It discusses Doordarshan's headquarters and staff in Raipur. It describes the various programs and services provided by Doordarshan such as awareness, education, and entertainment programs. It then provides details about the components of a television studio including cameras, lighting, audio equipment, and vision mixing. Additional sections describe the earth station, transmission center, antennas, outside broadcasting vans, and Doordarshan's setup in Raipur.
This document discusses various techniques used to improve mobile radio link performance including equalization, diversity, and channel coding. It describes equalization techniques that compensate for intersymbol interference caused by multipath. It explains different types of diversity including spatial, time, and frequency diversity that are used to mitigate fading. Specifically, it outlines four common spatial diversity techniques: selection diversity, maximal ratio combining, equal gain diversity, and scanning diversity. The document also discusses time diversity and RAKE receivers used in code division multiple access systems to exploit multipath for additional time diversity gain.
The document defines communication and its basic elements, which are a transmitter, channel, and receiver. It describes transmission media as the pathway that carries information between sender and receiver. The two main types are wired/guided media and wireless/unguided media. It also discusses analog and digital signals, periodic vs aperiodic signals, baseband vs broadband transmission, noise and signal-to-noise ratio, multiplexing, and provides short notes on communication through the ionosphere and DSB-SC and VSB modulation techniques.
ppt Or report of training on doordarshan TV broadcasting Siraj Ahmed
The document provides an overview of broadcasting at Doordarshan Kendra in Silchar, India. It discusses the key components of a Doordarshan studio including the studio itself, lighting, acoustic systems, cameras, and transmitter. It also describes the earth station that is used to send program signals to satellites for transmission and reception, and outlines the basic process of transmission from uplinking to satellites to downlinking to receivers.
Small-scale fading in wireless channels is caused by multipath propagation. There are three main effects: rapid signal strength changes over small distances/times, random Doppler shifts from multipath signals, and time dispersion of echoes. Multipath results from reflection, diffraction and scattering off surroundings. Several methods measure multipath structure including direct RF pulse systems, spread spectrum sliding correlators, and frequency domain channel sounding using vector network analyzers. These techniques help determine power delay profiles and understand time-varying multipath effects.
The document provides information about a communications systems course, including:
- The lecturer's contact information and grading breakdown
- An outline of the topics to be covered in each of the 16 weeks including transmission media, wireless communication, and mobile networks
- Expectations that students can interrupt with questions, should try to solve problems themselves before asking for help, and should review notes after class
- An index of subtopics to be discussed like historical background, communication system components, analog and digital systems, and important communication systems.
This document provides an overview of Doordarshan High Power Transmitter in Kanpur, including:
1. It discusses the history and components of Doordarshan, including TV studios, vision mixers, earth stations, and OB Vans.
2. While Doordarshan was an important part of electronic media in India, it is now losing viewers due to a lack of engaging content for youth and not adapting to changing market trends.
3. Suggestions are provided to help Doordarshan modernize and better utilize its resources, such as promoting content on social media and allowing more creative freedom.
This chapter discusses small-scale fading and multipath propagation effects in mobile radio channels. It explains that multipath waves traveling along paths of different lengths interfere at the receiver, causing rapid fluctuations in signal strength over short distances. The key points are:
1) Small-scale fading is caused by multipath interference and depends on factors like surrounding objects, signal bandwidth, and mobile speed.
2) Multipath propagation can be modeled using the time-varying impulse response of the channel.
3) Important parameters used to characterize fading include coherence bandwidth, Doppler spread, coherence time, delay spread, and Ricean/Rayleigh distributions.
The process of communication and Basic Block Diagram of Communication system is presented in this PPT.
The various Blocks like Information Source, Transmitter, Communication Channel, Noise, Receiver and Destination Blocks are discussed in detail
Doordarshan is India's public service broadcaster and one of the largest in India in terms of studio and transmitter infrastructure. It began broadcasting in 1959 and has grown to include 1500 transmitters and 70 production centers across the country. The document discusses the components and functions of a television studio, including cameras, lighting, microphones, vision mixers, audio consoles, and more. It also describes the earth station, which is crucial for broadcasting signals via satellite, and details the parameters of Raipur's earth station. Finally, it discusses television transmitters and the different types (VLPT, LPT, HPT), noting that Raipur's 10 kW HPT can cover an area of 90-110 km.
This document discusses telephone systems and multiplexing. It describes how telephone networks use circuit switching and have evolved from analog to digital systems. The basic telephone network consists of local loops connecting subscribers to switching offices, trunks connecting the offices, and switches establishing connections. Multiplexing allows transmitting multiple signals over one channel by combining them. Types of multiplexing include FDM, WDM, and TDM. FDM uses separate carrier frequencies. WDM uses different wavelengths of light. TDM transmits signals in sequential time slots. Multiplexing increases channel capacity.
