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CCTV / Video surveillance Ravi P. Agrahari (Science & Technology)
• The key components of every Closed Circuit Television (CCTV) system are: single or multiple cameras, recording device and a monitor. Closed Circuit Television (CCTV) systems are broadly divided into two known types, namely: wired CCTV systems and wireless CCTV systems. Wired CCTV systems bind all three key components of a CCTV system with cables while a wireless CCTV system comprises of a wireless camera that need not be connected to the recording device and monitor.• Both of these systems have distinct advantages and disadvantages associated as different types of technology are employed to provide security and reliable monitoring.
Wireless CCTV systems• Wireless CCTV systems are increasingly becoming a popular choice among CCTV buyers on account of the ease of installing such a system, lack of cabling requirements and assured mobility. The key advantages are:• A wireless camera can be moved to other locations requiring observation while it is difficult to move a wired camera.• Best suited for locations requiring temporary observation or in a temporary location.• Wireless camera can be hidden to detect theft or pilferage• Wireless recording and monitoring device need not be in the same line of sight allowing observation of any place from another remote location.• Wireless systems are cost effective, re-deployable and portable.
At the same time, there are some disadvantages of wireless CCTV systems, which are listed below :-• Wireless systems require a dedicated frequency to transmit signals from the camera to the receiving and recording station.• Frequencies may be subject to various interruptions by use of electric motored products, air conditioning, fluorescent lighting or cordless telephones which affect the picture quality.• Wireless camera may not provide the best picture quality as such systems are susceptible to picture distortion while wired cameras provide relatively better picture quality.• Wireless CCTV cameras may need electric power which implies a wire runs through the camera though the video connection is wireless.• Wireless systems require wireless technology-specific expertise to diagnose and fix break downs in the system.
Wired CCTV Systems Wired CCTV systems connect the camera to the recording device and monitor with the help of standard coaxial cables or Unshielded Twisted Pair (UTP) cables or fiber optic cables.The key advantages of wired CCTV systems are:• Provides the best picture quality with zero interference• The camera can be located hundreds of meters away from the recording or monitoring equipment.• All sensors can be run from a single power supplyThe key disadvantages are:• Cabling and installing can be a tedious task, requiring help from experts• Observation is fixed to a specific area and the camera cannot be easily moved to another location.Overall, wireless cameras are relatively more expensive than traditional wired cameras. Wireless CCTV systems are a preferred choice in specific locations devoid of easy cabling facilities and for individuals requiring an easy-to- install solution. The wired CCTV system is a preferred choice when good picture quality and economy considerations gain precedence.
CCD stands for Charged Coupled Device, which isthe name for the digital micro chip producing thepicture signal.The lenses of these CCD Cameras, focuses the lightonto that chip. The chip has thousands of microcells, which react to light sensitivity and colourfrequency.
The difference between digital CCTV and analogue CCTV is allaround the encoding of the signal. Here are the major differences: Digital CCTV Analogue CCTV Store as many recordings, from as many You need to change the tape every day, andcameras as you want. Youre only limited by the have the space to store the videos. size of the data storage on your computer or server.Image quality is superior and doesnt degrade When you copy or record over tapes the pictureover multiple copies or time, and its cheap to quality degrades, so youll need to replace them.copy data to CDs to pass information around. Digital CCTV recorders, or DCRs record up to Analogue systems and VCR record from each 100 images per second, and can record camera in turn. simultaneously from each cameraIts easy to sort through recorded data, and you You will need to manually search through can even connect to the digital CCTV system recordings to find the incident you want.over the internet to check on recordings or look through the archive.
Is digital CCTV best ?For the security industry this is the debate of thedecade. Whilst analogue CCTV products, which arehighly developed and work very well in mostapplications currently dominate the industry, thereare a number of leading companies successfullybringing true digital and IP-based CCTV solutions tothe market.
IP Security Camera System• IP Installations have two advantages to analogue CCTV Recording Systems:• If your business premises are large, the immense saving of cable costs will make the installation more affordable.• Your CCTV application needs to be of a very High Specification. This could be in Banks, Public Transport, Train Stations, Airports, Military compounds, Police and / or any other high security application. IP Mega Pixel Cameras can then be utilized and provide for up to 4x higher picture definition/ resolution than conventional CCD Cameras. Advanced Camera Intelligence features and the incorporation of these Cameras into manufacturing processes are another advantage.
