A successful video surveillance deployment involves more than just software. In this article we will discuss the importance of carefully selecting and installing your cameras as well as mitigating problems caused by the outdoor environment.
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When we think of camera placement, we normally think in terms of the optimal “field of view”. With any intelligent video surveillance (IVS) product this is even more important. AIRA has been designed to integrate with an existing camera infrastructure, so most times camera placement is a non-issue. However, for optimal performance, cameras must be between 1-2 storey’s from the ground. Camera angle is also important, and when you setup AIRA you will enter information on the camera angle. AIRA is not designed to work where the camera is pointed completely horizontally or vertically. Typical camera views are shown below:
Although AIRA is a highly sophisticated NVR capable of filtering the environment, certain situations will cause false alarms. However in cases of extreme weather false alarms will occur. With proper planning the negative effects of the environment can be mitigated. Ensure that the camera is as stable as possible after installation. Cameras which move sporadically due to wind will cause some false alarms. The problem is particularly magnified when using Pan-Tilt-Zoom cameras. AIRA is unaffected by rain and snow accumulating on the ground, however where rain and snow hits the camera lens directly, problems will occur. Try to shield the cameras from the weather where possible.
Like humans, AIRA requires an image with enough contrast sensitivity which enables it to detect certain events automatically. Contrast sensitivity is the ability to see differences in contrast between objects or parts of objects. At night, flood lights are recommended where thermal or infrared cameras are not employed to give AIRA the necessary contract difference between objects. If the image is in complete darkness AIRA cannot track and classify the objects. In low light scenarios, most cameras will produce an image which seems out of focus. Increasing the amount of light at night will increase picture quality dramatically. With regards to light placement, however, a flood light immediately close to the camera is not recommended. The strong light will highlight snow and will cause false alarms. Further, flood lights attract many insects at night, which in turn attract spiders who feast on the insects. The result can be infestation of insects on or around the camera which causes false alarms as they crawl across the camera lens. Moreover, having the flood light directly in the field of view of the camera creates poor visibility and false alarms as snow is artificially illuminated in the scene.
Poor video quality can be a result of a cabling or power issue. Here is a quick checklist:
- If running coax cable, make sure there is no interference caused by power cables in the vicinity
- Ensure that the cameras have the sufficient amount of power required for normal operation. Be aware that power requirements vary as outdoor housings require power for heaters and blowers which turn on intermittently.
- Ensure that all camera splices are done correctly and are weatherproof
- The most commonly recommended "coax" type is RG59/U, but this designation actually represents a family of cables with widely varying electrical characteristics. Other varieties include RG6/U and RG11/U. Respect the maximum distances per coax type: RG11/U for distances over 175 feet, RG6/U for distances to 175 feet, RG59/U minimum capacity requirements.
- Running network cameras over Ethernet cable will not result in quality degradation, as seen with analogue cameras over wide distances.
- If you are running Ethernet cabling for network cameras, keep the following distance and bandwidth limitations in mind when deciding on how many cameras to put on a single Ethernet cable. Network cameras may use the following standard network cabling:
- Gigabit Ethernet (over copper), 1000baseT: Speed: 1000 Mbps/Max Len: 100 meters/Cable: UTP, RJ-45 connectors
- Fast Ethernet, 100baseT: Speed: 100 Mbps/Max Len: 100 Meters/Cable: UTP, RJ-45 connectors
- Twisted Pair Ethernet, 10baseT: Speed: 10 Mbps/Max Len: 100 Meters/Cable: UTP, RJ-45 connectors
In order for AIRA to automatically send notifications when security policies are broken, a reliable Internet connection is required. A static IP is not required for outside users to connect to AIRA due to the inbuilt dynamic IP support. AIRA sends “health” packets each 15 minutes to Aimetis.com informing Aimetis of the server health. Each health packet is a meager 200 bytes. Bandwidth consumption between a connected AIRA Explorer and AIRA Server is approximately 220Kb/s. An Internet connection of 3 Meg download speed and 800 Kbps upstream speed is recommended for proper remote monitoring.