This document provides an introduction to communication systems, including why modulation is needed, the basic components of transmitters and receivers, and different multiplexing techniques. It discusses how modulation converts information to radio frequencies for transmission, and how receivers convert the signals back down for processing. It also outlines several multiple access techniques used in cellular systems, including FDMA, TDMA, and CDMA, and provides block diagrams of cellular phone components.
ECE 618 covers topics related to mobile and wireless communications including frequencies, signals, antennas, and multiplexing techniques. The course discusses frequency ranges used for mobile communication and how signals are represented. It also examines antenna types including isotropic radiators, dipoles, directed, and sectorized antennas. The document outlines multiplexing methods such as FDM, TDM, CDM and modulation schemes including ASK, FSK, PSK and their advantages.
Radio broadcasting involves the one-way transmission of audio over radio waves to reach a wide audience. The document discusses the key components of radio broadcasting including categories of broadcasters (MW, FM, SW), studios, transmitters, antennas and the need for acoustic treatment of studios. It provides details on All India Radio's network in India and compares AM and FM broadcasting methods.
AM – Frequency spectrum – vector representation – power relations – generation of AM – DSB, DSB/SC, SSB, VSB AM Transmitter & Receiver; FM and PM – frequency spectrum – power relations : NBFM & WBFM, Generation of FM and DM, Armstrong method & Reactance modulations : FM & PM frequency.
The document provides details about a training internship at Doordarshan Kendra Lucknow. It describes the three main divisions of Doordarshan Kendra Lucknow - the studio, transmitter, and earth station. The studio is where various television programs and serials are recorded. The transmission section modulates and transmits both audio and video signals. The earth station communicates with satellites to downlink and uplink signals over long distances.
This document provides a summary of Abhishek Prasad's 12-day training report at Doordarshan Kendra Patna from December 4th to December 24th, 2012. The report discusses Doordarshan's history and operations, as well as technical aspects of television like standards, scanning, cameras, color signals, studios, transmitters, and more. The training focused on understanding the equipment and processes used in Doordarshan's television broadcasting activities.
This document provides an overview of television broadcasting and color television signals. It discusses:
1) How a television system works, including converting images/sounds to electrical signals for transmission and reconversion to images/sounds at the receiver.
2) The process of television broadcasting, including using AM for video and FM for audio transmission within a 7MHz channel.
3) Details of video modulation, including vestigial sideband transmission and chrominance modulation.
4) The development of color television standards including the NTSC system which transmits a luminance signal and chrominance signal containing color information via a 4.43MHz subcarrier.
The document provides information about the television standards and communication systems used at Doordarshan Kendra Patna from December 4th to December 24th, 2012. It discusses the PAL television standard used in India and describes PAL encoders and decoders. It also summarizes television principles such as scanning, cameras, color composite video signals, television studios, transmitters and more. The document was submitted in partial fulfillment of a Bachelor of Technology degree.
Doordarshan is India's national public broadcasting service. It had a modest start in 1959 and became the sole television channel in India until the mid-1970s. Doordarshan Indore uses uplink frequency 6174.5MHz and downlink frequency 3949.5MHz to communicate with the INSAT-3A satellite at 93.5° east. The document discusses Doordarshan's history and development, satellite frequencies, terrestrial television bands, and fundamentals of monochrome and color television systems including picture formation, scanning, number of lines, color mixing, and color difference signals which allow for compatibility with black and white TVs.
The document summarizes key concepts in television and video engineering, including:
1) Persistence of vision and frame merging allow the eye to perceive continuous motion from discrete frames displayed at a sufficient rate to prevent flicker. Higher frame rates are needed for closer viewing and brighter displays.
2) Interlacing creates two "flashes" per frame by scanning odd and even lines separately to increase the perceived frame rate without doubling the actual rate.
3) Color television transmits luminance (Y) and chrominance (I and Q signals) separately, with chrominance modulated on a subcarrier and bandwidth limited since the eye is less sensitive to chrominance changes.
4) PAL and
This document contains questions and answers related to television fundamentals. It covers topics like the functions of camera tubes, aspect ratio, luminance, illuminance, characteristics of the human eye, necessity of scanning in television systems, flicker, interlaced scanning, vertical and horizontal resolutions, composite video signals, pedestals, blanking pulses, and more. The document is divided into multiple units covering topics such as monochrome and color camera tubes, transmission and reception, color television systems, and more.
chapter-03.pptx TV transmission Balck and White ColorSANGRAMJADHAV49
1) Television fundamentals and transmitters are discussed, including aspects ratio, image continuity, pixels, resolution, scanning, and interlaced scanning.
2) Aspect ratio of a TV screen is 4:3. Image continuity is provided through persistence of vision which allows the eye to see a series of images without break.
