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Practical perspectives in evaluating digital surveillance systems

I once attended a review session in a company evaluating options for a full digital surveillance system. With a new control room function being built, the time was ripe for the company to consider the move to digital, something that many other companies are considering.

This includes a fully networked system operating from a remote site with the potential use of PC monitors and digital recording devices. My knowledge of technical systems and specifications is very limited, but I was invited to attend because of my exposure to the management of different operations and human factor issues. The comments in this article in no way represent a recommendation of how digital systems should be reviewed, but reflect my own increasing awareness of some of the factors that came up in the discussions.

The first thing that struck me was that it was the IT specialist who was calling the meeting and requesting the security personnel to attend. IT had been given the mandate by the security manager to investigate and review possible options because it was felt that they were the people most suited to the task in the organisation.

This is a departure from the usual security approach, but is something that is probably going to happen increasingly as CCTV digital solutions become more common unless security departments acquire these skills or people themselves. The IT specialist also demonstrated a planned, well-considered set of criteria and system demands that were going to be relevant to an operational system. This was aimed at facilitating an objective evaluation on how well the different options and equipment would suit the needs of security personnel. I am sure many security personnel could have done the job as well, but my practical experience indicates that IT practice does bring in a structured method of evaluating systems that can benefit projects and can be used by other disciplines including security.

Different perspectives

It is also clear that people involved in reviewing digital systems approach things from different perspectives. IT specialists, engineers and security technicians all have different orientations in their view of the technical capabilities and priorities. However, it is notable that different security people can also see things from vastly differing perspectives. Some features are seen as important by some people, and not even bothered with by others. The quality of recorded video is also an issue that people take different views on, sometimes to their cost according to some sites I have seen that have gone the digital route. Because each security person was coming from a different perspective on what they were interested in, the IT specialist had to see if he could satisfy these different demands within the system. The importance of having an objective outsider to facilitate objective decision-making and to avoid group think was something that struck me as particularly useful. One of the dangers of having the senior security person determining key criteria is that people often tend to defer to him or her. The other thing that struck me is how important it is to have the different user perspectives and needs cleared up before choosing and implementing the system.

The second major impression is how the quality of digital recording is open for debate and how easily operational requirements for one aspect may get lost when considering another. There are a number of advantages to digital systems, but for me the key purpose of the system is to produce image quality on monitors that will allow recognition of incident conditions, and to produce recorded information that will satisfy requirements for a number of purposes. In the discussion, I identified four major aspects that I thought were relevant to satisfy before one could even think of the advantages of the digital system.

1. Can the system handle the data requirements from all relevant cameras at the resolution and frame rate required?

2. Is the visual quality of picture presented on monitors to operators at an appropriate quality to allow detection of relevant details, movement, and objects, and can viewing be done comfortably over a sustained period?

3. Is the quality of recorded data of a suitable quality for review and audit purposes?

4. Is recorded data of an appropriate quality to present for evidence purposes?

High-end systems

The third major impression in the discussions we had highlights the advantages that software interaction can produce with digital systems. The use of a graphics user interface to manage displayed screens or analyse and process data brings in a number of potential advantages on high-end digital systems. Features that struck me as useful for management and investigation included a variety of search capabilities and the ability to use graphics to chart utilisation, performance and camera detection issues. While not enthusiastic about matrix screens with more than one camera view being displayed simultaneously, the ability to call up configurations of screens around a specific area should there be an incident could have major advantages in seeing the presence of people and objects and where people are moving. Cameras that require little observation and where anything that occurs is very obvious, such as somebody standing at a door, could also be grouped together for space-saving purposes.

Different digital systems have different feature sets, and companies may choose to go to various extents in implementing a fully digital CCTV system. It is also one that is going to increasingly combine both security and IT input. Getting a well-planned assessment programme to evaluate the different options is going to be a critical part of ensuring the choice of system produces the right outcomes.

Dr Craig Donald can be contacted at Leaderware on 011 787 7811 or [email protected]

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