The Russo-Ukrainian War has catapulted Electromagnetic Warfare (EW) to prominence. It is a major cause of Ukrainian drone losses, making them to lose control or miss their target. Yet it is hard to grasp, in part because it is invisible, a silent unseen hand knocking drones out of the sky.
This analysis unhides some of this mysterious invisible defense around Sevastopol.
It leverages two effects; firstly the navigation errors in the reported position of civilian vessels in Sevastopol. And secondly, the effect on radar satellite imagery. Open source intelligence analyst Damien Symons has noted these effects in the past month. Both indicate that there is a powerful jammer located in Sevastopol.
Sevastopol has several layers of defense aimed at stopping Ukrainian missiles and drone attacks on the important city. Sea drones have broken into the harbor on several occasions and aerial drones have targeted it since last year. On September 13th Ukraine launched Storm Shadow/SCALP missiles against the dry docks there. This effectively wrote off a landing ship and Kilo class submarine. This was followed up with more strikes including one on September 22nd which destroyed much of the Naval headquarters. These missiles had to fly through the infamous S-400 missile umbrella as well as local air defenses. They also had to operate despite Russia’s powerful electromagnetic defenses. The drones in particular are, generally speaking, susceptible to GPS jamming.
GPS Jamming Unmasked By Ship Positions
Since early November a number of ships and boats, which are in Sevastopol harbor, have been transmitting their location as Sevastopol International Airport. This is about 8 km (5 miles) north of their true location. The vessels are transmitting their position via AIS (automated identification system).It is possible for vessels to report their position incorrectly on purpose, or due to a myriad of technical issues. But this is systematic suggesting something else is at play.
So many vessels misreporting their location, and the false positions having such a concentration, points towards GPS interference. Jamming global positioning system signals, such as the American GPS, Russian GLONASS, or European Galileo (all referred to here generically as ‘GPS’), can affect AIS. The AIS transmission includes the coordinates of the vessel which in many cases this is fed directly from the GPS system. Without further analysis it is unclear whether the jamming is affecting all types of GPS or just one.
It is interesting that the vessels’ false positions are clustered around the international airport. This may indicate that the source of the jamming is there.
Russia is known to use GPS jamming to protect key sites. It has been used to protect President Putin’s stays at the luxurious Residence at Cape Idokopas, popularly known as “Putin’s Palace”. Since Ukrainian drones began striking Moscow GPS jamming was deployed there too. And ships were outfitted with powerful EW suites to protect the Navy Day Parade in St. Petersburg.
Jamming Of Radar Satellites
Jamming is also visible with the European Space Agency’s Sentinel 1 SAR (synthetic aperture radar) satellite. There was interference in imagery taken at 6:49am local time on November 23rd. It was even more marked at 6:36pm the next day, effectively obstructing the whole city. It is not possible to make out the ships in the harbor in the way it normally is.
Satim, a company which specializes in analyzing radar imagery, confirmed that SAR satellites operating at different frequencies did not appear to be affected. Sentinel 1 is a C-band radar while others are X-band. It is possible that the jamming was active when the Sentinel 1 satellite passed but not when the others did. Another straightforward interpretation is that the jamming is targeting C-band rather than X-band radars.
In both the AIS issues and the radar satellite interference, these may not be the primary target. The AIS errors can be seen as merely a side effect of the GPS jamming. Disruption to the satellites however does have some military value. Ukraine no doubt uses then as one of many means to observe Russian port activity and plan strikes. But again there may be other C band radars Russia is targeting, and the satellite interference may be secondary.
