Home Surveillance Systems

Since the creation of the very first home surveillance system, technology has been evolving at such a rapid rate that the home security market can barely keep up. Much like the personal computer market, once a new technology gets released by one home security company, a rival company is nipping at their heels with their own advances. While this type of competition certainly keeps the burglar alarm industry on their toes, it also provides the general public with abroad selection of home security systems. Having such wide variety in the types of home invasion security systems available may seem redundant, because after all wouldn’t everyone want the “next big thing”? But the fact remains that while a portion of the population can afford to stay on top of the technological advances that lead the home surveillance industry, other homeowners are simply looking for an effective way to secure their homes against break-ins....
The variety in the availability of home surveillance systems is sometimes overwhelming but the choice in home security systems begins with the decision of whether to purchase an indoor or outdoor alarm. Indoor alarm systems are specifically built with sensors that are triggered by minimal stimuli, whereas outdoor alarm systems are built to be slightly less sensitive to prevent them from being triggered by the neighbor’s dog, a passing raccoon or a heavy rainstorm. Weather is another factor that plays in deciding which alarm system is for you, purchasing a system that is going to be placed within the house means that you can invest in extremely sensitive technology without having to be concerned about how it is going to weather.
Outdoor alarm systems; however, must be much more durable and able to withstand even the worst weather conditions without experiencing an interruption in service. Whereas indoor home security systems are generally found within the home, outdoor systems can be found mounted at entrances or exits of the home as well as on surrounding property such as perimeter fences. Due to the significant differences between the demands on each of these camera systems there is also a wide array of specialty cameras that feature within each niche.
When it comes to indoor alarm systems there are quite a few options available to the home surveillance customer, these options include: passive infrared detectors, ultrasonic detectors, microwave detectors, photo-electric beams, glass break detectors, and smoke, heat and carbon monoxide detectors. Each of these options offers a variety of coverage options throughout the home depending upon your needs as a homeowner.
Passive infrared detectors are one of the most frequently used options when it comes to home security and the reason for this is twofold: it offers reliable service while also being relatively affordable in comparison to many other alarm system options. The passive detectors are so named because they have no need to actively generate their own energy source unlike some other alarm systems. Passive infrared detectors work by monitoring an area for changes in temperature by first taking a reading on the overall temperature of the environment and watching for changes. As an infrared emitting object enters in to the area then it will cause a change in temperature which will be picked up by the system. The sensors within these passive devices are actually fairly complex and not only can they determine changes in temperature but they can compare areas within a monitored zone to identify whether or not an intruder is present.
Ultrasonic detectors differ from the passive infrared detectors in that they measure sound frequencies rather than temperature changes. These sound reliant systems emit sound waves in frequencies between 15 to 75 kHz that we are not able to hear and when there is an interruption of the sound waves due to an invading force the detector is able to identify intruders in the monitored area. Unlike the passive system discussed previously, the ultrasonic system must experience certain conditions in order for it to adequately function. The two conditions that are necessary for an ultrasonic system to function are that an object must be moving in order to disrupt the sound waves around it and the movement of the object must cause change in the ultrasonic frequency that surrounds it. Without these two conditions the ultrasonic detector is unable to detect change in the sound waves throughout the monitored area and as such it cannot function effectively.
Ultrasonic detection systems work much the same as echolocation works for bats; sound waves that are emitted from the system bounce back from objects within the room so that the system has a clear picture of what is in the room. Not all surfaces reflect sound waves; however, only solid surfaces are able to bounce back these sound signals and soft surfaces, like the body of an intruder, will soak up the energy without reflecting it back to the security system. Not many alarm companies utilize this type of technology in their systems anymore because it has become outdated in comparison to many of the much newer technological advances.
Microwave detectors are utilized in some home surveillance systems and on most occasions this type of technology is also combined with passive infrared detectors as mentioned above, to achieve full coverage of a home and lessen the likelihood of a system being falsely tripped. Microwave detectors work by sending out microwaves and monitoring for any reflected waves or a reduced intensity of waves that determines whether there is an intruder present. This type of system relies upon a microwave transmitter as well as a microwave receiver and when it is functioning correctly it can respond to a shift in frequency, motion that changes the amount of microwave beams that are sent back to the receiver or a shift in frequency caused by motion within the room. This type of technology is rarely used alone in any monitoring system because of the potential for false alarms.
Photo-electric beams are the types of systems often portrayed in spy movies, systems that transmit light beams (infrared or visible) in to the protected area. These beams are generally projected in multiple beams stacked on top of each other to prevent intruders from simply hopping over a single beam. These types of systems are generally not used in home surveillance systems because of the impracticality of them in this application. Most new surveillance systems that utilize photo-electric beams are also designed to detect utilization of light to manipulate and observe the beams. This advance means that all of those spy tips and tricks that you observe in the movies are only going to tip off the security system to your presence.
Glass break detectors are generally installed with many complete home surveillance systems to protect windows of the home. There are two options for glass break detectors, one which detects the sound frequency of breaking glass and one which detects the seismic activity associated with breaking glass. Where sound frequency detectors can be placed anywhere in the vicinity of a glass pane, the seismic detectors must be placed on the glass pane. Each of these systems work effectively in triggering an alarm once a glass pane in the home has been broken; however, most often the seismic detectors are implemented with complete home security systems.