3) Scanning involves using an electron beam to break an image into lines, both horizontally and vertically. Interlaced scanning scans every other line to increase frame rate without increasing bandwidth.
chapter-03cel.pptx deals with TV fundamentalsJatin Patil
1) Television fundamentals and transmitters are discussed, including aspects ratio, image continuity, pixels, resolution, scanning, and interlaced scanning.
2) Aspect ratio of a TV screen is 4:3. Image continuity is provided through persistence of vision which allows the eye to see a series of images without break.
3) Vertical and horizontal resolution are discussed in relation to number of lines and ability to resolve details. Interlaced scanning involves scanning odd and even lines separately to reduce flicker.
This document summarizes key concepts related to television imaging and the human visual system. It discusses how television aims to accurately present distant scenes in terms of geometry, brightness, contrast and color. It also explains fundamentals of human vision that television design is based on. Key aspects covered include the electromagnetic spectrum, color temperature, the definition of white, saturation, contrast, scanning and synchronization, color displays, and common video codecs.
Basics of Colour Television and Digital TVjanakiravi
Main characteristics of human eye with regard to perception of colours-mixing of colours. three standards of colour transmission system, CATV, DTH, HDTV & SMART TV
For TS-SBTET, C-18, DECE 6 Unit, By Nenavath Ravi Kumar, MIST Hyderabad
This ppt contains information about concepts of wireless communication, signal propagation effects, spread spectrum, cellular systems, multiple access systems.
SUMMER TRAINING REPORT ON DOORDARSHAN KENDRA SILCHERSiraj Ahmed
Doordarshan is India's national public broadcasting service. It broadcasts through satellite and terrestrial transmitters across India. Doordarshan began experimental broadcasts in 1959 and regular daily transmission in 1965. It remained India's only television channel until the 1990s. Color television broadcasting in India uses the PAL system, which transmits luminance (Y) and color difference signals (R-Y and B-Y) for compatibility with black and white receivers. The vision mixer in a broadcast production control room allows switching between different video sources like cameras, video tapes, graphics and effects.
1. The document discusses colour television systems and colour signal transmission.
2. It describes the NTSC, PAL and SECAM colour systems and how they modulate and transmit the colour difference signals.
3. Frequency interleaving is used to transmit the colour information by modulating the colour difference signals with a colour subcarrier frequency placed between harmonics of the line frequency.
John Watkinson Engineers Guide To Decoding EncodingSais Abdelkrim
1. This document is an excerpt from "The Engineer's Guide to Decoding & Encoding" by John Watkinson, which provides an introduction to composite video encoding and decoding.
2. It discusses the history and basic principles of the NTSC, PAL, and SECAM color encoding systems, which add a subcarrier-based chroma signal to the luminance signal in a way that allows color information to be transmitted without increasing bandwidth.
3. The excerpt focuses on how the phase and amplitude of the color subcarrier is modulated in NTSC and PAL to send two color components simultaneously, while SECAM frequency modulates the subcarrier and sends the components on alternate lines. This results in a complex signal spectrum
This presentation deals with topics such as Electromagnetic Spectrum, Wireless Propagation, Signals, Signal propagation effects, Spread spectrum and cellular systems.
The document is a project report on the television system. It discusses fundamentals of monochrome and color TV systems including picture formation, number of TV lines per frame, resolution, brightness, contrast, and color composite video signals. It also covers color television topics such as additive color mixing, color difference signals, bandwidth requirements, color carrier modulation, and chroma vectors. Finally, it discusses the PAL color encoding system, audio video chains in TV stations, and DTH broadcasting including downlink and uplink chains.
The document provides information about cathode ray tubes (CRTs). It discusses how CRTs work by using electron guns and a fluorescent screen to display images. CRTs were largely replaced by newer display technologies like LCD, plasma, and OLED due to lower costs and better features. The document then discusses the history of CRT development and provides details about color CRTs and their operation using three electron guns and phosphors to create color images.
DOORDARSHAN KENDRA SUMMER TRAINING REPORTAnkur Gupta
Doordarshan is India's public service broadcaster and one of the largest broadcast organizations in the country. It started terrestrial television broadcasts in Delhi in 1959 and color TV was introduced in 1982. The television standards used in India are PAL, with SDTV being 700 pixels per line over 625 lines per frame and HDTV being 1080 pixels per line over 1920 lines per frame. A television studio has three main areas - the action area for filming, the production control room for monitoring and mixing, and the central apparatus room housing technical equipment. Key components of a studio include cameras, lighting, microphones, and a vision mixer. TV signals are transmitted via antennas from high power transmitters mounted on tall masts and towers
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Imagine a world where software fuzzing, the process of mutating bytes in test seeds to uncover hidden and erroneous program behaviors, becomes faster and more effective. A lot depends on the initial seeds, which can significantly dictate the trajectory of a fuzzing campaign, particularly in terms of how long it takes to uncover interesting behaviour in your code. We introduce DIAR, a technique designed to speedup fuzzing campaigns by pinpointing and eliminating those uninteresting bytes in the seeds. Picture this: instead of wasting valuable resources on meaningless mutations in large, bloated seeds, DIAR removes the unnecessary bytes, streamlining the entire process.
