Cruising The Data Waves

25 May 2023

Using AIS data for open source Maritime Surveillance
Earlier, we published Wings over Europe where we took a look at military air traffic using open source ADS-B transmissions. This article will be a follow up to this, focusing on the usage of AIS transmissions to track shipping. Lets get to it.
Data Sources:
AIS transmissions are similar to ADS-B aviation transmission with a few distinct differences. Despite being a VHF band transmission that usually allows for good propagation our AIS broadcasts suffer from a few distinct issues that inhibit their abilities to be received at long distances. Firstly if we consider the radio spectrum, we should know that VHF and above are generally considered usable via Line of Sight only. Unlike High Frequency transmissions where propagation can be global, VHF requires favorable atmospheric conditions known as Tropospheric Ducting to be able to propagate beyond line of sight. While these conditions can be used to send a low power signal thousands of kilometers, the conditions required for this are too inconsistent to be relied on for regular transmission.
The second issue our AIS signal faces when trying to travel over distance is the height of the transmitting antenna. Whilst Cargo Ships and other large vessels may have an acceptable position for the transmitting antenna, most vessels will find they are closer to sea level, making it harder to move beyond the horizon. Unlike land stations, where receivers can be placed in high, favorable locations these stations at sea level are unable to do the same. This means that on the high seas AIS reception via satellite is King, with many AIS equipped receivers in low earth orbit, equipping government, communication and even amateur satellites.
With all this considered, this means that tracking vessel movements can be considered more difficult than tracking aviation movements. This means that today, we’ll be using a Browser Based, AIS tracker. We’ll need one that has the ability to show AIS positions via satellite, but can also filter traffic for us so we aren’t overwhelmed by irrelevant traffic when we’re browsing.
Our choice for today will be If you’d like to browse on your own, you can find them via this link.

VesselFinder provides reliable AIS positioning information worldwide.
When we open our home page, we see the filter button below the star. Like our ADS-B article, today we’ll look at military traffic only. However you’ll also see other sorting options. We aren’t sure what we’re looking for today, so we’ll keep the rest of the sorting options open. Let’s have a look and see what’s there.

We can also sort by flag country, beam and much more.
Our first ship shows the ability of AIS transmissions to be filtered or excluded, similar to the way ADS-B is via third parties providers. We see here we have a vessel belonging to the French Navy, however we see little additional information regarding this. Searching via MMSI is unsuccessful. Possibly a Frigate?

French Navy. No tonnage, IMO number or Weight information.
Lets see what other Ships we can find.
Our next vessel is off the coast of Latvia. It’s a Latvian Warship, pennant P-09. Let’s ask Chat GPT what sort of vessel that is.

Warship P-09 off the Latvian Coast.
Input: Tell me about the Latvian Warship P-09
Output: The Latvian Navy’s patrol boat designated as “P-09” belongs to the Skrunda-class patrol boats. These vessels are designed for maritime security and patrol operations in Latvian territorial waters. With their compact size and versatile capabilities, Skrunda-class patrol boats are well-suited for a range of missions, including maritime surveillance, border control, search and rescue operations, and law enforcement tasks. Equipped with advanced communication systems and navigation equipment, the P-09 and its sister ships in the class play a vital role in safeguarding Latvia’s maritime interests, ensuring the safety of its waters, and supporting national security objectives.

Danish Warship. Frigate F362 is HDMS Peter Willemoes, an Iver Huitdfeldt Class Frigate.
Our next asset is the Danish Warship HDMS Peter Willemoes. It’s Frigate classification understates it slightly as this ship carries both Mk41 and Mk56 VLS Arrays capable of carrying the SM-2 Standard Missile and RIM-166 ESSM. With Twin torpedo launch stations and a pair of Oto Malera 76mm Naval Guns, this vessel is well equipped to fight in the missile age.

The Black Sea is as you’d expect it to be.
We notice when we move across to the Black Sea that we see little Military traffic, with most movements attributable to Turkish assets. We did find one ship flying the Russian Flag. The GRIGORY KASHTAKOV, with limited other information available. Whilst we didn’t find a huge amount in English, we had some good success using Russian Language sources where we were able to find some actual specifications as well as a picture of a sister ship. Based out of Novorossiysk, the ships appear to be a Salvage Type vessel.

Notice anything Funky???
If we take a look at our sources, we see the name presents differently to our AIS information. However crosschecking our MMSI number confirms we appear to be looking at the right vessel. A good example of how OSINT can require looking beyond traditional sources to obtain the information you require and more importantly how some information may be presented in a way in which we do not expect.

P-233 is HMS TAMAR, a United Kingdom River Class Offshore Patrol Vessel.
Moving over to Western Australia we see an interesting ship. We see P-233 a River Class Patrol Vessel belonging to the Royal Navy. Moored at Kwinana, Tamar is lightly armed, carrying little protection for Air Defense, however the Batch 2 River Class does carry aviation facilities allowing for helicopter deployment.
Applying our open source search skills to HMS TAMAR, we find a press release from the UK Government here that allows us to see that this is a bit more than a port visit.

Permanent Deployment. Royal Navy assets are now rotating through the indo-pacific region.
We find in this release that Tamar and other Royal Navy assets will be deployed in the Indo-Pacific as a result of the latest UK strategic defense review. Whist TAMAR is a lightly armed warship these deployments will also extend to the Royal Navy’s aircraft carriers as well.
Indonesian Navy
The Indonesian Navy has gone through significant reform of late, with the expected acquisition of several more assets in to the future. They’ll provide the material for the last ship of our article, the Hospital Ship KRI RJW 992.

Indonesian Navy hospital ship. Showing a build date of 2023.
Using our open source screenshot, we see that the ship appears to be relatively new with a build year of 2023. Lets apply our search skills and see if that’s accurate.

Press release from the Keel Laying, 2019. Source: Baird Maritime
Quickly enough we find a press release from 2019 celebrating the keel laying of the new Hospital ship. Indonesia, being an Island Archipelago relies heavily on maritime assets not just to project force and protect it’s waters but to provide disaster relief and assistance to its civilian population as well. We see this reflected in the type of assets operated by the navy, which include multiple LPD’s. Whilst of significant military utility, these ships are also able to be used for disaster relief as well, providing immediate aviation and medical facilities able to be used in pop up capacity during times of need.
AIS and Security
As we close today’s article we thought it prudent to touch on a relevant point. The integrity and security of AIS as a system. Any RF based system comes with the inherent ability to be spoofed, manipulated or denied and we feel it’s important to discuss this as part of the limitations around open source intelligence. Whilst spoofing attacks are rare, multiple nation states have still been caught out spoofing the locations of their warships.
Whilst being “dark” on AIS should be tactically expected, the ability to spoof the location of a warship during a time of elevated tension or conflict may come with significant advantages. Whilst the scope of this is far beyond the close of this article, if this topic interests you, you can read more about it in this popular mechanics article here that describes location spoofing of western naval assets.
Thanks for reading. We hope you’ve found the exploration of AIS traffic to be as interesting as Wings over Europe. Good luck on your own open source searching and if you see something interesting be sure to drop me a comment.
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Good article 👍
Is there a way to look at rail traffic similar to aviation and maritime??
Great piece