VTS equipment is rapidly evolving following trends set in onboard navigation systems as well as trends expanding from other sectors such as the military and air traffic management.
Traffic image
Today it is common for a traffic image to consist of a fusion of many different sensors including radar, AIS and other Hydrographic and Meteorological sources.
In particular, AIS has revolutionised the way in which VTS interacts with traffic. In the past VTS would have been aware of a vessels approach only by a raw radar return on the traffic image prompting questions such as “Who is this?”, “Where is she bound?”, “Will she cause me trouble!” AIS now provides VTS an advanced insight into the vessel, enabling a VTS to prepare for the vessel in terms of advance traffic management:
- Is the berth ready
- Is the pilot ordered
- Is the vessel early or late
- The vessel will need to be directed to anchor
- The vessel will interact with other vessels at a later stage.
AIS also gives VTS an insight into the vessel itself. Information from the bridge of the vessel such as heading and speed data gives VTS a near real-time insight into the actions of the vessel, which is vital in terms of traffic management and navigation assistance. The close VTS integration of AIS and radar serves to perform a quality management function. Received AIS signals can be correlated against VTS radar which readily identifies problems with either AIS data or VTS radar. A VTS should actively challenge vessels transmitting defective AIS signals to ensure correct information is presented. In recent years, the quality of AIS signals has increased significantly to such an extent that in many cases AIS is a primary tracking source for VTS systems.
AIS has also enabled a VTS to hold a traffic image where it is not practicable or cost effective to install radar systems. AIS carriage has been mandated in city centre and inland waterways in the UK and Europe, where radar coverage would be expensive or impracticable. Such AIS networks enable the provision of a high quality VTS to increase safety and efficiency in often busy and restricted areas of waterway.
A significant impact of AIS has been the provision of a mobile traffic image onboard vessels giving the mariner significant situational awareness through the provision of a localised traffic image. Although this can never replace the full role of a VTS, the provision of greater and higher quality information onboard reduces the volume of VTS communications required, particularly in the provision of routine traffic information. This, as a consequence, results in VTS communications being related to the provision of essential information, which may not be readily apparent to the bridge team. AIS is still an under-used resource. The data transmission properties of the system can be further enhanced to facilitate the transmission of other navigational information such as tidal data, weather data and other text-based information. This is already be exploited in city centre and inland waterways where passenger numbers, tidal data and lock scheduling information is being transmitted successfully by AIS, thereby reducing further the VHF loading on VTS frequencies.
CCTV and VTS
Modern CCTV systems are routinely integrated with VTS equipment being configured so that is integrated with radar and AIS tracking. This enables VTS operators to select the point or vessel of interest with a simple mouse click on the traffic image, the CCTV then automatically pans to the desired point or vessel of interest. Often, in the case of a vessel underway, the CCTV has the ability to automatically follow the vessel, handing over to the next available camera in range at the appropriate time.
As offshore infrastructure is developed it is common place for radar installations to be placed on offshore wind farms or other infrastructure to provide localised surveillance to mitigate against the risk of any interference to shipboard radar. VTS radar is continuing to evolve with the introduction of new solid state ‘HD radar’ technologies developed from military applications enabling enhanced surveillance, particularly with the identification of smaller vessels coupled with lower running costs and increased reliability.
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