Using Infrared to Improve Security Systems|
Since its development over 50 years ago night vision technology has grown to include a wide range of devices that in some manner or another create the ability to see in what for all practical intents is near or total darkness. Starting out as an active infrared system, early military night vision was little more than an infrared light source coupled with either special goggles that allowed a user to see in the infrared spectrum or an infrared sensitive electronic scope or screen that produced images using the light emitted by the infrared light source. These types of night vision systems are known as active infrared because they rely on an artificial source of infrared light to produce visible images. This sort of system lost favor with the military quickly however as it became easy for anyone with the proper equipment to view the infrared light source as well and adversaries were fast to take advantage.
The next step in night vision came with the development of passive night vision technology which basically takes any available light and electronically amplifies it to produce an image on a screen. This is known as light amplification night vision and it quickly became the dominant form of night vision as it is not so easily detected and preserves the covert abilities that make night vision so valuable. Passive night vision quickly went through several advancements and each represented what came to be known as generations of device technology. Each successive generation represents an improvement in the equipments ability to gather and amplify light and thus produce ever sharper and more detailed images. Currently, 4th generation night vision represents the highest order of this technology and remains controlled at the federal level, making it difficult for civilians to obtain such equipment. This has led to earlier generations such as 1st gen and 2nd gen becoming prevalent in the civilian sector. Although not as powerful or effective as 4th generation night vision technology, these earlier generations are still quite effective for use in the less demanding civilian sector.
Another more recent development has led to an even better option for those in the civilian sector who wish to procure their own night vision technology. Charge-coupled devices or “CCDs” have become the dominant type of technology used in digital cameras today. These devices basically take information in the form of light and convert it into electronic data which is manipulated within the electronics of the device to form an image which can be displayed or stored digitally. A side effect of the CCD is that in most applications they are sensitive to a wider range of the light spectrum than the human eye, meaning that light in the infrared and near infrared end of the light spectrum which is normally invisible to the human eye is very much visible to a CCD device. This is interesting because it means that most cameras and image producing devices which utilize a CCD can in effect be used as a type of night vision device as well.
The implications are obvious. If a business currently has a system of cameras installed for security purposes, it is very possible they can gain further benefit by adding an infrared light source to the system. The effect would be to create a security system that not only is effective during daylight hours, but capable of producing detailed images at night as well without any source of visible light. Of course, not all CCD devices are capable of taking advantage of infrared light. Some of these devices are equipped with filters that prevent light in the infrared spectrum from being processed for various quality and feature reasons. Should a person desire to find out if their camera is capable of detecting infrared light, they can either contact the manufacturer, or in many cases simply point an infrared device such as a remote control at the camera to see if the infrared light it emits is picked up.
One of the beneficial aspects of infrared lighting as it pertains to night vision technology is that almost all types of night vision technology except thermal imaging can benefit from an external infrared light source. Since most night vision devices rely on some form of CCD to produce images, the addition of an infrared light source can greatly improve the range and resolution of the device by adding more detectable light energy for the device to “see”. This is why so much of the night vision capable security cameras on the market today are being packaged with integral infrared light emitters. Usually arrayed in a circle around the camera lens, these emitters are generally LEDs that emit their light only in the infrared spectrum. The net effect is that invisible infrared light is directed wherever the camera is pointed, allowing the camera to produce images regardless of the ambient light levels.
Although generally effective, these camera/infrared light systems are limited in their range and resolution. Most of this limitation stems from the limited amount of infrared light they produce. These limits can be greatly expanded however by the addition of another external infrared light source such as a Larson Electronics LEDLB-20-IR IR Emitter Light Bar. Just like with normal visible light, increasing the amount of infrared light effectively creates a greater amount of illumination that is visible to the camera. With more light available, the cameras effective range and resolution is improved, expanding its field of view and effectiveness. This type of setup has proven extremely effective and is used extensively both in military and civilian applications. One of the best benefits to be had from this sort of supplemental infrared lighting is that it requires little to no modification of existing monitoring systems. Users can potentially improve, or even create night vision capability within their existing monitoring systems without the need to replace any of their existing hardware.
Business and companies interested in such upgrades and modifications should check with the manufacturer of their systems before beginning any such additions to their systems. Although it is not guaranteed that their systems are able to take advantage of an additional infrared light source, the mere fact that their system probably relies on CCD technology makes it likely. The savings in costs and increased effectiveness of their systems makes such an inquiry not only worthwhile, but just plain good sense.