Digital surveillance is an effective, quick and easy method of video surveillance that has become increasingly popular with corporations and various other types of large businesses. There are two main reasons for this: digital data is quicker and easier to use and it makes remote surveillance possible from any location in the world.
Digital surveillance enables the transmission of live streaming or recorded video footage via the Internet or cellular networks to another PC or handheld device, providing immediate access to surveillance footage regardless of location. This can be very useful for monitoring activity in isolated areas, such as on oil rigs, but it can also be useful in large companies who have a number of branches throughout the country or the world.
Digital surveillance systems require cameras, a PC and a networking device to function. A network video device acts as a recorder, compresses the video stream, and stores it on the PC's hard drive. The most commonly used device is the digital video recorder or DVR. While it is possible to stream the footage live through a PC without a DVR, a DVR is needed for recording and storing the footage.
Working with digital video surveillance camera systems
How much footage can be stored depends on a number of things including resolution, number of frames per second, type of recording method (i.e. motion sensor or continuous recording), type of compression and the number of cameras used. Once the hard drive is full the system will automatically begin overwriting the oldest previously recorded footage. Hard drives are relatively inexpensive so it is advisable to buy as large a hard drive as possible; particularly if storage is a main concern.
Digital video recorders connect directly to the computer or they can come as stand-alone units with their own operating system. Stand-alone DVRs are generally more reliable and produce better quality images than those that connect directly to the PC. Most digital systems run through a wired network and the speed and quality of the images depends on the capacity (bandwidth) of the network and how much of it is available for use by the digital surveillance system.
Complete digital surveillance systems come with a quad processor (enabling the user to view up to four cameras on one screen), motion sensors, pan and zoom controls, CCTV camera connections, a monitor, servers (for remote monitoring), time-lapse recorder (such as a DVR) and software package. These can cost from as little as $400 to $2000 for an average, four-camera system. Larger systems with up to 16 cameras are available but can cost thousands of dollars.