Securing Our Airports

Airports are high value assets of critical importance to the nation and need to be protected to obviate adverse impact on the national economy, status and morale. Airports have a large perimeter that needs to be secured in a way so as to prevent unauthorised entry failing which the system should have the inbuilt capability of speedy and accurate detection to enable appropriate and swift response by the security establishment to foil attempt by the intruder to reach his target as well as to neutralise the threat.

External intelligence may not be actionable. Bolstering the intelligence that is available in the immediate area of the airport under the command and control of the security staff that is entrusted with the responsibility can be an environment-shaping tactic as far as prevention of intrusion is concerned. In any antiterrorist operation, intelligence is the key. Electronic surveillance systems are force multipliers and advantageous to security personnel as these provides accurate information on the precise location of intrusion and the number of intruders so that an appropriate force can be deployed for timely intervention. Electronic systems reduce the effort required in terms of the number of personnel deployed for protection or the mobile patrols to detect infiltration. These systems have the ability to provide intelligent, automated, advance warning of a likely intrusion into areas of interest. On receipt of advanced warning, the response team is activated.

The Concept

The concept is based on the continuum of surveillance, acquisition/verification, assessment of the nature of threat, tasking of requisite forces and neutralisation of threat. In the present scenario, surveillance is carried out by look-out posts, verification/reconnaissance mainly by patrols followed by engagement by the response team. The quantum of force that is required to neutralise a threat is inversely proportional to accuracy of intelligence. Greater the accuracy of intelligence, lesser is the force necessary to tackle the threat.

While the force is well trained and adequately equipped, if the quality of surveillance and verification can be enhanced to the required level, then it becomes a lethal combination to deal with any threat. Surveillance and acquisition/verification being a tedious process and never foolproof, this system focuses on enhancing capability by automating the process to ensure 100 per cent detection and minimising false alarm.

The most cost-effective system has un-cooled thermal sensors for surveillance during day and night and pan, tilt and zoom (PTZ) cameras for verification during day. At night, as movement in the vicinity of the airport perimeter is restricted, any person detected by the surveillance system is regarded as a threat and response is activated.

The security system that has been envisaged will provide comprehensive, state-of-the-art and cost-effective security. The primary objective has been to provide a pre-emptive system that will prevent a disruption rather than conventional technologies that primarily provide forensic or post-event capabilities. The latest generation Intelligent-CCTV (I-CCTV) is designed for preemption and deployment in critical outdoor locations. These items have been selected to provide a cost-effective system, the biggest bang for the buck, without compromising security.

The security system needs to be a mix of men and machines. Equipment that provides pre-emptive, intelligent, automated inputs, need to be acted upon by men as in the final analysis, it is always the man behind the machine that matters. The system will be integrated through an optic fibre cable (OFC) network terminating at the security control centre. The signal feeds from the components will be analysed, integrated, displayed and archived at the security operations centre. Alarm situations will be acted upon by the security director. After verification, they may dispatch the quick response team (QRT) to manage the situation depending on the need.

System Overview

The system will consist of the following sub-systems to provide means for automated intelligent alerts and verification.

• Surveillance. Surveillance will be carried out by fixed uncooled thermal sensors with all-weather capability operating round-the-clock. They are also immune to fog, haze, smoke and can sense heat source through camouflage. These sensors will be deployed in a sentry-like-mode with a field of view (FOV) fixed in azimuth and elevation so as to cover a pre-selected area. False alarm challenges faced by conventional systems such as moving clouds, shadows, leaves, branches and animals are eliminated intelligently and only movement of human beings, vehicles and boats in the case of a water perimeter, will generate alarm. The deployment should be so planned that there is minimum blind areas in the line of sight (LoS) of these sensors.
• Verification. During day time when the alarm is generated by the surveillance sensors, a PTZ camera will be steered automatically to the correct azimuth and elevation of the source of alarm to assess the nature and size of the threat. The coordinates of the intrusion can also be made available with the exact location of individual intruders with an aerial view (Figure 1). Based on this input, the response force is tasked to deal with the threat.

Perimeter Intrusion Detection at an Airport

The perimeter that has been assumed for planning purpose is indicated in Figure 2. Any deviation will need re-planning. The suggested deployment is in Figure 3.

In Figure 3, the red icons indicate the location of fixed uncooled thermal cameras. The area covered by the yellow triangles is the footprint of the sensors and a gapless overlapping coverage is ensured. The red triangles, close to the icons are blind zones at the feet of the camera. These are covered effectively by the footprint of the camera that is behind.

