Closed-Circuit Television (CCTV)

Closed-Circuit Television (CCTV)

Introduction:

Closed-circuit television (CCTV) systems have been a crucial tool in surveillance and security for many years. Given their long history, there have been numerous developments and advancements in this field. Understanding these trends, the latest achievements, and technologies, along with the critical aspects of a surveillance system, can significantly aid managers and experts in selecting and implementing an effective CCTV system. This article briefly outlines some of the most important considerations.

Standard Steps for Implementing a Surveillance Project:

In this section, we briefly review the key activities that need to be carried out before, during, and after the implementation of a surveillance project:

1. Theoretical Review and Main Components: At the beginning of the project, comprehensive studies on CCTV systems, components, standards, and current technologies should be conducted to clearly define the scope and dimensions.

2. Information Gathering of Available Companies: Efforts should be made to collect information on available companies and products through the internet, magazines, advertisements, and other sources. Based on security needs and the theoretical review, an RFP (Request for Proposal) should be prepared and sent to reputable companies.

3. Receiving Product Information: Technical and economic information received from companies should be studied thoroughly, and any ambiguities should be resolved through continuous communication with these companies.

4. Practical Testing of CCTV in Real Locations: Final users should be involved in the testing process to evaluate the capability of different camera brands and features in real conditions, with security experts and end-users present.

5. Compatibility Check with Other Systems: If other systems like building automation, access control, attendance, fire alarms, etc., need to be integrated with the CCTV system, this integration should be considered at this stage.

6. Detailed Review of System Parameters: After narrowing down the choices, various system parameters from hardware to software should be meticulously reviewed to identify key factors influencing the surveillance system.

7. Review of Available Standards: Efforts should be made to review available standards for different components of the CCTV system.

8. Technical and Economic Comparison of Optimal Solutions: Based on the technical and economic data obtained, a comparison should be made considering factors like final system cost, efficiency, quality, maintenance costs, scalability, reliability, etc.

9. Selecting the Final Solution, Product, and Company: Based on the evaluations and meetings with the final candidate companies, a suitable product and company should be selected.

10. Documentation of All Requirements: To complete the design and meet the needs, all security and end-user requirements should be documented.

11. Precise Location of Installation: The final camera locations should be tested and reviewed with security experts and end-users to determine exact placement and angles.

12. Implementation of Installation Tasks: This involves groundwork like trenching, routing, and piping for cable passage. Designing poles with specialized software and ensuring communication infrastructure and power systems are also necessary.

13. System Testing and Commissioning: All related equipment like cameras, communication systems, central software, and control rooms should be installed, commissioned, and any potential issues resolved.

14. Preparation of All System Maps and Documentation: Final maps and all project steps and information should be documented to ensure continuous, accurate project operation.

15. Preparation of System Usage Principles: Laws, structures, and usage methods should be prepared to ensure optimal system usage, and necessary training should be provided to system users.

16. Maintenance and Repair Planning: Developing a maintenance structure, strategies, documentation methods, and training maintenance staff are crucial for enhancing system reliability and stability.

17. Documentation and Updating Collected Information: Regular documentation and updates should be made to record any changes or expansions and stay informed about the latest developments in the field.

Evolution of Surveillance Systems:

This section briefly discusses the evolution of surveillance systems:

• Initially, analog CCTVs with VCRs (Video Cassette Recorders) were used, involving a completely analog system. Larger systems utilized a quad or multiplexer between the camera and VCR, allowing multiple cameras to record on one VCR but at lower speeds. An analog monitor was used for viewing images.
• Later, DVRs (Digital Video Recorders) replaced VCRs. DVRs digitize and compress video before storing it on a hard drive. Most DVRs have multiple inputs (usually 4, 9, or 16), incorporating a quad and multiplexer. DVRs offer advantages like no need for tapes and stable image quality. Some can display both live and recorded images, while others can only play stored data. Networked DVRs enable remote video monitoring using a PC and allow flexible, real-time transmission of analog camera data over a network.
• Video servers add further flexibility by enabling real-time image transmission over a network, offering benefits like remote access to images, system integration, cost reduction, and fast search capabilities for stored images.

