Site security: the CCTV supplier’s perspective

Protecting large, high value assets on oil and gas sites is essentially about establishing an impenetrable perimeter using a combination of high end systems including fencing systems, microwave barriers, CCTV and access control systems. To achieve maximum effectiveness, all the systems employed have to be integrated seamlessly and work together perfectly without compromising the capabilities of any one of them. Together they have to deliver all relevant data, from whatever source, instantly to the user in a readily understandable form. The whole integrated system has to be capable of surviving serious mishaps and failures while still continuing to be fully functional and available to the user 24/7.

For the CCTV manufacturer and system integrator the major specific challenges fall into three areas, achieving seamless integration, continuous availability and reliable intelligent assistance. Given that the way these are met can make a significant difference to the performance of the whole installation, this article highlights some successful current approaches in these three areas as well as introducing some other new performance-enhancing developments made possible by the impressive digital processing power available in the latest CCTV platforms.

Integration

In an ideal world all security equipment would use the same proprietary communication standards and operating philosophies so that each system could communicate directly with each other and all could naturally work together in perfect harmony. However in the real world there is a diversity of protocols and philosophies so a fundamental challenge in system design is how to make different types of security equipment communicate with each other perfectly and work together in complete harmony. The best solution is to use software to generate a new universal environment for all security system components and a new unified interface for humans.

This so-called ‘security management software’ (SMS) uses standard TCP/IP protocols, runs on conventional computer infrastructure with client/server architecture, and provides software interfaces for security solutions of all kinds. In effect it provides all the interpreting services needed for two-way communication between each of the different peripherals and the system’s programmable logic controller (PLC), the system’s decision-maker. It also ensures that the operator is given a global view of all the sensors and actors present in the installation as well as control over them.

But SMS capabilities do not stop there. It manages user rights, and scheduled activities. It controls the execution of complex, automatic procedures involving a large number of different sub-systems and interfaces across the whole site. It enables the PLC to log all activities in a database for future analysis, and it selects and compiles the data for the event summaries, relevant pictures and pre-history reports which it presents to users instantly via the graphical user interfaces in a readily digestible format.

The distributed client/server structure of the software allows for sub-systems to be located wherever is most advantageous, and supports an almost unlimited number of users and workstations, each with a customised client GUI. Also, importantly for handling critical incidents on large sites, it enables the simultaneous handling of multiple alarms and alarm responses.

SMS can turn complex, restrictive structures into open flexible environments. An SMS like Geutebruck’s GeViSoft with a large number of interfaces makes it easy to introduce new systems and developments at the outset or in the future, so it increases the system flexibility and the useful life of devices and systems. And crucially, by eliminating compatibility problems, it allows planners and designers to choose equipment solely on the basis of best performance.

Also in the case of GeViSoft, it even includes a specialist computer-aided software design function for direct configuration of security scenarios, ensuring that both system and GUI are tailored to the specific situation, so operation is easier, more understandable and intuitive, enabling both system and security staff to be more effective.

24/7 availability

For a security system to achieve 100% performance and 24/7 availability it needs not only hard- and software redundancy, but also the automatic management capacity to handle malfunction situations effectively. This is why GeViSoft includes a redundancy module which provides software duplication as well as intelligent monitoring and redundancy management functions. It enables multiple servers to manage multiple software clients, and all servers to observe each other. The instant that any fault is detected, the relevant functions are transferred from that component to another so that individual failures, be they software problems or hard disk, power or processor failures, do not lead to a reduction in system performance.

Intelligent filtering

Where large numbers of cameras and other security detectors are employed, reliable automatic discrimination between real risks and other spurious alarms is crucial if the security staff are not to be burdened or distracted by unnecessary system-generated events.

Traditional high-end video motion detectors have a proven track record in securing high security sites and are extremely efficient at detecting movement in specified zones and very good at eliminating the effects of global environmental changes such as those caused by weather or mast movement. On the other hand, the much newer and much vaunted software technology of video analytics is good at recognising different kinds of specified objects in a video scene. At Geutebruck rather than choose between them, we have produced a new class of detector which combines video motion detection with video analytics to exploit the strengths of both technologies in identifying threats more accurately and avoiding a large proportion of the unwanted alarms generated by other single technology systems.

The logic behind this approach becomes clearer if we look at each of the systems.

VMD

Video motion detectors detect and report motion in predefined areas of a camera image. They work by analysing the composite video signal from the CCTV camera, or to be more precise, they analyse an electrical representation of the instantaneous grey shades in the picture and monitor this for changes in brightness or contrast. In a picture from a fixed camera and in an environment with fixed illumination, this change can logically be deduced to be the result of activity in the scene. However, a VMD designed for outdoor situations where light levels and other conditions vary widely has to have a few important extra sophistications which eliminate benign environmental changes while enabling the detection of potential threats.

