November 14, 2023: The fighting going on in Ukraine and, to a lesser extent in Syria involves a lot of efforts to jam GPS navigation signals and degrade the accuracy of weapons using GPS navigation. In theory, jamming GPS navigation is relatively straightforward. The jammers disrupt the signal GPS navigation systems receive from space satellites that provide worldwide signals to GPS receivers in the air, at sea or on the ground. If someone jams the GPS signal, most GPS-based guidance systems will switch to an INS (inertial Navigation System) back up.

In the last few decades new technologies have greatly improved INS accuracy and lowered costs. In the last decade, new INS tech resulted in INS that was nearly as accurate as GPS and almost as compact. The new INS tech was more expensive, but as more of it was sold, the cost will come down. Cost was initially a factor because the new INS units with the new tech cost more than 10 times GPS. Despite that, there were markets for the more expensive INS. The new INS devices can be used to more effectively monitor GPS and alert the user that their GPS has either developed a problem or is being jammed. INS cannot be jammed because it is self-contained and does not rely on any external signal. INS does receive constant position updates from the GPS unit it works with. That keeps the INS as accurate as possible. But if those updates suddenly stop or become erratic, INS systems are programmed to stop using GPS signals and switch to INS only mode.

This feature is often essential in some weapons. For example, some very fast or highly maneuverable missiles sometimes briefly lose their GPS signal as they maneuver. A more complex task is INS equipped to effectively deal with the growing use of GPS spoofing, or misdirecting. This involves Electronic Warfare (EW) equipment that can mislead rather than jam without alerting the victim that their navigation system might not be reliable. Thus, even with the ability of GPS anti-jamming tech to keep up with jammer technology, there is still a demand for a new INS. That has led to smaller, cheaper and more accurate INS systems. Aside from airlines and commercial shipping, there is not much of a mass market for these new INS systems because for most users, GPS is reliable enough to keep the INS gear out of the more cost-sensitive markets. But the demand from the airlines, shipping companies and the military is huge. INS tech is becoming a popular feature for high-end smartphones and other consumer items, because some smartphone and smartwatch manufacturers seek to use INS to automatically fill in if the user temporarily loses the GPS signal.

Several nations, particularly the U.S., Russia and Israel, develop electronic systems that disrupt satellite navigation systems like GPS or the Russian GLONASS. Both nations use their jamming and anti-jamming tech against each other because Russia maintains a naval base and airbase on the Syrian coast while Israel is constantly under attacks by Iranian UAVs and missiles launched from Syria. Israeli missiles regularly hit Iranian targets in Syria and Russia uses its GPS jamming systems to disrupt these attacks. Israel has responded with new tech installed in the missile guidance systems that reduces or eliminates the effectiveness of the jamming. This GPS jamming and counter-jamming competition has been going on for several decades and became particularly intense when Russian forces arrived in Syria in late 2015. Before that Russia had provided their ally Syria with these jamming weapons while Israel and the United States cooperated in developing new jamming tech. Now the new tech is showing up in Ukraine, where there is a lot of jamming, spoofing and general mayhem directed at new satellite navigation and INS tech.

Details of the new jamming technologies are usually kept secret but those that are sold as commercial products must reveal some technical details. For example, in 2021 the Israeli military announced that it was the prime backer of the new Advanced Navigation Technology Center. This new division of state-owned IAI (Israel Aerospace Industries) develops and manufactures new generations of INS technology to complement or replace satellite (GPS) guidance. IAI did not provide any more details of the new INS technology, not even the name of the new system. IAI already develops and makes INS systems as unjammable backups for GPS systems, but the future is seen as a better INS that is less reliant on GPS.

Many defense specialists on navigation and electronics experts believe current anti-jamming efforts are sufficient to keep military GPS use viable for a while, but the improvements in GPS jamming and spoofing technology have been arriving faster than expected. Despite the secrecy about GPS disruption, since 2017 there has been growing evidence that Russia has been frequently jamming or spoofing GPS signals, mainly to hide the exact location equipment that allows GPS tracking. Those techniques continued to show up in Ukraine.

