This could include legacy detection technologies that incur high false alarm rates and/or no visual assessment. Sometimes the customer wants to replace the system completely; other times the goal is to provide an additional layer of video security to enable more accurate alarming. The ultimate goal is to end up with a solution that is simple yet reliable. This means that the system is not missing real events, but it also cannot generate so many false alarms that it creates “The boy that cried wolf” syndrome. There are many cases where systems have been all-out turned off because of this.
5. Will the customer be actively controlling the cameras?
This question relates to whether it is better to use fixed imagers that provide a constant vigil on areas of importance, or if pan/tilt systems can provide added value. Many installations incorporate a combination of fixed and pan/tilt systems so they can have the unblinking eye on certain areas, while using pan/tilt cameras to assess alarms or scan larger areas.
6. What is the current available infrastructure?
This question is important in any security project, however outdoor surveillance poses additional challenges because quite often the imagers are placed in remote areas that lack good sources of power or communication. The costs of installation are often greater because of these added challenges. These factors can greatly affect the design’s end result.
Answering these questions will get you started on the right foot when designing your installation, but you also need to consider the strengths and weaknesses of different imaging technologies.
IR illuminated cameras can provide identification levels of information, but only when used conservatively. It is common to expect too much in terms of capability. The chances of gaining an identifiable image outdoors at any distance is very slim, especially at night. Using IR illumination for identification is typically only recommended for use in areas where the ingress/egress is well defined, such as gates or doorways. These are locations in which cameras and illuminators can be strategically placed to optimize illumination.
Great care should also be taken to avoid uneven illumination and overtaxing the camera’s distance capabilities, as illumination levels degrade quickly with distance. An IR illuminator is just like a flashlight. Objects outside the cone of illumination are often less noticeable than if there was no illumination at all and there are many ways in which the effective distance can be cut down. Overall, the customer’s expectations should be set correctly regarding the chances of achieving identification.
For the most reliable detection and classification, the use of thermal imagers with good video analytics is a potent combination. If the infrastructure allows, the most straight forward and effective approach is to place imagers toe to toe along the perimeter of concern. This allows a virtual thermal fence in which objects crossing into the area will be detected, and in some analytics, classified for even lower false alarm rates. When infrastructure is limited, the imager placements may be limited to the buildings or other structures on the site. This will increase the number of imagers necessary to cover an area or perimeter as they are now looking out toward the perimeter.
Combining a thorough understanding of the imaging technologies you’ll be deploying with the answers to these six foundational questions should provide you with the information and confidence you need to design the best installation for your clients.