General Requirements for Surveillance Systems
The requirements for a surveillance system depend on the specific tasks it is designed to accomplish. While general safety and installation standards apply universally, selecting the right components and ensuring optimal performance require careful consideration of individual system goals.
Indoor vs. Outdoor Surveillance
Outdoor Surveillance
Outdoor cameras must be built to withstand environmental challenges. Their protection level is indicated by the IP (Ingress Protection) rating, which specifies resistance to dust and water:
- Dust Protection: A first digit of 5 means dust-resistant, while 6 signifies dust-tight.
- Water Protection: A second digit of 3 ensures rain protection, while 5 and 6 indicate resistance to water jets.
For outdoor setups, a minimum rating of IP63 (dust-tight and rain-resistant) is recommended.
Indoor Surveillance
Indoor systems can forgo weatherproofing but should focus on resolution, field of view, and lighting conditions to meet specific monitoring objectives.
Requirements for Cameras, Monitors, and Recorders
Cameras
The choice of camera depends on:
- Field of View (FoV): Determined by the focal length; wide-angle lenses cover large areas, while telephoto lenses focus on specific details.
- Resolution: The higher the resolution, the better the detail. Cameras with 1–2 MP (720p–1080p) are sufficient for most applications.
- Special Features:
- Backlight Compensation (BLC): Essential for entrances with backlighting.
- Automatic Iris Control: For fluctuating light levels in outdoor settings.
Monitors
- Resolution: Match the monitor’s resolution to the system's cameras and recorder to avoid bottlenecks in image quality.
- Effective Viewing: Operators can monitor 4–6 feeds effectively; dividing a monitor beyond this limit reduces situational awareness.
Video Recorders (DVR/NVR)
- Capabilities: Choose a recorder with features such as triplex (simultaneous recording, playback, and live viewing) or penta-plex (adds remote access and backup creation).
- Resolution Matching: The recorder must handle the resolution of the cameras without downgrading quality.
Application-Specific Requirements
General Monitoring
- Cameras should provide wide coverage with lower pixel density (20 px/m for detection).
- Monitors and recorders should support real-time monitoring of multiple feeds.
Object Identification
- Requires higher resolution: 250 px/m for clear identification.
- Monitors must display sufficient detail, especially for high-traffic areas.
License Plate Recognition
- Ensure cameras capture 15–20 px height for characters under ideal conditions.
- Environmental factors like glare and motion may require additional correction features.
Conclusion
- Surveillance system requirements vary by use case, focusing on tasks like monitoring, identification, and recording.
- Proper equipment selection—cameras, monitors, and recorders—is critical for effectiveness.
- Outdoor systems must meet environmental standards (e.g., IP rating), while indoor systems should optimize for resolution and coverage.
- Adhering to these guidelines ensures high-quality surveillance and operational reliability.