Outdoor Video Surveillance
Features of Outdoor Video Surveillance Systems
When organizing outdoor video surveillance, there are several factors to consider, such as:
- The distance between surveillance cameras and the receiving equipment (video recorders, servers, monitors).
- The electromagnetic environment at the monitored location (level of interference).
- The method of providing power to the cameras.
- The availability of artificial lighting during the night.
These factors directly influence the choice of equipment, signal transmission method, and the overall configuration of the video surveillance system.
Outdoor Video Surveillance Setup
The outdoor video surveillance camera is undoubtedly the core component, but you will also need connecting lines for transmitting the video signal and providing power.
Here, the distance from the cameras to the control point is a key consideration. For short distances, such as when equipping the surrounding area of a private home, coaxial cables are sufficient. For longer distances (around 1 km), twisted pair cables and the corresponding equipment should be used.
There are ready-made outdoor video surveillance kits available, but when choosing one, it's important to take into account some specific features.
Next, we turn to the power supply of the surveillance cameras. When the cameras are located far from the power supply unit (for 12V or 24V DC power), voltage drops can become significant, making the system’s performance questionable. Possible solutions include:
- Using cameras that operate directly on 220V AC.
- Placing a secondary power supply unit close to the cameras (this requires the power supply to be weatherproof or housed in a waterproof box).
In the second case, attention should be paid to the operating temperature range of the power supply unit, as it will still need to be connected to a 220V AC power source, which means running power cables.
Outdoor Surveillance Specifics
In the absence of outdoor lighting, infrared (IR) illumination might be the only solution. However, this is also a bit uncertain. Don’t be fooled by the claimed IR range in the technical specifications, such as 30 meters. Actual performance varies, and testing each model is the best way to determine the effective range.
Another important consideration is protection from electrical interference (e.g., lightning protection). For long cable runs, this shouldn’t be neglected.
Additionally, vandal resistance is crucial, especially in high-risk areas. Ideally, cameras should be placed in hard-to-reach locations. However, this can make maintenance difficult. To solve this problem, special housing can be used. It’s important not to be swayed by claims of vandal-proof cameras that are mounted on simple brackets. These are still vulnerable. The best solution is a metal dome (sphere) with a minimally sized hole for the lens, securely attached to a sturdy structure, preferably not using short self-tapping screws.
Hidden installation of video surveillance cameras is optimal if it aligns with the surveillance goals and objectives.
Outdoor Wi-Fi Video Surveillance
Using Wi-Fi technology for outdoor video surveillance can be practical when the distance between the camera and the router does not exceed 100 meters. This is a rough estimate and depends on local factors.
Naturally, an outdoor Wi-Fi camera needs to have appropriate weatherproofing. Other considerations related to choosing and using such cameras can be found [here].
The need for power connection limits the potential installation locations for the camera. It doesn’t make sense to run wires to the camera from the control point, as this negates the purpose of wireless video signal transmission.
Wi-Fi surveillance is particularly effective when the camera is placed on one side of the street and the equipment that processes the signal is placed on the other. This avoids the need to lay connecting lines across the street, which is a major advantage in urban areas. The power source can be located close to the camera installation point, for example, on a building wall or a streetlight pole.
However, as previously mentioned, high interference in the Wi-Fi installation location can make stable operation problematic. In conclusion, Wi-Fi video surveillance should only be considered when other options are not feasible.
Cables for Outdoor Video Surveillance
Outdoor video surveillance systems are exposed to the following conditions:
- Variable temperatures.
- High humidity.
- Mechanical stress and UV radiation.
All these factors must be considered when selecting cables and wires for outdoor installations. Additionally, the method of laying the cable infrastructure can impact the reliability of the video surveillance system. Common methods include:
- Running cables along walls and other supporting structures.
- Hanging cables on a supporting wire (aerial installation).
- Laying cables in underground pipes or trenches.
The first two methods are the most common, especially for smaller installations. The simplest and most convenient method is to run cables along existing supporting structures, which most installers prefer if possible.
When selecting cables for video surveillance, both video signal transmission and power supply must be considered. A combined cable (e.g., KVK) consisting of a coaxial wire and power supply wires can be used.
It’s important to pay attention to the wire gauge for power lines to minimize voltage loss. The best practices for powering surveillance cameras are covered in detail [here].