How sonar technology can safeguard your navigation when GPS signals go awry
Though the topic of GPS disruption in the media has mostly been focused on its impact on aviation and its use in defending against drone attacks, such disruptions can also greatly impact marine navigation. The Ukraine war has brought the topic to light; various websites now offer regularly updated maps of GPS disruptions.
To better understand the concern, GPS disruptions generally fall into two categories: jamming and spoofing. Jamming is a basic attack where signals are flooded with noise, making it hard for GPS to work properly. Spoofing is more advanced, involving sending fake GPS signals that trick a receiver into believing it’s in a different location. In some cases, the attacker transmits locations that are obviously fake. For example, in April 2024, a spoofing attack made over 100 cargo ships appear to be at Beirut Airport.
More dangerous spoofing attacks are subtle, slowly dragging a ship off course without the crew noticing, potentially leading the vessel into hostile waters or run them aground on rocks or sandbars. In 2013, motor yacht White Rose of Drachs participated in an experiment to evaluate the difficulty of carrying out a spoofing attack at sea. The test resulted in “tricking” the vessel onto a parallel track hundreds of meters from its intended route.
Having multiple tools aboard to recognize anomalies is the best defense. Using GPS in conjunction with traditional nautical charts can improve yachts’ abilities to detect navigational threats and anomalies caused by disruptions. Additionally, the use of Argos 3D Forward Looking Sonar (3D FLS) gives users another layer of protection, providing real-time information of what is ahead under the water. FarSounder’s Argos sonars include a chart overlay display, which allows users to see where the historical chart data and real-time 3D FLS data correlate and, more importantly, don’t correlate. Even if GPS spoofing is not detected, a mismatch between what the sonar detects versus what the chart shows alerts users to the navigation threat.
One can anticipate that GPS disruptions will continue, and adapting operations for a GPS-denied environment concerns not only the military but also civilians.
Cassie Stetkiewicz is the director of operations for FarSounder. farsounder.com