Hook-on camera sensor system simplifies airborne spill detection and analysis

July 1, 2002
The world's first suspended camera system has been developed by PolyTech of Malmk?ping, Sweden, for, among other tasks, oilfield surveillance from helicopters.

The world's first suspended camera system has been developed by PolyTech of Malmköping, Sweden, for, among other tasks, oilfield surveillance from helicopters. The Shaark camera pod has been designed so that it can be carried by any helicopter equipped with a cargo hook. This design eliminates the high costs associated with the fitting and the certification of permanent camera pod installations on helicopters used for oil spill monitoring.

The Shaark system is also fully portable, so it can be deployed anywhere in the world that it is needed. Local helicopters can then be hired to carry the camera system, as long as they are equipped with an approved external cargo hook. This eliminates the need to engage specialized helicopters that have been equipped with fully certified camera pods, costing up to $250,000 to install, and for which charter rates may be prohibitively expensive. The system is expected to appeal to government departments with limited budgets that have a responsibility for oil spill monitoring.

The Shaark pod is suited to a wide range of optical and survey sensors. PolyTech has long experience manufacturing aircraft camera pods that are widely used by television companies and on all Swedish police helicopters. The pod has been developed as a cost-efficient and more flexible alternative to permanent camera pod installations as it can also be used for more general photography and filming as well as obtaining data required for survey projects. The larger versions of the Shaark also offer one or two environmentally protected electronics bays that are each capable of housing a standard 19-in. by 10-in. rack-mounted card cage.

Due to its flexible design, the Shaark can be equipped with a wide selection of internal power sources in order to provide an adequate supply of electrical energy for various payloads. In its standard configuration, the system provides 10-40 Ah at 28V from an internal rechargeable accumulator. Employing alternative power sources, such as integrated power generators, can significantly increase this figure.

Pitch, yaw, and roll stabilization

Polytech USA President Benkt Linnander believes that a Shaark pod fitted with a long-wave thermal imaging camera offers the best capability for detecting oil spills. Such cameras have the ability to provide images of oil spills that may not be visible or easily assessed with the naked eye. In addition to showing the true spread of an oil spill, the thermal imagery also highlights variations in the oil thickness.

When viewed through a thermal imaging camera, an oil spill is revealed in contrasting color. A Shaark-equipped helicopter can fly around the perimeter of the slick while logging its coordinates using a global positioning system to inform spill recovery vessels of the location. An important benefit of the camera is its ability to display the oil in lighter shades as the thickness of the slick increases. This makes it possible to assign oil spill clean-up vessels to the parts of the slick where they will be most effective.

Although the Shaark pod is a temporary installation that is fitted to the aircraft in minutes, it is stabilized to provide automatic pitch, yaw, and roll stabilization throughout the entire flight envelope of a typical helicopter. This means that it can offer all of the camera handling characteristics of a pod that has been permanently fitted to the helicopter, the most important of these being camera stability.

100 kg payload

Shaark pods are available in three sizes and are capable of carrying camera and instrument payloads up to 200 lb. The pod and its control box are easily transported in their own shipping cases and quickly deployed on the helicopter. The pod is simply suspended from a standard 20 ft sling attached to the helicopter's cargo hook. Because the pod is completely self-contained, no power or control connections are required from the aircraft. After take-off, the pod's folding landing gear is retracted automatically or by remote command from the operator, who communicates with it using Bluetooth technology radio communications link.

The radio link provides the operator with full control of the cameras and the pod, as well as its landing gear. A visual display of the camera's image can also be provided for the operator using a single-channel microwave video link wherever local certification regulations permit it. Motion sensors within the pod compensate for movement of the helicopter and enable the cameras to be locked onto a particular spot on the ground and to hold that image without operator intervention and regardless of helicopter movement. At the end of a flight, the pod automatically detects that it is within 6 m of the ground and extends its landing legs to prevent damage, thereby ensuring that the system remains intact and available for further missions.

For more information contact Toby Segerstrom, Polytech. Tel: +46 157 246 60, fax: +46 157 246 69, email: [email protected], website: www.polytech.se.

The Shaark pod, available in three sizes, is capable of carrying a wide range of camera equipment or survey instrumentation.
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