First, its sensitivity has to be very high to enable it to detect low contrast intruders in front of equally low contrast backgrounds, and to be able to analyse each individual detection zone in the scene for the subtle differences caused by environmental changes. Comparing results across the whole image is what enables the VMD to deduce which changes are global, and therefore benign, and which are localised and more likely to represent a hazard. Second, the VMD has to compare and store information from successive images from the same camera fast enough to ensure that a fast-moving target is captured within the operating cycle while it passes across the scene. And thirdly, the VMD has to enable the user to set up small detection zones in the far field which are much more sensitive than those in the near field. This is to counterbalance the fact that any target naturally appears larger, and causes more signal disturbance when it is near the camera, than when it is far away.

Video analytics

Video analytics is the technology of using intelligent software to filter and manage real-time CCTV video. Here it is the pixels in the whole video picture which are analysed. The software continuously analyses the scene and deduces for itself the basic underlying model, then constantly updates it for global changes such as weather and lighting. Current pictures are continuously compared with the updated background model and any unnatural changes are compared with the user’s target specification. The user can specify the target objects by their likely size, speed, direction of movement and status, and he can link their properties. The system can recognise ‘person ’, ‘car’, ‘fast’, ‘slow’, ‘wrong direction’, ‘object appearing’ and ‘object disappearing’, separately, or only when logically combined with each other. This enables the system to trigger alerts when a person moves fast, or a car goes in the wrong direction, but to ignore a car going fast or a person going in the wrong direction. The user can also define different areas of interest in the scene and associate them with different target characteristics and alarm response behaviours.

Separate but together

When both detection systems are run independently to monitor the same scene, their output can be logically combined so that an alarm is only passed on to the operator when the precise pre-determined criteria for both systems are met at the same time. This means for instance that even if a bird triggers a VMD alarm because it meets the system’s movement and location criteria, it does not match the VA’s specific size threat criteria, so no combined system alarm is issued. And, on the other hand, if the wind deflects foliage and deceives the VA into registering the shape of a person or a car, the VMD does not react, so no alarm is reported.

When VMD and VA work together their strengths are exploited and their weaknesses reduced. Each system alone would probably produce a small, but (possibly highly) undesirable number of unwanted alarms. However with the Dual-Sensor detector, Geutebruck has proved in practice that two finely-tuned, compatible systems can get very, very close to the ideal situation of no unwanted alarms. The first of its kind, this software-only product was developed to run on the GeViScope CCTV platform where each video channel has its own digital signal processor, so there is capacity and flexibility to carry out whatever individual signal processing is desired.

Other innovations in software and signal processing

As well as the Dual-Sensor, several other new software-based performance-enhancing CCTV processes are supported by the DSP technology used in the GeViScope: MPEG4CCTV, dynamic live streaming, and fading long term memory for instance.

MPEG4CCTV is an MPEG4-type encoding system which has been specially designed to generate large numbers of different video-audio channels simultaneously. It uses variable quality and variable compression to achieve this without overstretch at high loads or speeds. The user defines the desired image quality (including the GOP sizes) for each individual recording and each individual (simultaneous) live streaming channel from each camera ­– whether analogue or IP (or megapixel). The encoder than maintains this while changing the frequency of reference frames automatically in real-time, depending on the amount of movement in the picture, the motion in selected areas, other event triggers and any scheduled routines. Not only does MPEG4CCTV minimise data volume, bandwidth and storage costs, but it has such a low latency (120ms) that it can be used to control fast dome and PTZ cameras, while users enjoy smooth, multi-camera synchronised playback, forwards and backwards at any speed (from 1 picture/10s to 25fps and even image by image), and can jump back seconds or minutes to view sets of synchronised recordings.

The new ‘dynamic live streaming’ (DLS) process feeds back information from the display PC software to the compression hardware, about what window size and format the viewer currently requires for each channel. This enables the encoder to match all the live channel picture data precisely to the needs the current display windows. It is significant because in the average control room this reduces the live stream data generated by about 50% without any perceptible loss of picture quality. And, since less data means less bandwidth and less processing for display servers, it now only takes one server running Geutebr ü ck’s display software on a Core2Duo processor to supply 100 screens with live MPEG4 video at 25fps, and that means hardware savings.

The new ‘fading long term memory’ process reflects the fact that some types of recorded material are really only likely to be needed in the short term, whereas other types need to be retained for a month or more. Using FLTM the user can define how a three-stage overwriting process should be applied to different types of recording. So for example permanent real-time footage might be retained for a couple of days, then ‘thinned down’ to 6fps, then after a week reduced further to 1fps or to alarm footage alone until the full recording cycle is up. With this gradual process the user retains all the benefits but makes enormous storage savings.

Sales enquiries please to:
Carmen Lahr
Geutebrück GmbH
Im Nassen 7-9
Postfach 49
53578 Windhagen
T: +49 2645 137 0
F: +49 2645 137 999
E: carmen.lahr@geutebrueck.com
www.geutebrueck.com

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