Not all home security features are to monitor for intruders from outside the home, some features are to monitor for changes within the home atmosphere that make it dangerous to inhabitants. Smoke detectors are the most commonly recognized feature in this category; however, heat and carbon monoxide detectors are also popularly found in modern alarm systems. Unlike other parts of the home security system that much be activated to actively monitor the area, these types of detectors are set up to monitor the home 24-7 to ensure that at the first signal of danger, the home can be evacuated. While some of the current alarm systems have these features built in, other individuals choose to utilize independent detectors for these purposes. When using independent detectors in this situation it is important to regularly check the batteries to ensure that the systems are still working properly.
Outdoor surveillance systems have many uses in a variety of settings but they tend to be implemented more so in business and industrial settings. Variety is not limited to indoor security systems; however, when it comes out outdoor systems there are plenty to choose from including: vibration or inertia sensors, passive magnetic field detection, E-field, microwave barriers, micro-phonic systems, taut wire fence systems, fiber optic cable, and H-field.
These types of alarm systems work on the principle of the electrical circuit. A sensor is placed on a barrier or fence and has a continuous electrical circuit; however, upon vibration or movement the circuit is broken and the alarm is triggered to sound. While this type of system may sound as though it is rather unstable, it can be adjusted to respond to a variety of vibration levels and when done appropriately this system does not result in frequent false alarm incidences. This system type is also somewhat affordable; however, it must be mounted on a structure which deters many property owners from purchasing this variety of system.
The passive magnetic field detection system is a security system that must be buried or placed on top of a standing structure. This system functions as two wires run parallel to each other creating an electromagnetic field and whenever the field is broken or changed the signal processor of the system must analyze it. This type of system has a low false alarm rate but if often more costly to install; however, it is particularly efficient at detecting actual intruders. It should be noted though, that due to the magnetic field utilized by this type of system, it must not be installed for buildings located near radars or high voltage power lines.
An e-field surveillance system is so named because it uses an electromagnetic field on one of the two wires in the system, and the second wire that runs parallel to it senses changes and channels them to a signal processor that analyzes multiple aspects including the mass, movement and time that the intruder is present. All three of these aspects must be detected by the e-field system in order for the alarm to be sounded. While this type of system can be installed in a wide variety of situations, it is seldom used because it is expensive and has a high false alarm rate because the system is unable to determine between human intruders or stray animals. This type of system is also frequently triggered by extreme weather conditions making it something of a failure as far as outdoor alarm systems go.
Microwave barriers are a form of outdoor home surveillance system that work based on electromagnetic beams. The beam is emitted from a transmitter and is received by the receiver, this beam creates a wall that cannot be seen but can be broken through. When the electromagnetic beam is interrupted the security system will analyze the changes that have taken place and determine whether an intrusion is occurring. This type of alarm system is particularly affordable but not exactly the most practical system for use outdoors since it can be triggered by weather conditions as well as natural items that break the microwave barrier.
Microphonic systems are generally utilized by locations that wish to monitor a fenced in area. The system is installed with cables that attach to the fence and are sensitive to noise or vibration signals that occur when the fence is being cut or climbed. The benefit of this type of surveillance system is that it can be preset with a certain setting of conditions so that it can be configured to override naturally occurring triggers to the system. When these systems are not accurately set; however, they frequently register false alarms.
A taut wire fence system is an alarm system that is built in to a perimeter fence and they are generally used in some high security areas. These systems can detect any attempt to break through the fence barrier via detectors that are located along the perimeter of the fence. While other outdoor alarm systems may easily be tripped by wildlife in the area, the taut wire fence system can be adjusted to recognize only items that produce certain amounts of force on to the system, eliminating false alarms caused by small creatures. While this system is able to overcome some of the shortcomings of other surveillance systems, it is also susceptible to being bypassed by intruders digging underneath the fence. This is an older type of technology and although it works well for guarding higher security areas, it does not work well enough to be deemed useful in extremely high security areas because of the age of the technology employed.
Fiber optic cable surveillance systems work by measuring the amount of light that is sent through the cable, when an intruder attempts to pass through the perimeter the amount of light is diminished. When the receiver of the alarm system detects a difference in the amount of light that should be present and the amount of light that is present it triggers the alarm to sound. This type of system is generally installed on a fence or in cases of high security areas, in barbed tape. While this type of alarm is easy to implement it also has a particularly high rate of false alarms which does not make it a good candidate as the sole means of protecting high security areas.
The H-field system works by implementing an electro-magnetic field. Two cables are buried along the perimeter and the transmitter of the system releases radio frequency energy that is transmitted to the second cable. Much like other systems, this one is triggered when the amount of energy received by the receiver is less than under normal circumstances. Like most of the outdoor security systems, the H-field has a high false alarm rate and can also be affected by radio frequency noise rendering it useless.
There is certainly no lack in the availability of security systems and while some of the latter systems explained above may seem obtrusive for home security, there are always individuals looking to increase their privacy through the implementation of technology. For most households the average indoor surveillance system does the job well and not only provides protection to the family but also provides assistance when necessary by directly contacting the authorities. Most of the well known security systems offer a variety of packages that combine a variety of the indoor systems explained above for maximum coverage of the home, but depending upon your needs you may find that a minimal package offers the level of protection you are looking for on a budget that you can afford.