In this work, we equipped AFL, a popular fuzzer, with DIAR and examined two critical Linux libraries -- Libxml's xmllint, a tool for parsing xml documents, and Binutil's readelf, an essential debugging and security analysis command-line tool used to display detailed information about ELF (Executable and Linkable Format). Our preliminary results show that AFL+DIAR does not only discover new paths more quickly but also achieves higher coverage overall. This work thus showcases how starting with lean and optimized seeds can lead to faster, more comprehensive fuzzing campaigns -- and DIAR helps you find such seeds.
- These are slides of the talk given at IEEE International Conference on Software Testing Verification and Validation Workshop, ICSTW 2022.
Building Production Ready Search Pipelines with Spark and MilvusZilliz
Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
Unlocking Productivity: Leveraging the Potential of Copilot in Microsoft 365, a presentation by Christoforos Vlachos, Senior Solutions Manager – Modern Workplace, Uni Systems
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
Infrastructure Challenges in Scaling RAG with Custom AI modelsZilliz
Building Retrieval-Augmented Generation (RAG) systems with open-source and custom AI models is a complex task. This talk explores the challenges in productionizing RAG systems, including retrieval performance, response synthesis, and evaluation. We’ll discuss how to leverage open-source models like text embeddings, language models, and custom fine-tuned models to enhance RAG performance. Additionally, we’ll cover how BentoML can help orchestrate and scale these AI components efficiently, ensuring seamless deployment and management of RAG systems in the cloud.
Communications Mining Series - Zero to Hero - Session 1DianaGray10
This session provides introduction to UiPath Communication Mining, importance and platform overview. You will acquire a good understand of the phases in Communication Mining as we go over the platform with you. Topics covered:
• Communication Mining Overview
• Why is it important?
• How can it help today’s business and the benefits
• Phases in Communication Mining
• Demo on Platform overview
• Q/A
Pushing the limits of ePRTC: 100ns holdover for 100 daysAdtran
At WSTS 2024, Alon Stern explored the topic of parametric holdover and explained how recent research findings can be implemented in real-world PNT networks to achieve 100 nanoseconds of accuracy for up to 100 days.
Pushing the limits of ePRTC: 100ns holdover for 100 days
Doordarshan Lucknow Summer Training Report
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Chapter-1
INTRODUCTION
Doordarshan is an autonomous Public Service Broadcaster
founded by the Government of India which is owned by
Broadcasting Ministry of India and is one of the two divisions of
Prasar Bharati. It is one of India's Largest broadcasting
organisation in terms of studio and transmitter infrastructure
established in 15 September 1959.It also broadcasts on digital
terrestrial transmitters. DD provides television, radio, online and
mobile services. Lucknow Doordarshan started functioning on
27th November 1975 with setup at 22,Ashok Marg, Lucknow.
Our training in Doordarshan Kendra Lucknow mainly focused
on these three divisions:-
1.1) STUDIO - Doordarshan is a leading broadcasting service
provider in India. DD Lucknow is full-flathead broadcast set up.
Many serials & program are being made here like "BIBI
NATIYON WALI", "NEEM KA PED" and "HATIM TAI" etc.
recorded in studio.
1.2) TRANSMITTER - Here the transmission of both audio and
video has been made. The transmission section does the function
of modulation of signal. Power amplification of the signal &
mixing of audio and video signal is done here.
1.3) EARTH STATION - The main function of earth station is
to make contact with satellite or communicate with it. The
signals from other transmitter are down linked here. Also the
signals here are uplinked to send it to larger distance.
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Chapter-2
EM SPECTRUM
The electromagnetic spectrum covers electromagnetic waves
with frequencies ranging from below one hertz to above
1025
hertz, corresponding to wavelengths from thousands
of kilometers down to a fraction of the size of an atomic
nucleus. This frequency range is divided into separate bands,
and the electromagnetic waves within each frequency band are
called by different names; beginning at the low frequency (long
wavelength)end of the spectrum these are: radio
waves, microwaves, THz waves, infrared, visible
light, ultraviolet, X-rays, and gamma rays at the high-frequency
(short wavelength) end.
