In 2012 the US department of Homeland Security claimed border apprehensions were down 79% percent since 2000, but such figures were quickly cited as meaningless. Were fewer people really crossing or were a larger share of those who do cross being missed? Locals claim the situation has worsened with illegal activity relocating from urban areas to the border’s difficult to monitor rural areas dotted with canyons, valleys and mountains.
Despite being faced with thousands of miles of potentially uninhabited and varied terrain, including coastal waters, border authorities are tasked with detection and prevention along these sometimes barely discernible lines. The role of border authorities around the world is to facilitate the flow of legal immigration and goods while preventing the illegal trafficking of dangerous people and contraband between ports of entry, year round and in all weathers.
A major activity is ‘line watch’, surveillance operations conducted on or near international boundaries to prevent illegal entry and smuggling. Line watch seeks to detect changes in the terrain which suggests the passage of people, animals, or vehicles, enabling the interception of those who do enter illegally before they can escape from border areas.
To successfully line watch extensive borders authorities rely on the deployment of video surveillance and electronic sensor alarms placed at strategic locations. Unfortunately securing live video feeds over long distances is a power hungry process, quickly draining batteries which then require regular maintenance. Regular maintenance makes it easier for illegals to identify camera positions and avoid them, or worse target border authority staff replacing batteries in more remote and potentially dangerous locations.
As a result border surveillance systems still predominantly capture still images from a fixed camera when a ground sensor is tripped, with the image sent to the control centre for interpretation. This proves limiting as cameras can be tampered with, rotated away from the border or simply avoided.
What border authorities need is:
- a flexible system which can be covertly installed and maintained
- long operational life on a single battery charge
- SD or full HD video when a sensor is tripped
- remote control of the camera viewpoint to seek and track in real time
Wood & Douglas extends the coverage capability of existing video surveillance systems by delivering a wide area integrated video link and telemetry control system for SD or HD Digital Video designed for operation in high risk areas.
The COFDM Video Network for Sensor Systems is a network of highly portable wireless linked cameras using a low power telemetry mesh network and secure COFDM (Coded Orthogonal Frequency Division Multiplexing) digital video transmission technology to provide enhanced link performance. COFDM is deployed for its ability to overcome multipath effects where obstructions such as canyons or buildings can cause ghost images on screens in the border control centre.
The system is comprised of a wide area network of sensors – connected via telemetry mesh radios – and multiple hidden cameras which are positioned to monitor the areas covered by the sensor network.
Two types of camera system are employed, a short range unit (SRU) and long a long range unit (LRU). As well as sensor controllers for automatic operation, all the units have GPS location onboard so that operators can easily review deployment and if required, identify relevant camera transmitters to turn on and monitor with manual telemetry control when a sensor detection is received.
Operating with a shorter range, the SRU delivers longer battery life, which helps to reduce disturbance by maintenance crews.
As well as supporting local camera input, multiple SRUs can connect with others and then act as repeater stations transmitting multiple video feeds back to the border control centre. As frequencies available can be limited, the control system will automatically allocate a frequency to each of the camera transmitters from a selection of radio channels allocated to the system. The larger the number of these channels available, the greater the number of simultaneous video signals which can be viewed at the border control centre.
SRU camera units that have been triggered by a sensor send images back over the main radio connection to the master base station and onward to the border’s surveillance control room. The SRUs relay video and the analog signal is converted to COFDM at the LRU before being sent back to the control room for analysis.
When terrain prevents line of sight connectivity between the LRU and the control centre a digital repeater station can be deployed to ‘hop’ the transmissions, extending the range while ensuring connectivity in the most challenging border landscapes. This means the control room can be safely located up to 50kms from the LRU, itself up to a kilometre from the SRUs which are located at or close to the border depending on the terrain.
The system is extremely dynamic: assets can be moved from one location to another, sent for service, or added to a new group, all totally under the control of the operator via the mesh network.
The system allows an operator to manually command the remote cameras and view surveillance images over wireless from the area around the LRU, with the operator given full camera control via a return wireless link for pan, tilt and zoom on any selected camera meaning once tripped, live camera feeds can track illegal activity at or moving across the border.
- Quickly deployed, multiple camera, wide area digital video surveillance network with mesh sensor and telemetry control network
- Covert installation and long battery life reduces tampering and danger to maintenance staff • GPS positioning
- Digital repeaters for extended range, full remote command and control at ranges up to 50kms from the border zone
- Automatic or manual control of cameras when sensors detect movement