Dynamic positioning is susceptible to RF interference and spoofing without anti-jamming technology
Jamming and spoofing of positioning information is an increasing threat to vessels operating in areas of high security risk. Jamming is the disruption of electronic devises with white noise, preventing bridge systems and dynamic positioning (DP) from understanding the position of the vessel.
Spoofing interferes with electronic signals and places electronic plots, for example on ECDIS, in a different geographical place. Both are used offensively and defensively by military forces and can also be used by criminals to jam GPS devices on valuable assets.
Jamming is usually easy to implement and straightforward to detect. Spoofing is more subtle and can be undetectable, but requires advanced technology, used mostly by military forces, to disrupt, command and control systems.
According to Risk Intelligence chief operating officer Henrik Ehlers Kragh, Russia’s invasion of Ukraine and its control of those territorial waters has increased the risk from jamming and spoofing in the Black Sea.
“The situation is unlikely to get better any time soon, and in fact it may turn worse,” said Mr Kragh.
There have also been jamming and spoofing incidents in waters around South Korea in recent years and in the eastern Mediterranean.
Disrupting positioning accuracy and data system denials can prevent DP and ship navigation systems working effectively, placing the safety of operations, vessel and crew at risk.
With this backdrop, Hexagon subsidiary Veripos has expanded its portfolio of DP sensors and anti-jamming protection. Its latest addition is an extension of its advanced positioning solutions, combining data from the Global Navigation Satellite System (GNSS) with inertial navigation systems (INS) and visualisation software.
SPAN GNSS+INS uses technology from another Hexagon subsidiary, NovAtel, for robust and reliable positioning to a centimetre level.
With a GNSS+INS solution, vessels operating on DP can bridge outages in GNSS tracking and through short periods of radio frequency (RF) interference, jamming or spoofing.
“The robust positioning, heading, velocity and attitude measurements generated from a deeply-coupled GNSS and inertial solution like SPAN technology is a game-changer to DP operations,” said Hexagon autonomy and positioning division’s marine segment portfolio manager, David Russell.
“SPAN technology has a proven track record of bridging outages, enabling rapid reacquisition of signals and building a reliable and robust positioning system,” he said.
“It is an option for vessels to ensure an added layer of resiliency and achieve continuous cm-level accuracy across all conditions.”
This product builds on Veripos’ solutions for high-precision positioning of offshore support vessels and drilling rigs using GNSS and precise-point positioning (PPP) correction services through terminals, such as the LD900 receiver.
SPAN technology couples GNSS with inertial measurements, improving precision and resiliency against GNSS outages. It enables rapid re-acquisition of positioning in case of interruptions to GNSS, such as from signal outages or interference.
“A deeply-coupled GNSS and inertial solution like SPAN technology is a game-changer to DP operations”
SPAN GNSS+INS technology is compatible with commercial inertial measurement units and is scalable with existing LD900 GNSS receivers, Quantum visualisation software and Apex correction services.
A second product introduced during Q4 2021 directly addresses risks of jamming and RF interference for offshore support vessels. Veripos has developed a low size, weight and power (SWaP) model of its interference mitigation unit.
This model has GPS anti-jamming technology (GAJT) and protects against RF interference. GAJT-410MS has adaptive nulling, including jammer direction-finding and up to three simultaneous nulls for multi-jammer scenarios.
It is the smaller version of the field-proven GAJT-710MS. Veripos said it could be applied for preventing interference of DP during seismic surveys, offshore construction and platform supply. It could also be used on unmanned and autonomous vessels, which would require added layers of protection against RF interference.
Veripos said GAJT-410MS protects against RF interference, jamming and spoofing activities to enable assured positioning, navigation and timing (PNT).
This low SWaP unit is optimised for space-constrained vessels, such as those designed for unmanned and autonomous operations, and workboats requiring DP.
The power injector data converter simplifies installation by connecting the GAJT-410MS to the user’s existing GNSS receiver through a single cable.
It is compatible with Veripos LD8 and LD900 GNSS receivers and has an integrated four-element anti-jam system, which provides dynamic protection on various GNSS platforms.
These include GPS L1 and L2, the European Union’s Galileo E1 and satellite-based augmentation system SBAS L1 and Japan’s Quasi-Zenith Satellite System (QZSS) or Michibiki L1/L2 frequencies.
It provides protection against intentional and benign RF interference from nearby devices and jamming sources.
“The GAJT-410MS is an ideal anti-jam solution for users requiring the highest quality positioning, navigation and timing available in space-constrained platforms like unmanned and autonomous vessels,” said Mr Russell.
GNSS satellites and launches
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