Gamma rays, X-rays, and high ultraviolet are classified
as ionizing radiation as their photons have enough energy
to ionize atoms, causing chemical reactions. Exposure to these
rays can be a health hazard, causing radiation sickness, DNA
damage and cancer. Radiation of visible light wavelengths and
lower are called non-ionizing radiation as they cannot cause
these effects. In most of the frequency bands above, a technique
called spectroscopy. Electromagnetic waves are typically
described by any of the following three physical properties:
the frequency f, wavelength λ, or photon energy E. Frequencies
observed in astronomy range from 2.4×1023
Hz (1 GeV gamma
rays) down to the local plasma frequency of the ionized
interstellar medium (~1 kHz). Wavelength is inversely
proportional to the wave frequency, so gamma rays have very
short wavelengths that are fractions of the size of atoms,
whereas wavelengths on the opposite end of the spectrum can be
as long as the universe.
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Fig.1. Bands of EM Spectrum
Fig.2. Classification of Bands
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Chapter-3
FUNDAMENTALS OF TV SYSTEM
3.1 Picture Formation: - A picture can be considered to contain
a number of small elementary areas of light or shade which are
called PICTURE ELEMENTS. The elements thus contain the
visual image of the scene. In the case of a TV camera the scene
is focused on the photosensitive surface of pick up device and an
optical image is formed. The photoelectric properties of the
pickup device convert the optical image to a electric charge
image depending on the light and shade of the scene (picture
elements). Now it is necessary to pick up this information and
transmit it. The electron beam scans the image line by line and
field by field to provide signal variations in a successive order
then produces optical image. The scanning is both in horizontal
and vertical direction simultaneously. The horizontal scanning
frequency is 15,625 Hertz. The vertical scanning frequency is 50
Hz. The frame is divided in two fields. Odd lines which are
scanned first and then the even lines. The odd and even lines are
interlaced. Since the frame is divided into 2 fields the flicker
reduces. The field rate is 50 Hertz. The frame rate is 25 Hertz.
3.2 Number of TV lines per Frame: - If the number of TV
lines is high larger bandwidth of video and hence larger R.F.
channel width is required. If we go for larger RF channel width
the number of channels in the R.F. spectrum will be reduced.
However, with more no. of TV lines on the screen the clarity of
the picture i.e. resolution improves. With lesser number of TV
lines per frame the clarity (quality) is poor.
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3.3 Resolution:-The capability of the system to resolve
maximum number of picture elements along scanning lines
determines the horizontal resolution. It means how many
alternate black and white elements can be there in a line. The
vertical resolution depends on the number of scanning lines and
the resolution factor also known as Kell factor.
3.4 Grey Scale: - In black and white (monochrome) TV system
all the colors appear as gray on a 10- step gray scale chart. TV
white corresponds to a reflectance of 60% and TV black 3 %
giving rise to a Contrast Ratio of 20:1 (Film can handle more
than 30:1 and eyes capability is much more).
3.5 Brightness: - It reveals the average illumination of the
reproduced image on the TV screen. Brightness control in a TV
set adjusts the voltage between grid and cathode of the picture
tube (Bias voltage).
3.6 Contrast:- It is the relative difference between black and
white parts of the reproduced picture. In a TV set the contrast
control adjusts the level of video signal fed to the picture tube.
3.7 Viewing Distance: - Optimum viewing distance from TV
set is about 4 to 8 times the height of the TV screen. While
viewing TV screen one has to ensure that no direct light falls on
the TV screen.
3.8 Persistence of vision:- It refers to the optical
illusion whereby multiple discrete images blend into a single
image in the human mind and believed to be the explanation
for motion perception in cinema and animated films.
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Chapter-4
BROADCAST TV SYSTEM
Broadcast television systems are encoding or formatting
standards for the transmission and reception of terrestrial
television signals. It is categorized as Analog Television
Systems and Digital Television Systems.
4.1 Analog Television System:-
4.1.1 NTSC: -The first National Television System
Committee was developed in 1941 and had no
provision for color. In 1953 a second NTSC standard
was adopted, which allowed for color
television broadcasting which was compatible with
the existing stock of black-and-white receivers.
NTSC was the first widely adopted broadcast color
system and remained dominant until the 2000s, when
it started to be replaced with
different digital standards .
Fig.3. Analog television encoding system by nation; countries
using NTSC systems are shown in green.
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4.1.2 SECAM: - Development of SECAM began in 1956
by a team led by Henri de France working at Compagnie
Française de Télévision (later bought by Thomson,
now Technicolor). The first SECAM broadcast was made
in France in 1967, making it the second such standard to
go live in Europe. The system was also selected as the
standard for color in the Soviet Union, who began
broadcasts shortly after the French. The standard spread
from these two countries to many client states and former
colonies.
SECAM remained a major standard into the 2000s. It is in
the process of being phased out and replaced by DVB, the
new pan-European standard for digital television.
Just as with the other color standards adopted for broadcast
usage over the world, SECAM is a standard which permits
existing monochrome television receivers predating its
introduction to continue to be operated as monochrome
televisions. Because of this compatibility requirement,
color standards added a second signal to the basic
monochrome signal, which carries the color information.
