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Version 4.0

Title: CCTV Operational Requirements Manual - Is your CCTV system fit-for-purpose
Authors: N Cohen, J Gattuso & K MacLennan-Brown, Home Office Scientific Development Branch (HOSDB)
Series: HOSDB Publication 55/06
Number of pages: 48
Date published: January 2007
Availability: Download full report PDF 2MB

The manual outlines each of the 4 stages that CCTV planners should undertake when putting together an effective CCTV system. Namely,

Level 1 - Operational requirement

Before focusing on the requirement for the CCTV system itself, some thought should be given to the nature of the problem or threat that needs to be resolved. This high-level statement of the overall security need is known as the Level 1 Operational Requirement. A simple Level 1 OR checklist is given below. Detailed descriptions of each step can be found in the full guidance document. Completion of a Level 1 OR checklist helps ensure that the strategic issues are analysed first and that the most appropriate solution is arrived at, even if this requires options other than CCTV to be considered.

1. Site map
2. Statement of problem
   Threats, assets, security issues
3. Stakeholders
   Site operator, landlord, licencing bodies
4. Risk assessment
   Staff safety, health and safety
5. Success criteria
   Deterrence, maintain safety, prosecutions
6. Determine the most effective solution

Level 2 Operational Requirement

The purpose of this section is to provide a guide through the process from the decision “I need CCTV” to the commissioning of an effective system. The first and most important to question to be addressed with any CCTV system is What do I need to see? closely followed by Why do I need to see it?. 4 general observation categories have been defined, which are based on the relative size that a person appears on screen. As part of the OR development, the user will be asked to decide which of these four categories best reflects the type of activity being observed. The CCTV installer will then be able to fit a suitable camera to meet the requirement.

• Monitor and Control: A figure occupies at least 5% of the screen height and the scene portrayed is not unduly cluttered. From this level of detail an observer should be able to monitor the number, direction and speed of movement of people, providing their presence is known to him; i.e. they do not have to be searched for.
• Detect: The figure now occupies at least 10% of the available screen height. After an alert an observer would be able to search the display screens and ascertain with a high degree of certainty whether or not a person is present.
• Recognise: When the figure occupies at least 50% of screen height viewers can say with a high degree of certainty whether or not an individual shown is the same as someone they have seen before.
• Identify: With the figure now occupying at least 120% of the screen height, picture quality and detail should be sufficient to enable the identity of an individual to be established beyond reasonable doubt.

Level 3 - Technical Guidance

This section is designed to provide further guidance and background information to assist those who wish to develop a more detailed set of technical specifications for their CCTV system. It may also help those who, whilst not involved in technical issues themselves, may need to discuss matters such as camera placement or recording requirements with the contractor who is responsible for the system design and installation. The constituents of a typical CCTV system are shown below. It is important to consider each component in turn, starting with the scene illumination and concluding with the replay and review of recordings.

As with the Level 2 OR, full descriptions of each of these steps is given in the full manual.

System Validation

The final step in the process is to check that all of the functions specified in the operational requirements have been met by the installed system, a user manual has been supplied and that the system has been set up correctly. In particular, test:

• Camera’s field of view
• Live and recorded image quality
• Storage time provided by the system
• Operation of the alarms and motion detection features

It is important to check that the field of view and image quality from each camera allow you to see the target with the required level of detail (i.e. enables you to either identify, recognise, detect or monitor the target as set out in Level 2 OR). One method for doing this is to use a Rotakin test target, which is a panel shaped as the silhouette of a person, marked with resolution bars and with the ability to rotate. Further details can be found in HOSDB publication 14/95 Performance Testing of CCTV Perimeter Surveillance Systems.

Getting a copy

Download CCTV Operational Manual - Is your CCTV system fit-for-purpose PDF 2Mb

Last update: Tuesday, April 17, 2007