Understanding Video Surveillance Technology
Video Surveillance Technology or CCTV (Closed Circuit Television) can be grouped into three categories. All three technologies now record video digitally on a hardrive. The size of the hardrive is best determined based on the amount of cameras, the frame rate at which each cameras archives video and the resolution of each camera.
Camera resolution is a good way to classify the types of technology platforms available today. Analog cameras which record at 700 TVL (Television Lines) offer excellent viewing quality for distances from twenty to thirty feet, however, for more powerful requirements, the latest addition to the video surveillance market is HD CCTV. HD CCTV records at 1080P or two (2) megapixels which in resolution terms is measured by horizontal over vertical lines, in this case equal to 1920/1080. The advantage of HD CCTV is for existing coaxial cable systems which require an upgrade to improved viewing without the need to run new cable infrastucture. A new HD DVR and HD Cameras can be added with relative ease. The cost for an HD CCTV System versus a traditional analog CCTV system runs approximately 20% – 30% additional cost for the equipment while the installation expense should be about the same.
Megapixel technology is widely used with an IP Video Surveillance System. Megapixel Cameras range from one to twenty megapixels. Megapixel Cameras yield a significant improvement in resolution capabilities. There are now gigapixel cameras which are emerging on the video surveillance camera market. An IP Video Surveillance System has several advantages and differences as compared to CCTV. I will attempt to cover several of these advantages.
An IP Video Surveillance System is installed with Category 5 or Category 6 ethernet cable, terminated with an RJ45 connector which is then plugged into a network switch or a POE (Power over Ethernet) Switch. The POE switch powers the camera and eliminates the need for an outside or additional power source. IP Video Systems are also popular when an organization has a sophisticated network infrastructure in place with readily available network access points where cameras can be easily mounted and connected to the network. The use of Cat5 or Cat6 cable extends the lenght of a cable run and therefore allow for cameras to be used at a longer distance from the NVR and/or a network switch. Wireless transmission of the digital video signal has also become much more reliable and can be utilized within the framework of an IP Video Surveillance System allowing for a hybrid of wireless and wired IP Video Cameras. Most all IP Video Cameras come standard with two way audio capabilities.
Video Management Software (VMS) packages are available from a variety of software manufacturers such as Milestone, Exacq Vision, Ocularis and Video Insight. Most of the major IP camera manufacturers now include a basic VMS package if you purchase cameras and a Network Video Recorder (NVR) from them. The NVR is a key component of the IP Video Surveillance System in that it contains the VMS platform running the cameras. The programming and settings of the VMS platform determine the resolution, frame rate, storage capacity and access rights of your video. Multiple servers can be utilized in the case of a decentralized network system, conversely, cameras can send their video directly to a centralized, mainframe type server if requirements call for such an arrangement.
A good illustration of centralized versus decentralized system is a large banking instution such as Bank of America versus a smaller company with several locations. BofA has multiple cameras located at every branch. Those cameras probably save their video locally at the branch level, although all the video at any branch is available for viewing from any location on the company network. As an example, security personnel could pull up real time video from any branch to audit activites. After a security event, such as a robbery, video can be called up from the archive and moved over to a different location within the company network. Each branch may hold up to a month of video for their respective cameras, however, corporate could pull that data on a regular basis to maintain an ongoing archive for a longer periodif they determined that was necessary. So in this example, a decentralized IP Video Surveillance System is the best fit and allows management and security personnel to view, audit and archive large amounts of video footage from a single work station. In the centralized IP Video Surveillance System. A centralized server (NVR) can be tasked with managing several locations. One of the key issues to consider in both a centralized and decentralized design is the bandwidth that is available and the potential latency, or drag on the video feed and verall speed of the company network.
One of the other major features of an IP Video Surveillance System is the use of what is called Video Analytics. IP Video Surveillance Systems utilize database functions and sophisticated programming to enable the user to quickly comb through large amounts of data with relative ease. For example, let’s suppose a piece of expensive equipment was stolen from its location over the weekend. Using analytics, one could highlight the area where the equipment was last located and ask the VMS software to search video and find the point in time when the equipment was removed. Another example in a retail environment is counting customers entering a store and/or mapping traffic patterns. Doing this allows management to schedule personnel more efficiently, react to increases in customers and to design and analyze the overall layout and location of promotional kiosks or displays.
Video Surveillance has become more of a management tool in addition to the benefits it provides for security. Many customers use video to oversee their operation whether it be manufacturing, retail or hospitality to name a few. It enables managers to quickly audit live activities of their operation in addition to recalling events that occur such as customer interactions, work related accidents and operational miscues.
In closing, video surveillance systems have become much more useful in the efficient and safe operation of ones business. They provide indisputable proof by re-creating events and positively identifying people. The three levels of video surveillance technology are traditional CCTV, currently rated at 700 TVL resolution, HD CCTV which provides 1080P viewing quality on a coaxial infrastructure and IP Video Systems which use network cabling, allow for the highest camera resolution and have the most features such as built in two way audio, video analytics and management of video archive data. To determine which technology best fits your application and budget, one should consult with a security specialist who can conduct a site survey and make recommendations on the most appropriate video surveillance platform to meet your overall operational and security requirements.
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