The color information is called chrominance or C for short,
while the black-and-white information is called
the luminance or Y for short. Monochrome television
receivers only display the luminance, while color receivers
process both signals. In order to be able to separate the
color signal from the monochrome one in the receiver, a
fixed frequency sub carrier is used, this sub carrier being
modulated by the color signal. The color space is three-
dimensional by the nature of the human vision, so after
subtracting the luminance, which is carried by the base
signal, the color sub carrier still has to carry a two-
dimensional signal. Typically the red (R) and the blue (B)
information are carried because their signal difference with
luminance (R-Y and B-Y) is stronger than that of green
(G-Y).
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SECAM differs from the other color systems by the way
the R-Y and B-Y signals are carried. First, SECAM
uses frequency modulation to encode chrominance
information on the sub carrier. Second, instead of
transmitting the red and blue information together, it only
sends one of them at a time, and uses the information
about the other color from the preceding line. It uses
an analog delay line, a memory device, for storing one line
of color information. This justifies the "Sequential, With
Memory" name. Because SECAM transmits only one
color at a time, it is free of the color artifacts present
in NTSC and PAL resulting from the combined
transmission of both signals.
4.1.3 PAL :- Phase Alternating Line (PAL) is a color
encoding system for analogue television used in broadcast
television systems in most countries broadcasting at 625-
line / 50 field (25 frame) per second (576i).
All the countries using PAL are currently in process of
conversion or have already converted standards
to DVB, ISDB or DTMB.
The term PAL was often used informally and somewhat
imprecisely to refer to the 625-line/50 Hz (576i) television
system in general, to differentiate from the 525-line/60 Hz
(480i) system generally used with NTSC.
Accordingly, DVDs were labeled as PAL or NTSC
(referring to the line count and frame rate) even though
technically the discs carry neither PAL nor NTSC encoded
signal. CCIR 625/50 and EIA 525/60 are the proper names
for these (line count and field rate) standards; PAL and
NTSC on the other hand are methods of encoding color
information in the signal.
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4.2 Digital Television Standard:-
4.2.1 ATSC:- Advanced Television Systems
Committee (ATSC) standards are a set of standards
for digital television transmission over terrestrial, cable,
and satellite networks. It is largely a replacement for the
analog NTSC standard, and like that standard, used mostly
in the United States, Mexico and Canada.
The ATSC standards were developed in the early 1990s by
the Grand Alliance, a consortium of electronics and
telecommunications companies that assembled to develop
a specification for what is now known as HDTV.
ATSC includes two primary high definition video
formats, 1080i and 720p. It also includes standard-
definition formats, although initially only HDTV services
were launched in the digital format. ATSC can carry
multiple channels of information on a single stream, and it
is common for there to be a single high-definition signal
and several standard-definition signals carried on a single
(former) NTSC channel allocation.
4.2.2 DVB:- Digital Video Broadcasting (DVB) systems
distribute data using a variety of approaches, including:
Satellite: DVB-S, DVB-S2 and DVB-SH
DVB-SMATV for distribution via SMATV
Cable: DVB-C, DVB-C2
Terrestrial television: DVB-T, DVB-T2
Digital terrestrial television for handhelds: DVB-H, DVB-SH
Microwave: using DTT (DVB-MT), the MMDS (DVB-MC),
and/or MVDS standards (DVB-MS)
These standards define the physical layer and data link layer of
the distribution system. Devices interact with the physical layer
via a synchronous parallel interface (SPI), synchronous serial
interface (SSI), or asynchronous serial interface (ASI). All data
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is transmitted in MPEG transport streams with some additional
constraints (DVB-MPEG). These distribution systems differ
mainly in the modulation schemes used and error correcting
codes used.
4.2.3 ISDB:- The Integrated Services Digital Broadcasting is
a Japanese standard for digital television (DTV) and digital
radio used by the country's radio and television networks. ISDB
replaced NTSC-J analog television system and the previously
used MUSE Hi-vision analogue HDTV system in Japan, and will
be replacing NTSC, PAL-M and PAL-N in South America and
the Philippines. Digital Terrestrial Television Broadcasting
(DTTB) services using ISDB-T started in Japan in December
2003 and in Brazil in December 2007 as a trial. Since many
countries have adopted ISDB over other digital broadcasting
standards.
4.2.4 DTMB:- Digital Terrestrial Multimedia Broadcast is
the TV standard for mobile and fixed terminals used in
the People's Republic of China, Cuba, Hong Kong, and Macau.
Fig.4.DTT broadcasting systems. Countries using DTMB are shown in
purple.
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Chapter-5
VIDEO SIGNAL
What is Video Signal?
