Posts Tagged ‘ Wireless Security System’



Wireless Night Vision Outdoor Security Camera

Written By:
Tuesday, June 1st, 2010

A wireless night vision outdoor security camera is a digital video camera with highly specialized features. Modern technological advancements have made these specialized features available at a very affordable price while offering high quality video images.

Outdoor security cameras differ from their counterparts the indoor security cameras, in that they are enclosed in a case that protects them from weather and environmental elements. Wireless night vision outdoor security cameras are often rated according to the protection that they offer. This protection is often described using an International Electrical Code standard called an Ingress Protection rating, International Protection Rating, or IP code. Most wireless night vision outdoor security cameras have an IP code of IP66 or IP67. IP66 means that the camera is dust tight and that water from powerful jets in any direction will have no harmful effects on the camera. IP67 means that the camera is dust tight and can withstand being submerged in water up to 1 meter in depth.

Digital video security cameras create images by using one of two special electronic sensor chips. Some digital security cameras use a Complimentary Metal Oxide Semiconductor or CMOS chip to create high quality color video images. Most wireless night vision outdoor security cameras use a Charged Coupled Device or CCD to create high quality color video using available visible light and high quality monochromatic or black and white video images using infrared (IR) radiation.

CCDs are highly sensitive to light energy known as photons. The CCD is able to transfer light energy into electrical energy in a somewhat similar process that a solar cell transfers sunlight into electricity. The electrical energy created by the CCD can be measured and digitally manipulated to create a video image. This is how a wireless night vision outdoor security camera creates high quality video in visible light conditions.

A wireless night vision outdoor security camera has a highly sensitive CCD that not only captures visible light but is inherently sensitive to radiation in the near infrared spectrum. This allows the camera to produce high quality video images in conditions of total darkness, with absolutely no visible light. These cameras contain an collection of IR Light Emitting Diodes or IR LEDs that surround the camera lens. The LEDs emit IR light that is not visible to the human eye, but lights up the cameras target area or field of vision like a flood light or spot light. Usually, the more LEDs that surround the camera lens, the farther the range that the camera can produce IR video in total darkness. Since IR radiation is not in the visible light spectrum, IR video is monochromatic or black and white.

Another specialized feature of a wireless night vision outdoor security camera is that it does not require a coaxial cable to transmit its video signals to the systems processor. “Wired” security cameras must be individually cabled to the processing unit. A wireless camera utilizes the 2.8 or 5.8 MHz radio band to transmit its video data by using an on-board antenna. The information is transmitted to a corresponding receiver that is normally located in the same area as the processor. After the receiver obtains the video signal it transfers it to the processor where a digital video file is created that may be viewed on a monitor or stored for later viewing or archival proposes.

Wireless night vision outdoor security cameras are available in different transmission ranges. The range is known as Line-Of-Sight or LOS. This means that the maximum transmission range stated for the camera is under conditions where there is an unimpeded line of sight between the camera’s antenna and the receiver’s antenna. Objects between them reduce the range, depending on the object’s size and material. Wireless cameras have LOS range capabilities of several hundred feet.

Additional features available for wireless night vision outdoor security cameras include the ability to record audio and the pan, tilt, and/or zoom (PTZ) functions. PTZ functions allow the camera to move in several directions and the zoom feature functions like a variable telephoto lens. These features can be controlled automatically or they may be controlled manually by remote control.

A wireless night vision outdoor security camera can be used anywhere that outdoor day/night video security and surveillance monitoring is needed. These cameras are often used for perimeter monitoring for both businesses and residents. In addition that can be used to provide monitoring for parking lots, driveways, and outdoor structures.

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DVR Wireless Security System

Written By:
Friday, May 14th, 2010

A Digital Video Recorder or DVR Wireless Security System is one of the most popular systems used for security and surveillance applications today. Although there are many variations of a typical DVR Wireless Security System, the general set-up for a security/surveillance application of this type involves the use of wireless Closed Circuit Television or CCTV cameras and a digital hard drive used to record the pictures or video sent to it by the CCTV cameras.

The key components of a DVR Wireless Security System include wireless CCTV cameras with antennas, a high speed digital hard drive, a wireless single or multi receiver, and a digital video recorder. Each of these components serves a specific function to provide a total package DVR wireless security system. Let’s take a closer look at each component.

The wireless camera comes in many varieties. There are dome cameras, box cameras, bullet cameras, PTZ or pan tilt and zoom cameras, and even explosion proof cameras. Wireless security cameras may capture still pictures and/or motion video and may provide the images in black and white or in color. Some cameras also come equipped with a microphone for capturing sound. In addition to these functions, wireless security cameras normally have an on-board transmitter that operates in the 2.4 GHz or 5.8 GHz bands. The broadcast range for these wireless cameras is usually somewhere between 200 and 700 feet depending upon environmental conditions.

The receiver is basically like a radio receiver or in-home wireless telephone receiver base. It receives the wireless signal transmitted from each camera and sends that signal to the DVR. Generally, receivers have more than one “channel”; that is, they can receive signals from more than one camera at a time. A receiver that can handle input from four different security cameras at one time is usually referred to as a four channel receiver.

After the camera’s signal is received, it is normally processed in some way before it reaches the DVR. The processing circuitry is normally found on an electronic “board” that is included with the DVR. This board may have one to several different file compression/decompression or CODECs wired into its circuitry. The purpose of using a CODEC is to minimize the size of the file to be stored on the DVR without sacrificing too much quality.

Digital video is basically nothing more than digital photographs taken at a rapid rate (normally up to 30 frames per second or fps). However, if you consider the digital size of a file for one photograph, you can only imagine the total size for thousands used to create a video. For example, a typical digital photograph may create a file 1.5 megabytes (MB) in size. One hour of video would be 30 photographs per second, times 60 seconds, times 60 minutes or 162,000 MB or 162 Gigabytes (GB) of information! A 250 GB hard drive would be filled in only two hours. However, CODEC boards reduce the file sizes drastically allowing for several hours to days of recording without filling up the hard drive.

Most DVR wireless security systems also include a monitor to view the cameras’ output in real time as well as to view the playback of recorded video. The monitor may be a small wireless unit itself or can be a larger LCD type monitor used with most computer systems.

There are many benefits to using a DVR wireless security system. Technological advances have made the components relatively inexpensive so that these systems can not only be used by businesses but can be used by consumers to provide security surveillance for the home. Wireless systems have the added benefit of placing the cameras in strategic places that are unlikely to be seen by potential criminals and vandals. In addition, DVR wireless security systems do not require signal transmission cables from the camera to the DVR, making installation much simpler and neater as well.

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