Developing equipment like this is easily within Russian capabilities. In early 2019 a report made the news revealing that there had recently been nearly 10,000 instances where someone, apparently Russia, had been jamming or spoofing satellite navigation signals. Not just the American GPS, but also signals from non-American satellite navigation systems (Chinese Beidou, EU’s Galileo, Japan’s QZAA and even the Russian GLONASS). Much of this activity was not outright jamming but harder to detect spoofing. This was apparently done to conceal the true location of key Russian officials, like President Putin, and Russian military units. The spoofing was particularly common for Russian military forces in Ukraine and Syria. Spoofing replaced the actual satellite signal with a false one that rendered smart bombs or planned attacks on targets inaccurate. Spoofing can introduce false signals gradually and sometimes delay a navigation system's realization that it is being deceived. That’s one function of INS, to act as a monitor for GPS as well as a backup.

Current INS tech relies on receiving an accurate GPS location initially and periodically thereafter to keep both GPS and INS location data in sync. GPS depends on continuous satellite signals to operate, and the INS is used to step in and replace GPS when the satellite signal becomes temporarily too weak, or absent. When an accurate GPS signal is achieved, INS goes back into standby mode. Spoofing can now mimic these momentary disruptions and evade detection as a false signal by the INS, which is completely self-contained. This is sometimes a problem for American guided weapons sent to Ukraine that do not have the latest jamming detection and countermeasures tech installed.

Israeli INS researchers are not the only ones seeking an INS that is accurate and persistent enough to replace GPS for extended periods. INS has long suffered from the inability to provide as accurate a location as satellite navigation systems while also suffering from “drift” as the gyroscope and acceleration capabilities now performed by microelectronics of the chip-based INS cannot maintain as continuously precise location as the space satellite-based system can. This is no longer seen as an insurmountable problem, nor is the large cost-difference between GPS and INS tech. Israel apparently feels it is closer to a solution than anyone else.

Meanwhile, spoofing satellite navigation systems has become more popular and practical because it does not require expensive or high-tech equipment. While American weapons and military navigation systems have a backup in the form of unjammable INS systems, these are useless if the spoofing is not detected. American systems are supposed to detect spoofing and revert to INS but the Americans do not disclose details of how these systems work in order to make it difficult for spoofing systems to be modified to be less detectable. That is one reason why the U.S. has not released detailed information on spoofing incidents because some of them may have evaded the INS spoofing detection tech.

To further complicate the issue there have also been instances where mandatory AIS (Automatic Identification System) transponders that all large ships must carry are more frequently reporting instances of getting no GPS signal at all. Large ships usually carry two AIS units, in case one malfunctions so AIS failure can be ruled out as a cause. But when something else is manipulating the GPS signal it becomes possible to deceive the unjammable INS. New INS systems can eliminate that risk by replacing GPS most of the time.

The new INS technology has attracted a lot of attention in the military as backups are always appreciated because when equipment fails in combat, or for commercial users like aircraft or ships, it’s literally a matter of life or death. Meanwhile, the U.S. is building and testing more compact GPS anti-jamming systems for smaller (as small as 200 kg/440 pounds) UAVs. This is part of a program to equip all American UAVs, even the smallest ones, with more secure GPS. While all UAVs can be “flown” by the operator, the GPS makes it a lot easier for the operator to keep track of exactly where his UAV is at all times, and sometimes the UAV is programmed to simply patrol between a series of GPS coordinates. If the GPS jams or fails, the operator can usually use the video feed to find landmarks on the ground and bring the UAV back to where it can be seen and landed. Other UAVs have a failsafe system for the GPS. When it is no longer available the UAV turns around and heads back in the general direction of the operator. When the operators detects the returning UAV it can send it a signal to determine if this is because of equipment failure or possible jamming. This is preferable to allowing the GPS-less UAV to keep flying until it runs out of fuel and crashes somewhere,

Most GPS reliability threats are coming from a few suppliers like Russia, China and North Korea. These nations have developed all manner of GPS jamming technology, and in 2019 it became public that the Russians were using GPS new spoofing technology to conceal the true location of senior leaders and some military units.