Video is nothing but a sequence of picture .The image we see is
maintained in our eye for a 1/16 sec so if we see image at the
rate more than 16 picture per sec our eyes cannot recognize the
difference and we see the continuous motion. In TV cameras
image is converted in electrical signal using photo sensitive
material. Whole image is divided into many micro particles
known as Pixels. These pixels small enough so that our eyes
cannot recognize pixel and we see continuous image ,thus at any
instant there are almost an infinite number of pixel that needs to
be converted in electrical signal simultaneously for transmitting
picture details. However this is not practicable because it is no
feasible to provide a separate path for each pixel in practice this
problem is solved by scanning method in which information is
converted in one by one pixel line by line and frame by frame .
Colour Composite Video Signal is formed with Video, sync
and blanking signals. The level is standardized to 1.0 V peak to
peak (0.7 volts of Video and 0.3 volts of sync pulse).
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Chapter-6
THE COLOUR TELEVISION
It is possible to obtain any desired colour by mixing three
primary colours i.e. Red, Blue and green in a suitable
proportion. The retina of human eye consists of very large
number of light- sensitive cells. These are of two types, rods and
cones. Rods are sensitive only to the intensity of the incident
light and cones are responsible for normal colour vision. The
small range of frequencies to which the human eye is responsive
is known as visible spectrum. This visible spectrum is from 780
mm (Red) to 380 mm(Violet). 3.7) ADDITIVE COLOUR
MIXING The figure shows the effect of projecting red, green,
blue beams of light so that they overlap on screen. Y= 0.3 Red +
0.59 Green + 0.11 Blue.
Fig.6. Additive Colour Mixing
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Chapter-7
SATELLITE COMMUNICATION
Satellite communication, in telecommunications, the use of
artificial satellites to provide communication links between
various points on Earth. Satellite communications play a vital
role in the global telecommunications system. Approximately
2,000 artificial satellites orbiting Earth relay analog and digital
signals carrying voice, video, and data to and from one or many
locations worldwide.
Satellite communication has two main components: the ground
segment, which consists of fixed or mobile transmission,
reception, and ancillary equipment, and the space segment,
which primarily is the satellite itself. A typical satellite link
involves the transmission or uplinking of a signal from an Earth
station to a satellite. The satellite then receives and amplifies the
signal and retransmits it back to Earth, where it is received and
reamplified by Earth stations and terminals. Satellite receivers
on the ground include direct-to-home (DTH) satellite
equipment, mobile reception equipment in aircraft, satellite
telephones, and handheld devices.
A satellite is basically a self-contained communications system
with the ability to receive signals from Earth and to retransmit
those signals back with the use of a transponder—
an integrated receiver and transmitter of radio signals. A satellite
has to withstand the shock of being accelerated during launch up
to the orbital velocity of 28,100 km (17,500 miles) an hour and a
hostile space environment where it can be subject
to radiation and extreme temperatures for its projected
operational life, which can last up to 20 years.
Satellites must be small and made of lightweight and durable
materials. They must operate at a very high reliability of more
than 99.9 percent in the vacuum of space with no prospect of
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maintenance or repair. The main components of a satellite
consist of the communications system, which includes
the antennas and transponders that receive and retransmit
signals, the power system, which includes the solar panels that
provide power, and the propulsion system, which includes
the rockets that propel the satellite.
Satellites operate in three different orbits: low Earth
orbit (LEO), medium Earth orbit (MEO), and geostationary or
geosynchronous orbit (GEO). LEO satellites are positioned at an
altitude between 160 km and 1,600 km (100 and 1,000 miles)
above Earth. MEO satellites operate from 10,000 to 20,000 km
(6,300 to 12,500 miles) from Earth. (Satellites do not operate
between LEO and MEO because of the inhospitable
environment for electronic components in that area, which is
caused by the Van Allen radiation belt.) GEO satellites are
positioned 35,786 km (22,236 miles) above Earth, where they
complete one orbit in 24 hours and thus remain fixed over one
spot. As mentioned above, it only takes three GEO satellites to
provide global coverage, while it takes 20 or more satellites to
cover the entire Earth from LEO and 10 or more in MEO.
Satellite communications use the very high-frequency range of
1–50 gigahertz (GHz; 1 gigahertz = 1,000,000,000 hertz) to
transmit and receive signals. The frequency ranges or bands are
identified by letters: (in order from low to high frequency) L-, S-
, C-, X-, Ku-, Ka-, and V-bands. Signals in the lower range (L-,
S-, and C-bands) of the satellite frequency spectrum are
transmitted with low power, and thus larger antennas are needed
to receive these signals. Signals in the higher end (X-, Ku-, Ka-,
and V-bands) of this spectrum have more power;
With the help of SATCOM Broadcasting services
include radio and television delivered directly to the consumer
and mobile broadcasting services. DTH, or satellite television,
services are received directly by households. Satellites also play
an important role in delivering programming to cell phones and
other mobile devices, such as personal digital assistants and
laptops. Satellite communications technology is often used
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during natural disasters and emergencies when land-based
communication services are down. Mobile satellite equipment
can be deployed to disaster areas to provide emergency
communication services.
