Portsmouth based Autonomous Surface Vehicles (ASV) Ltd, designs and constructs rugged, reliable and effective unmanned marine vehicle systems for commercial, government and military customers. A long term customer of Wood & Douglas, ASV has been deploying Orion radio data modems for over-air protocols to ensure speed and data link integrity for the control of its range of fast and highly manoeuvrable boats which are deployed as targets for naval gunnery training.
Extending vessel capabilities beyond that of target drones, ASV began developing and producing more advanced unmanned naval vehicles for training, Mine Counter Measures (MCM), Intelligence, Surveillance and Reconnaissance (ISR), and marine exploration. The complexity of these vessels and their potentially difficult roles demands pinpoint control and reliability for features not normally available on a target drone, including real time video and rugged telemetry for command and control at long range. The communications package ASV needed would have to be cost effective, lightweight and easily deployed across a range of vessel configurations, boasting the best power and antenna options for optimum use of bandwidth at sea.
ASV again chose to work with Wood & Douglas, which devised an ISR package that could address issues of connectivity, size and power consumption in a reduced, yet rugged payload. Using a highly robust and resilient combination of data and Digital Video for Moving Objects (dVMo), Wood & Douglas developed a command and control system capable of delivering video from the unmanned vessels to a fixed point, either an onshore command and control centre or mothership operating at ranges of up to 12 nautical miles from the ASV.
Deploying dVMo for high quality digital transmission, with COFDM modulation, the ASVs are able to avoid much of the interference issues that challenge analogue systems, such as rough seas, fading and re-propagation from larger vessels which can result in poor video image quality. Wood & Douglas’ dVMo uses two receivers to compare and select the best quality video data packet, which is then passed through digital signal processing (DSP) techniques to ensure high quality performance from the radio link. The use of a diversity receiver enhances the effectiveness of the hardware, allowing high quality video, audio and data signals to be carried via radio for naval applications. The unmanned vessels can each be equipped with up to four multiplexed cameras, with full pan, tilt and zoom capability to assure a complete surveillance field of vision.
The video and sensor data is then routed back to the command vessel, delivering target surveillance as well as improved visibility for accurate control and deployment of the ASV. The system also supports distributed control, enabling a mothership to hand off control of the ASV to a closer secondary vessel, or to the safety of a shore based control centre for operations such as harbour and coastal security patrol.
• Rugged, cost effective, flexible control for naval unmanned vehicles
• High quality video transmission for vessel control and surveillance operations
• Long range operations in a complex, typically radio unfriendly, environment