The grey icons with brown rings around them are the locations on PTZ verification cameras. Since the effective range of these sensors is quite large, the number of sensors required is few and the total project cost is lower due to savings in infrastructure such as poles and power. A close-up view of one segment of the perimeter is as shown at Figure 4.

As the cameras are deployed along the perimeter wall, their FoV is arranged to cover areas both outside and inside the perimeter wall. In this arrangement, the minimum distance at which an intruder can be detected outside the boundary wall will be 20 metres. This warning is adequate for effective response as the boundary wall acts as an impediment. By the time the intruders scale the boundary wall, the team will be in a position to cordon off the area. In case enhanced early warning is desired, camera positions can be altered and additional cameras installed. The yellow triangle indicates the area within which the intruder can be tracked. Intruders cannot approach the base of any camera without the camera behind generating alarm. In this manner cross cover is provided by cameras to ensure gapless perimeter coverage.

Functional Characteristics of the System

As airports are high-security areas, it is critical to define key functional requirements before designing the solution. This requires in-depth understanding of airport security and state-of-the-art electronic security technology. With the installation of this IP based system, the following objectives are intended to be achieved:

• Early Warning Zone. The system should provide detection and alert against human and vehicle-sized intruders in a 3D zone within 20 metres on both sides of the fence.
• Reliable Alerts. The system should detect all intrusions with low false alerts, in environmental conditions ranging from clear day to all-weather and lighting conditions.
• Automated Verification. The system should provide for hands-free intruder verification and zoom-in using automated PTZ acquisition and tracking of target throughout surveillance. System should cater for automated re-acquisition and continuous tracking independent of temporary occlusions. The PTZs used should provide evidence-quality imagery.
• Automatic Tracking. The intruder needs to be automatically tracked continuously for at least 20 metres before and after the boundary wall in three dimensions for seamless handover to QRT.
• Situational Awareness. The system should provide aerial view of intruder’s location. Geo-registered coordinates should be reported along with intruder tracking information and sent directly to the QRT and control centre for quick response without human intervention.
• Multi-sensor Coordination. The system should have the capability for target-tracking using its geo-registered coordinates to enable correlation between multiple sensors including easy sensor-to-sensor handover and multi-sensor validation.
• Full-IP Architecture. The system should be standardsbased IP architecture for easier integration with other systems and operations.
• Interoperability. The system should provide seamless integration of PIDS with Security Operations Centre without middleware or custom integration.
• Scalability. The system should be capable of linear scalability without additional central processing hardware. There should be the possibility of expanding the configuration of the system by integrating a new camera or monitor, into the system. The system should be scalable to enterprise level so that it is operative at different locations seamlessly.
• Environmental Protection. Each sensor enclosure should be sealed, nitrogen-filled and pressurised to prevent moisture incursion.
• Maintainability. All equipment should be designed to ensure continuous operation for 15 years under the environmental conditions specified.
• Zones. The system’s FOV can be divided into a collection of independent zones or regions, each with the ability to specify different alert criteria.
• Analytic Modes. The system should provide the following Analytic Modes that are programmable with ease in the FOV of the sensor:

»  Time based alert policies
»  Motion zone
»  Multi-mode tripwire
»  Directional Zone violation
»  Loitering
»  To and From zone

• Target Attributes. The system should provide the following Target Attributes that are programmable with ease in the FOV of the sensor:

»  Height
»  Width
»  Speed
»  Direction
»  Aspect-ratio
»  Absolute Geo-registered Rectangular Coordinates.

Conclusion

An effective perimeter security system must have components for continuous gapless ‘surveillance’ of the perimeter, day and night, in all-weather conditions. The system should intercept hostile elements before they can attack their targets. To achieve this, the system needs to detect the entity, identify whether it has hostile intent and the magnitude of the threat. All this needs to be accomplished in good time for interception.

Empirical studies indicate that the attention span of a person watching a monitor is under 22 minutes. Registering any matter of consequence, if one is given an array of 16 camera views, is impossible. The surveillance system needs to be ‘Intelligent’ in that it should be able to weed out false alarms. It should be capable of providing automatic alerts when a target is detected so that the officer on duty is free to attend to other tasks on hand and look at the screen (Figure 1) only when an alert is sounded. This solution suggests installation of a system with intelligent, automatic, un-cooled thermal sensors as it will suit airports best. It will be all-weather with true day and night capability.