Technical Considerations:

This section briefly examines key technical aspects of the surveillance system. Given the extensive technical details, this information should be compiled and archived in a detailed report.

Main components of a surveillance system include:

1. Camera:

   • Lens specifications (optical zoom, lens combination, lens speed)
   • Sensor specifications (sensor size, resolution)
   • Iris specifications
   • Type of image output
   • Pan-tilt specifications (rotation speed, rotation angle)
   • Housing specifications (protection level)
   • Camera housing cleaning system
   • Signal-to-noise ratio
   • Automatic Gain Control
   • Shutter speed
   • Minimum possible light
   • Night vision capability

2. Information Transmission Over the Network:

   • Use of networked DVRs
   • Use of video servers

3. Network Infrastructure:

   • Whether to use existing computer network infrastructure or a dedicated network
   • Connectivity options
   • Ethernet cable routing to cameras
   • Using wireless systems to connect to the nearest building with a network
   • Using xDSL modems

4. Central Software:

   • Requirements for image management
   • Compatibility and integration with other BMS (Building Management System) components
   • Compatibility with existing software (if needed)

5. Image Storage Systems:

   • Distributed storage
   • Centralized storage

6. Auxiliary Systems:

   • Poles for camera installation
   • Lightning protection for poles
   • UPS
   • Cable routing
   • Sound system
   • Microphone
   • Stable and controllable lighting
   • Other required inputs and outputs
   • Tampering detection system for cables or cameras

7. Control Room:

   • Physical security of the control room (fire, theft, attack, etc.)
   • Access control to the control room
   • Rest area for staff
   • Direct communication with various sections
   • Visitor registration
   • Attention to ergonomic parameters like architecture, monitor arrangement, control panel arrangement, chairs, air conditioning, and temperature

8. Remote Users:

   • Required software or hardware for remote access

Technical Highlights:

The following parameters are crucial for assessing camera performance:

• Resolution: Defined in lines, representing the number of horizontal lines, correlating with vertical lines and sensor pixels. Higher resolution means better image quality.
• Sensitivity/Minimum Light: Defines the minimum light required for an acceptable image. Real values should be calculated using specific formulas considering various camera parameters.
• Lens Speed: Indicated by F-Stop, showing how much the iris opens. Higher values mean less iris opening.
• Shutter Speed: Controls the charge time and light reaching the CCD. Standard speeds are 50 times per second for PAL and 60 times per second for NTSC. Higher speeds require more light.
• Lens Quality Factors:
  • Number of glass pieces: More pieces mean higher accuracy but more light absorption.
  • Glass absorption coefficient: Higher quality glass absorbs less light.
  • Coating quality: Influences lens performance significantly.
  • Mechanism quality: Precision and quality of the mechanism moving the lens pieces are crucial.

Network Information Transmission:

Three methods for network transmission:

1. IP-Based Cameras: These cameras have digital, networked outputs and offer many advantages over previous generations.

2. DVRs: Previous generation video servers, now advanced with network capabilities, eliminating major differences. DVRs can store images locally, unlike video servers.

3. Network Implementation: Two main approaches: using the existing computer network or implementing a dedicated network. Given the security nature of the system, the network should be reliable and secure.

Central Software for CCTV:

Central software should:

• Be highly secure.
• Offer professional management features for surveillance.
• Integrate with other BMS systems.
• Be scalable with appropriate licensing and costs considered.

Image Storage Systems:

As previously mentioned, image storage can be done in various ways, such as local DVRs, control room storage, or remote user storage.

Cabling:

This system requires various cables (power, video, data). Adhering to standards for trenching, channeling, cable type, connections, and creating a simple maintenance map is essential.

UPS:

To enhance system reliability and stability, power should be supplied by a UPS to ensure:

• High-quality power to equipment (preventing damage).
• Continuous operation during power outages (often coinciding with significant incidents).

Camera Poles:

Pole placement, height, and vibration affect image quality. Accurate location and suitable height, material, and geometric design of poles are vital.

Lightning Protection:

Given the height of the poles, installing lightning protection is essential.

Stable Lighting:

Proper lighting and automatic or controlled switching should be considered during project implementation.