Developers and users of GPS jamming gear tend to keep quiet about what they do because this sort of thing is illegal in peacetime, especially when civilians experience GPS disruptions themselves. When the United States tests military GPS jamming it does so at sea or in remote areas and warns nearby civilians who might encounter GPS problems to be aware of the tests and act accordingly. This warning policy has been in use for decades because of the growing number of new electronic equipment designs that could cause problems for civilians if the disruptive effect extended farther than expected.

Other nations are not as secretive in complaining and often the culprit is Russia. In late 2018 Finland and Norway went public with their accusations that Russia deliberately jammed GPS signals in northern Finland and Norway from a location near the Russian military bases in the Kola Peninsula on the Barents Sea. The jamming took place as NATO held its largest training exercise since the Cold War ended in 1991. Russia denied any responsibility even though they are known to possess long-range jammers for GPS and other signals. Norway said they had tracked the jammer to a specific location but when Russia refused to admit any involvement Norway refused to explain how they tracked the signal because that would provide Russia with information on Norwegian EW equipment that might be useful to them.

In 2020 Iran was caught testing spoofing tech at a military facility in the capital Tehran and trying to keep it secret. It is not known if the Iranians developed the spoofing tech themselves or received it from Russia or China.

Until the appearance of the new spoofing tech, GPS jamming had little or no impact on the NATO military exercises and even commercial airliners operating in the area had INS backup in case GPS signals were not working properly. The potential victims were civilians with smaller aircraft or on the ground who depend on commercial navigation gear using GPS. Then again, that may have been the point because Russian firms have long been producing a wide variety of GPS jammers that are generally ineffective against military GPS users but would be useful for criminals, terrorists or anyone involved in irregular warfare, as Russia has been in Ukraine since 2014. As for the damage to diplomatic relations with Norway and Finland, these two nations need no reminders of what a bad neighbor Russia is and historically has been.

GPS spoofing equipment has also found a market among criminal gangs. This was first encountered during 2018 in Shanghai, China where local gangsters were found to be using technology for spoofing GPS signals. Shanghai was just the beginning because this spoofing tech was subsequently encountered in twenty other Chinese coastal cities where gangsters ran profitable smuggling operations. The Chinese GPS spoofing was implemented differently from the Russian method. The Russian spoofing would make all GPS devices in an area appear in the same position instead of the many different positions they actually were. In contrast, the Chinese spoofing, when active, would show individual ships each in a different location but always around the same central point that was apparently where the spoofing signals were broadcast. This produced what was called a “crop circle” pattern. This was first noted by crews of ships slowly entering the port of Shanghai. While doing so they would watch the location of other ships via their AIS transponders. International law requires all large seagoing ships to carry and use AIS equipment which constantly broadcasts the GPS position of the ship, but there were cases where ships suddenly saw the AIS positions of ships near them change. The bridge crew could see, often with/or without, the use of binoculars, where the other ships actually were while, at the same time, the AIS display was showing them somewhere else within a circular area. After a few minutes, AIS signals would accurately report location again. In situations like this, it was noted that no GPS receivers onboard were receiving a signal, nor were GPS devices ashore that were within the circle.

The Chinese government denied responsibility for this GPS spoofing and blamed it on smugglers who apparently used a spoofing device to avoid being caught by the police while a smuggler ship was carrying illegal cargo. In one case the smuggler was caught anyway, because of an accident caused by the spoofing, and the smuggler ship was found to be carrying an illegally obtained spoofing system while transporting sand from, the port for sale elsewhere. Sand mining had been banned in this region because this valuable commodity was in great demand elsewhere and exporting more of it was damaging the environment.

GPS spoofing declined during 2020 but China revealed no details about what happened. In the past China has given local hackers a choice between going to prison or quietly working for the Chinese government. Russia uses similar tactics as do many other governments. One thing that was noted about the “Shanghai Spoofer” was that the spoofing often took place around oil terminals where ships smuggling oil for Iran or to North Korea often operated. The governments of Iran and North Korea also noticed this and could have received useful information on how the Shanghai spoofing gear worked. That’s one of the conspiracy theories popular with many Iranians and South Koreans.

Since 2022, many new spoofing and anti-spoofing technologies have shown up in Ukraine. While this battlefield is invisible, its impact is not. This is especially true when normally reliable guided systems suddenly become unreliable.