Security is a vital issue for any airport. One only has to make a journey by air to see the significant increase in security measures imposed on the travelling public following the high profile terrorist incidents of recent years, but these overt procedures are only the tip of the iceberg. Physical security such as perimeter fencing and barriers, coupled with electronic security including access control and intruder detection, have all combined to make airports less vulnerable. One of the biggest growth areas in this latter category of electronic security is Video Surveillance (CCTV), a growth trend which is as applicable to airports as it is to the city centres which have tended to capture the majority of the media headlines in terms of the dramatic increase in camera based surveillance.
Human Limitations
One downside of the increasing use of video surveillance is the inability of the human eye to cope with the amount of information that is now being processed. Research in the USA has demonstrated that a human observer viewing two monitors with automatic image switchover will miss up to 45 percent of all activity in scenes after only 12 minutes. This increases to up to 95 percent after 22 minutes. This has led Siemens to extensively research and develop intelligent video analysis techniques in order to help alleviate the information overload on those responsible for observing and responding to images captured on video surveillance security monitors.
Siemens Video Surveillance Expertise
Siemens Building Technologies (SBT) is a leader in video surveillance technology, with five separate research and development facilities located around the globe and a history of some 25 years in developing digital products. Much of SBT’s recent growth is attributable to the commitment to optimising solutions through an integrated approach, also being a manufacturer of Access Control, Intrusion Detection, Fire Safety products and systems, and combining these with other Siemens integrated systems which include passenger infrastructure, baggage and cargo handling and airside lighting to name but a few.
Central to SBT’s video surveillance product offering is SISTORE CX, an intelligent video codec which demonstrates the move from analogue technology to video-over-IP – the digital world where incoming video signals are digitised in real time (40 milliseconds per frame) and compressed into MPEG4 format to be transmitted over Ethernet networks with the best quality and the fastest speed. SISTORE CX integrates three devices: digital video recorder, video matrix switcher and video motion detection. As a digital technology, SISTORE CX incorporates powerful signal processors that are also capable of running incredibly sophisticated software algorithms. It is in this area of algorithms that Siemens is at the leading edge of technology, developing the means through which intelligent video analysis continuously examines the camera signals to help reduce the load on the human element of the surveillance equation.
Enhanced Detection Solution
In recognising the role that video surveillance can play in airport protection, it is important to realise that it should not been confined to terminal buildings and public areas. People can break through or climb over fences, gaining access to runways, ground equipment and service buildings. Perimeter surveillance is therefore vitally important to maintaining effective security in airport applications.
Identifying people and objects quickly and reliably is the central requirement of a video surveillance system. Inside terminals, restrictions can be placed to ensure passengers stay inside secure cordoned areas, with an alarm generated if the pre-defined boundaries are crossed and somebody moves into areas where public access is forbidden. With SISTORE CX this is achieved through SISTORE CX EDS (Enhanced Detection Solution) which adds a professional video motion detection option to the system’s video streaming and recording capabilities. EDS is added via a software module and includes object and people tracking. EDS is based on a sophisticated algorithm, employing a statistical method analysis that actually monitors an object to build intelligence, continuously analysing the video to ensure the object being tracked fulfils the exact criteria for a true alarm.
The immense processing power of SISTORE CX EDS enables over 30 billion computations to be processed every second, using a series of different measures to ascertain if the object being detected should trigger an alarm. ‘Trip wires’ are set, either singly or in multiples, within the field of view of the camera, usually along a perimeter or an area where objects should not cross, such as the terminal interior example alluded to above or along perimeter fences. Motion arrows can be added to ensure movement is detected in the specified direction. Where standard trip wires cannot be set, normally when the camera is viewing the façade of a building such as the terminal, dynamic trip wires can be set. These features of the algorithm, coupled with object speed and size and perspective compensation, ensures not only the highest detection rates but also the minimising of false alarms due to environmental factors such as rain, snow, wind, shadows, animals and trees.
Object Detection & Removal
Over recent years, terrorist attacks have also been caused outdoors by abandoned cars and trucks or indoors by abandoned boxes, bags or luggage.
Another feature available on SISTORE CX is abandoned object detection, another immensely useful feature in an airport security surveillance application. Again available via a software module, this algorithm provides the means by which unattended items can be detected. The most obvious application and one that is critical in an airport scenario is identifying a potentially explosive device. However, this feature has applications beyond identifying unattended objects, as it can be used to keep designated areas clear of obstructions. In the case of an airport terminal, this could be used, for example, to keep the all important fire exits clear.
Ongoing Development through Algorithms
Video surveillance will remain a central feature in airports’ ongoing vigilance against security threats, particularly given the technological developments which support and enhance the observer’s ability to respond to those threats. Siemens are at the forefront developing the algorithms that are set to play an increasingly important role in this process, providing the sophistication, reliability and immunity to false alarms that will enable video surveillance to continue to develop as an integral part of the security equation.