Different television systems

Jun 18 • Notes • 2014 Views • 7 Comments on Different television systems

Different television systems:-

HDTV:High-definition television (HDTV) is  digital television broadcasting system with greater resolution than traditional television systems (NTSC, SECAM, PAL). HDTV is digitally broadcast because digital television (DTV) requires less bandwidth if sufficient video compression is used.

HDTV

The most important aspect of the HDTV, and  1 which gives it its name is the increased the resolution. Standard definition NTSC broadcasts have 525 horizontal lines, and the PAL broadcasts are slightly better at the 625 lines. Both these systems the actual number of lines used to display  picture, known as active lines, is lesser than that. In addition, both PAL and NTSC systems are interlaced,i.e each frame is split into 2  fields, 1  field is the odd-numbered lines and the other is even lines. Each frame is displayed alternately and our brain puts them together to create  complete image of each frame. This have  an adverse affect on picture quality.

Closed-circuit television (CCTV): Closed-circuit television (CCTV) is the use of video cameras to transmit a signal to the specific place, on limited set of monitors. It differs from broadcast television that the signal is not openly transmitted, though it may employ point to point (P2P), point to multipoint, or  mesh wireless links.as  almost all video cameras fit the  definition,  term is most often applied to those used in areas that may need monitoring such as the casinos, banks,  airports, military installations, and convenience stores. Vidiotelephony is seldom called “CCTV” but those of video in Distance education , where it is the  important tool, is often so called In industrial plants, CCTV equipment may be used to observe parts of a process from a central control room, example when  environment is not suitable for the humans.

CCTV systems can  operate continuously or only as required to the  monitor the particular event. More advanced form of CCTV, utilizing  DVRs, provides recording for possibly many of the  years, with a variety of quality and performance options and extra features (such as motion-detection ). More recently, decentralized CCTV cameras based on IP, some equipped with the megapixel sensors, support recording directly to the Network attached the storage  devices, or the  internal flash for the completely stand-alone operation surveillance of the public using CCTV is particularly common in many of the  areas around world including  UK, where there are reportedly so many cameras per person than in any other country in  world. There and elsewhere, its increasing use has triggered debate about security versus privacy.

Public and private CCTV schemes can be deployed for a number of reasons:

Monitoring public areas to detect incidents and to coordinate police responses. CCTV is also used as an aid for enforcing exclusion orders (where an offender is barred from an area) – see box opposite.

Recording events for use as evidence and to inform investigations. For instance, on the boundaries of the Parliamentary estate, police on patrol alert CCTV operators of incidents via radio links. CCTV operators then record incidents as they unfold.

Directed surveillance of suspected offenders.

Deterrence of criminal activity – although the evidence for this is inconclusive Coaxial cable TV (CATV) systems:

For coaxial (or twisted pair) CCTV lines, use the CCTV/B or ESP CCTV/T. Protectors are available for coaxial RF lines.Transients can also be conducted into CATV systems via the mains power supplies. Many options for mains power protectors are available.

Installation

Connect in series with  coaxial cable either near where it enters or leaves each building or close to equipment being protected. This should be close to the system’s earth star point (to enable a good connection to earth).

HPCC (High-Performance Computing Cluster), also known as DAS (Data Analytics Supercomputer), is an open source Data intensive computing system platform. The HPCC platform incorporates a software architecture implemented on commodity computing clustures to provide high-performance, data-parallel processing for applications utilizing Big data. The HPCC platform includes system configurations to support both parallel batch data processing (Thor) and high-performance online query applications using indexed data files (Roxie). The HPCC platform also includes a data-centric declarative programming language for parallel data processing called ELC.

TV

Question Answers:

Q1: Give the Features & benefits of CATV?

Ans: Features & benefits of CATV:-

  •  Restricts through let voltage to below the damage levels of interface circuitry.
  • Provides repeated protection in lightning intense environments.
  • Low attenuation and high return loss over a wide range of frequencies ensures the protectors do not impair system performance.
  • Carries AC or DC power.
  • Substantial earth termination.
  • Supplied ready for flat mounting.
  • Strong metal housing.

Q2: What is PAL & SECAM ?

Ans: PAL & SECAM:

While the US, Canada, and Mexico adopted NTSC standards based on a 60 Hz frequency, most other countries developed color television systems based on 50 Hz. (The refresh frequencies varied as they were dependent on the operating frequency of the region’s electrical systems.) Most versions of PAL (Phase Alternating Line) and SECAM (Séquential Colour avec Mémoire) while still employing a 4:3 aspect ratio, had 625 horizontal scan lines. The 100 extra scan lines provided more picture detail, but some felt the slower, 25 Hz scan rate created a noticeable flicker.

Q3: What is MAC and how it works?

Ans: Multiplexed Analogue Components (MAC) was a satellite television  transmission standard, originally proposed for use on a Europe-wide terrestrial HDTV system, although it was never used terrestrially.

MAC transmits the  luminance and chrominance data separately in time rather than separately in frequency (as other analog television  formats do, such as composite vidios ).

Audio and Scrambling (selective access) of MCA:-

  • Audio, in format similar to NICAM was transmitted digitally rather than as an FM sub-carrier.
  •  MAC standard included a standard scrambling systemEuro crypt, a precursor to the standard DVB-CAS encryption system.

Q4: Write the elements to consider when designing any CCTV system?

Ans: Elements to consider when designing any CCTV system:-

  • scene, environment
  • camera
  • lens
  • transmission medium
  • monitor
  • Video Signal Management
  • Control Equipment.

Q5:  What are the approaches to create 3-D content ?

Ans: There are three main approaches to creating 3-D content:

  •  live camera capture
  • computer generated imagery
  •  2D to 3D conversion.

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7 Responses to Different television systems

  1. Aditya Kundan says:

    It’s a very informative article on different television systems and shows us the broader aspect of these systems. Through the advent of new technologies, the traditional pattern of implementing NTSC/ PAL system has taken a backseat and system like HDTV has gained advantage over these because of increased resolution, requiring less bandwidth. This has improved the quality of video that is broadcast making way for an all new experience of watching videos over television. Moreover, the article gives an insight to CCTV which we have seen installed in various important places meant for the security. But do we exactly know how it works? This article illustrates this aspect as well. With its use we can do recordings for a number of years with a variety of quality and performance and can be used for motion detection as well. This is a very useful piece of information shared. We come across several new terms SECAM, MAC,MCA whose working and meanings are well defined. Hence, this post makes us aware different systems used in television and their advantages.

  2. patlakshi says:

    this post comprises about the different television systems used in our life. Television has become now a days an integral part of life. Any information from one part to other can be transfer easily and that too in a short interval.

  3. suriya prakash says:

    This article helps to know about various types and uses of television systems rather than just entertainment purpose.

  4. Shashank Vivek says:

    Interesting Article ! Really good information about television system.

  5. Seetha Manoharan says:

    this article is helpful to know different television system. most of us dont know that.

  6. Dinesh says:

    one think i want to tell that as before gothroughing article i dont know this much of television system. and i thought CCTV is used only for monitoring system, But after reading this article i came to know about these television…

  7. SNEHA SINHA says:

    One of the best read articles on television systems that I came across…covering a detailed description about high definition television and closed-circuit television..

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