The main advantage of satellites is that satellite technology is
ideal for “point-to-multipoint” communications such as
broadcasting.
Fig.7. Satellite Communication
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Chapter-8
EARTH STATION
A Ground station, Earth station or earth terminal is a terrestrial
radio station designed for extra planetary telecommunication
with spacecraft or reception of radio waves from astronomical
radio sources. Ground stations may be located either on the
surface of the Earth or in atmosphere. Earth stations
communicate with spacecraft by transmitting and receiving
radio waves in the super high frequency or extremely high
frequency bands (e.g., microwaves). When a ground station
successfully transmits radio waves to a spacecraft (or vice
versa), it establishes a telecommunications link. A principal
telecommunications device of the ground station is the parabolic
antenna.
Specialized satellite earth stations are used to telecommunicate
with satellites—chiefly communications satellites. Other ground
stations communicate with manned space stations or
unmanned space probes. A ground station that primarily
receives telemetry data, or that follows a satellite not
in geostationary orbit, is called a tracking station.
When a satellite is within a ground station's line of sight, the
station is said to have a view of the satellite. It is possible for a
satellite to communicate with more than one ground station at a
time. A pair of ground stations are said to have a satellite
in mutual view when the stations share simultaneous,
unobstructed, line-of-sight contact with the satellite.
In Earth Station Communication, a transponder can be used.
In air navigation or radio frequency identification, a flight
transponder is an automated transceiver in an aircraft that emits
a coded identifying signal in response to an interrogating
received signal. In a communications satellite, a satellite
transponder receives signals over a range of uplink frequencies,
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usually from a satellite ground station. The transponder
amplifies them, and re-transmits them on a different set of
downlink frequencies to receivers on Earth, often without
changing the content of the received signal or signals.
Fig.8.Earth Station
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Chapter-9
DIRECT-TO-HOME SATELLITE
BROADCASTING
Direct-to-Home satellite broadcasting (DTH) or Direct Satellite
Broadcasting (DBS) is the distribution of television signals from
high powered geo- stationary satellites to a small dish antenna
and satellite receivers in homes across the country. The cost of
DTH receiving equipment’s is now gradually declining and can
be afforded by common man. Since DTH services are fully
digital, it can offer value added services, video-on-demand,
Internet, e- mail and lot more in addition to entertainment. DTH
reception requires a small dish antenna (Dia60 cm), easily be
mounted on the roof top, feed along with Low Noise Block
Converter (LNBC), Set-up Box (Integrated Receiver Decoder,
IRD) with CAS (Conditional Access System). A bouquet of 40
to 50 video programs can simultaneously be received in DTH
mode.
Fig.9.DTH System
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DTH services were first proposed in India in 1996. The proposal
was not approved to due to concerns over national security and
negative cultural influence. In 1997, the Government of India
banned DTH services due to some security reasons but then on
some set parameters it is finally launched in India on 2 October
2003 by Dish TV.
Direct-to-Home (DTH) television is a method of receiving
satellite television by means of signals transmitted from direct-
broadcast satellites. The Government of India permitted the
reception and distribution of satellite television signals in
November 2000. The first DTH service in the country was
launched by Dish TV on 2 October 2003.
The Department of Space (DoS`) requires all DTH operators in
India to only use satellites commissioned by the Indian Space
Research Organisation (ISRO). DTH operators may use capacity
leased by ISRO from foreign satellites only if sufficient capacity
is not available on ISRO satellites.
The communication going from a satellite to ground is
called downlink, and when it is going from ground to a satellite
it is called uplink. When an uplink is being received by the
spacecraft at the same time a downlink is being received by
Earth, the communication is called two-way.
Generally frequency for uplink is kept higher than the
downlink. There is greater attenuation due to rain when the
signal frequency is high.
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Fig.10. Uplinking and Downlinking chain process
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CONCLUSION
Doordarshan is the oldest and the biggest Broadcasting media in
India. In my training session I learned a lot. Not only in
technical field but also in social field too. I got a great
experience of working in a Public Sector Company. I learned
about the recent trends in Broadcasting Media and also the
market strategies to maximize the profit using limited resources.
I would like to say that this training program was an excellent
opportunity for us to get to the ground level experiences. I
learned the way of work in an organization.
I have gained a lot of knowledge and experience required for
successful Communication Engineering.
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REFERENCES
1. http://www.ddlucknow.com
2. www.ddindia.gov.in/
3. https://en.wikipedia.org/wiki/Digital_terrestrial_television
4. https://en.wikipedia.org/w/index.php?title=Ground_station
&oldid=848823757
5. https://en.wikipedia.org/wiki/Satellite_television#Direct_b
roadcast_via_satellite