You can’t fight what you can’t see

by | Oct 6, 2022 | Blog

In recent months, tankers and ships have been behaving oddly on maritime location tracking systems in and around the Black Sea.


Vessels effectively vanish for days at a time and then show up again many nautical miles away. Couple this behaviour with the growing evidence that some of these Syria-and Russia-flagged ships are coming into European ports laden with grain, likely stolen from Ukraine, as well as embargoed Russian oil, and it becomes abundantly clear that these vessels are up to no good. But this ghostly behaviour is nothing new.

For some time now, maritime vessels have had a habit of disappearing and reappearing. Ships intentionally hide their location when participating in illicit shipping practices, such as illegal fishing operations, or obfuscating their origins or destinations whilst trafficking in sanctioned goods, drugs, arms or even people. Yet, despite unprecedented scrutiny on ocean-going vessels ferrying their cargo around the globe, these ships are easily able to flaunt international law and sanctions by switching off their Automatic Identification System (AIS) transponders – or, that is, ‘going dark’.

Turning off AIS is perceived as engaging in illegal activities

Required of ships above a certain size, AIS is an open-source tracking system that acts as a maritime navigation safety and communications platform. A wide variety of information – including, vessel identity, course, speed, position, etc – is automatically transmitted by AIS to other ships, aircraft, satellites and land-based stations. And whilst there are legitimate reasons for disabling AIS, this act is generally regarded to represent a vessel that is concealing its location and identity to hide illegal shipping activity.

Another approach to monitoring maritime traffic on the high seas is the Vessel Monitoring System (VMS), which was developed principally to track the location and movement of commercial fishing vessels in national fishing waters. The system utilises onboard transceiver units to communicate vessel position reports, which include date, time, ship identification and location. However, like AIS, VMS can also be switched off to obfuscate illegal shipping activities.
So, whilst utilising AIS or VMS data is often the default for national navies and coast guards to combat illicit maritime practices, the fact that these systems can be simply switched off or spoofed presents a fundamental weakness in the authorities’ ability to enforce the laws and regulations at sea. This means that additional, complementary tools and data are required to shed light on this glaring blind spot.

Traditional maritime domain awareness systems are insufficient

Remote-sensing satellites with cameras or synthetic-aperture radar (SAR) are excellent for imaging ships – especially at night and through cloud cover in the case of SAR – and being able to cross reference these images with AIS or VMS data to identify potential nefarious activity. They can also be used to detect signals from shipborne radar. However, you need to know where to point your space-based sensors, which is problematic if you can’t see anything to direct them towards. Moreover, it takes time to task a satellite, downlink its data and provide the necessary intelligence to the authorities. So that’s why it’s important to leverage technology that can detect ‘dark’ ships in real time without relying upon AIS, VMS or satellites.

ESROE’s Micro Electronic Support Measures (MicroESM) capability can see through this ‘dark’ maritime landscape to detect and identify vessel radar signals even when AIS and VMS are disabled. Providing national navies and coast guards with wide fields of view, MicroESM can accurately locate and identify radar emissions of maritime vessels not appearing on AIS or VMS and which are likely engaged in illegal shipping activities, thereby supporting coastal surveillance missions.

Intelligently designed to reduce its size, weight and power (SWAP) profile, ESROE’s MicroESM can detect signals in the 2-18 GHz frequency range, including lower-power radar, as far as the horizon. These findings, which can be mapped to existing signature libraries, are then displayed in real time on interactive mapping software, enabling the user to investigate detected signals and even save unidentified ones for further analysis. MicroESM’s small form factor also means that it can easily be mounted on a light unmanned vehicle – airborne or seaborne. And thanks to its low cost, multiple MicroESM units can be simultaneously deployed in an array to enable signal triangulation and exact location-finding across the maritime domain.

So, even when ships ‘go dark’, ESROE can light them up.