• IP CCTV Specialists can use existing LAN (Local Area Network), expand it where necessary, or install a completely new one. We also offer several types of specialized wireless network solutions.
Hybrid CCTV SystemsA Hybrid CCTV System can record and display IPCameras and Analogue Cameras into the sameSecurity Recorder.This makes it possible to take full advantage ofadvanced features like video analytics, eventcontrolled functionality, Megapixel Resolution andexpansion via the existing LAN Network, whilst alsoconnecting standard analogue (aging technology)CCTV Cameras.
When is a Hybrid CCTV System feasible?• Do you currently have an existing analogue (all cameras which are still wired back to DVR or VCR via Coaxial Cable) CCTV System installed at your premises?• Do you need to upgrade or expand your current system?• Would you like to invest into something future proof - and not into an aging- soon out of date technology - avoiding repetitive investments in the near future?• Would you like to invest into a state of the art system, but not abandon the current system completely, not rendering it a mis-investment?
Then a Hybrid CCTV Solution is right for you. When we install one at your premises you will have the following benefits:• We can incorporate all your existing cameras into our modern state of the art system.• We can add advanced features and functionality to them, which are traditionally only ascribed to IP Cameras.• All new cameras installed will be IP Megapixel CCTV Cameras, providing an up to 30 times higher image resolution than analogue cameras.• Have the option of replacing Analogue Cameras with IP Cameras bit by bit as the need arises.• Take advantage of remote monitoring of all your cameras through the internet or company LAN.• Get Alarm e-mails, text messages and images triggered by defined alarm events.
Video recording system in CCTV There are three kinds of Video Recording Systems:1. VHS Video Recorder2. DVR Hard Disk Recorder3. NVR Network Video Recorder.
Definition DVR and NVR (Digital Video Recorder & Network Video Recorder)• VHS Video Recorder: A CCTV System , using a normal video recorder would be classed ANALOGUE = not Digital. The low recording quality has been overtaken by digital video recorders. VHS Video Recorders are what you want to replace... if you have any.• DVR Hard Disk Video Recorder: A CCTV System, utilizing a DVR to record video data would be classed DIGITAL. Even though the CCD Camera transports an analogue 1v video signal right up to the recorder input. The DVR converts the signal into a MPEG4 or other internet/storage friendly stream. Several months of recordings can be held on a DVR, without the need of ever changing any tapes. Many modern DVR also provide the facility to be assigned an IP Address and therefore allow operators to view live as well as recorded video via LAN and or the Internet. Yet, this does not make the system a IP Camera System. Many customers ask us to install an IP Camera System because they would like to be able to watch their premises remotely. In most cases we then recommend to install a DVR system - NOT IP.
• NVR Network Video Recorder: A CCTV System using NVRs to record video would also be classed as Digital. Rather than getting accessing only the recording system via the LAN or Internet as with the DVR, with an IP Camera system every single Camera needs network communication with the recording device. The main reason for going with IP, is the reduction of cabling and labour cost at large premises, which DO ALREADY HAVE a fully installed Local Area Network. The CCD Chip signal in the IP Camera is converted into a network streamable signal straight away and needs to be transported to the NVR just like e-mails or a video clip from youtube. Currently the most cost effective and best quality / reliable solution is DVR Hard Disk Recording. Only large and multi building premises with existing LAN Networks make IP Camera Systems cost effective.• One Technology that will change the balance in the future is the Mega Pixel Camera Technology. Mega Pixel Cameras provide a very high picture resolution as well as intelligence functions. This will become interesting when the price comes down a few hundred percent. We offer installation of mega pixel cameras mainly for high profile applications. Also, Ideal CCTV can combine existing DVR Systems with IP Camera Systems. So if you install a DVR Recording System now, it can be incorporated and upgraded in the future. Hopefully I have been of some assistance in bringing some light into this terminology for you.