Radar Solutions for Situational Awareness on Marine Vessels

Currently, human error accounts for 75–96% of accidents in the maritime industry. With a view to reducing this figure and improving safety, there is an industry-wide push for the automation of many shipping processes. For example, in 2021, the Ever Given blocked the Suez Canal for six days when human error caused the ship to ground. An estimated $9.6 billion in world trade was lost. But would this disastrous event have happened if the Ever Given had navigated autonomously?

Situational awareness – an understanding of where a vessel is and what is around it – is vital for autonomous vessels, which need it to navigate any environment, determine the most efficient route, and avoid harm. While large ships can be detected by traditional marine radars, wherever navigation is autonomous, small objects must also be detected. Small objects commonly found in a marine environment include boats, kayakers, animals, swimmers, and buoys.

At the moment, autonomous and semi-autonomous vessels achieve situational awareness via onboard sensors, such as cameras and lidar. Both of these can provide detailed information about the vessel’s environment, but only within certain operating parameters. Both cameras and lidar have limitations and leave vulnerabilities in terms of situational awareness. Both have limited detection ranges and may struggle with adverse weather conditions, such as fog and rain, and environmental interference, including glare from light reflecting from the water’s surface, or from the sun low in the sky.

Radar has a long history within the maritime industry: X-band (8–12 GHz) radars have been used on boats for decades, to measure bearing and distance from ships to prevent collisions. Marine radars are valuable for their impressive range and ability to perform in very harsh conditions. However, conventional X-band radar lacks the resolution required for use alone in an autonomous vessel, and so developers are looking to W-band (76–77GHz) radar that boasts higher resolution.

Standard marine radars are typically used to detect large objects, such as ships and coastlines. They do, however, have trouble detecting objects smaller than a few metres in size and at close range.

W-band radar is a novel sensing technique that combines the range and reliability of typical X-band marine radars with the accurate data yielded by alternative sensor solutions, such as lidar and camera-based systems. Navtech Radar employs its patented W-band radar technology as part of their market-leading solutions. With wavelengths of a few millimetres, Navtech’s sensors can achieve superb resolution, allowing developers to detect small objects at ranges of up to 500m. Radar returns are simultaneously data-efficient and information-rich: radar can observe multiple objects per transmission and detect their locations and cross-section characteristics. Navtech has been working for the last 20 years to ensure this technology is compact and affordable.

Even where autonomy is minimal, being able to understand the vessel’s local environment is extremely useful, to reduce the risk of collision. Navtech Radar complements typical marine radar with detection capability that finds smaller objects at shorter ranges (less than 500m). It does this while in all weather and lighting conditions – factors that limit the use of both camera and Lidar in marine autonomy.