Safeguarding Satellite Services in the Maritime Industry

Every day, an innumerable number of vessels, including oil and gas rigs, rely on satellite communications for essential operations. As most of those reading this will know, the importance of these services cannot be overemphasized, whether it’s keeping crew members connected to families back home, to infrastructure monitoring, production, weather information and most seriously, safety. These applications rely on satellite services, the lack of which would seriously effect both the safety and comfort of a vessel and its crew. 

On the part of the satellite operator, a considerable amount of work goes into keeping satellite spectrum free from interference, most of which goes unnoticed by the maritime industry. As such, many tend to assume that satellite interference is not a worthy topic for discussion. But interference in this sense can either mean a serious degradation in the quality of the service, inaccurate or partially available monitoring systems for example, or in some cases the complete loss of some services. 

When interference does strike, it is often seriously disruptive but also dangerous, given the importance of those services reliant on satellite networks. 

The Challenge of the Maritime Environment 

As a vessel travels from region to region, the satellite terminals installed on board need to change from one satellite beam to another in a process called repointing, to ensure continued coverage. Some satellite terminals can be programmed to do this automatically but in some cases, manual intervention is required. At this point another element is introduced, that of human error and that, in turn, can only increase the chances of incorrect alignment and sadly this is too often the case. 

Interference caused by any Comms-On-The-Move (COTM) service (those designed for moving vessels, vehicles or similar mobile uses) is distinctly different to that of a fixed service. If you picture the rolling action of the sea, or a military vehicle speeding across rugged terrain, the satellite terminal on the vessel or vehicle is subject to constant jarring, highly random movements meaning they are rarely ever immobile. This makes pinpoint accuracy absolutely essential to ensure continuous pointing accuracy to a satellite, which in turn keeps the service locked. 

Sadly, a barrier to ensuring accuracy often presents itself in the form of poor-quality equipment. The margin for error within the maritime space is so low that antenna pointing must be spot on. But despite the best efforts of the ship operator, if the terminal/antenna is already incorrectly designed, or the degree of curvature of the dish is out by just a few millimeters, the beam will align with the wrong point on the antenna, potentially reflecting towards a wholly different satellite. The battle is essentially lost before it has even begun. 

Prevention is Better than Cure 

As the location of COTM terminals are always moving, it can be challenging for a satellite operator trying to identify the source of an interfering transmitter. For fixed terminal interference, geolocation has been a successful tool in significantly reducing the time to resolution. In other words, measuring the signal received by adjacent satellites to calculate the rough location of an interfering carrier. However, new technology, including the innovative use of drones, is actually making it easier to track the interference if the antenna is moving. With these technologies, the very fact the antenna is moving makes the process more accurate.  

Often it is difficult for crew on board a vessel to work out if it is their equipment causing the issue in the first place, or if the interference originates from elsewhere. As a result, significant time may have passed before the incident is even reported to the operator. Even after the problem has been acknowledged, resolving one incident of interference takes time, and any time to resolve can significantly disrupt the operations of the vessel. 

Given the difficulty solving maritime satellite interference when it strikes, the most practical way of reducing the effects is to prevent it happening in the first place. The accuracy of terminals is central to correct alignment of antenna, and if vessel operators fail to use good quality equipment, they will always be fighting a losing battle. 

Conclusion 

The situation is challenging, but technological developments have and continue to point to a promising future. At our most recent workshop, we heard from QuadSat, an organization currently developing drones capable of testing antenna performance of ‘as installed’ COTM equipment at any location, including at sea. For example, by reducing the need for vessels to dock in port, the drones, if successful, should increase the number of vessels taking the time to test installed antenna performance, therefore reducing the chance of incorrect alignment.

Whether it’s reducing errors using automation or investing in good quality equipment from manufacturers committed to reducing interference, it makes sense for vessel operators and the wider maritime industry to keep interference in its sights and take all the precautions it can to mitigate or eliminate, given the expense and manpower wasted on resolving incidences, this can only benefit all by reducing the cost of services provided.

Martin Coleman is Executive Director of the Satellite Interference Reduction Group.