Chinese gangsters appear to have joined the Russian military in developing and using technology for spoofing (misdirecting) GPS signals. The use of this tech has been experienced around the city of Shanghai since 2018. The Chinese GPS spoofing was implemented differently from the Russian method. Whereas 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 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 (Automatic Identification System) transponders. By international law, all large seagoing ships were required to carry and use AIS equipment, which constantly broadcast 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 as were GPS devices ashore that were within the circle.

The Chinese government denied responsibility for this GPS spoofing and blame it on smugglers who apparently use the 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 sand illegally obtained nearby and being taken out of 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.

Whoever is using this new GPS jammer around Shanghai has not been caught yet, in part because the device has apparently only been used six times and then only for short periods. From the evidence collected so far, it seems that if the jammer was kept on long enough the extent and center of the crop circle could be located and police sent to that location to seize the equipment and those using it.

This is not the first time criminals have obtained and used electronic signal jamming equipment. The gangster gear is usually for some types of communications systems of radar. Jamming GPS is something new, especially in ways never seen before. But now seagoing smugglers are employing more electronic jamming equipment as they seek to evade detection and avoid capture once detected. Police determined that the spoofing signals seemed to be somewhere in a building owned by a local petrochemical company. A search of the premises and questioning of people who worked there did not reveal anything. Then again the gangsters may have been in the building illegally and left as soon as they were done using the spoofing equipment.

A GPS spoofing/jamming system requires some skilled people to design and build. Chinese gangsters have carried out the development and construction of sophisticated equipment before but so far police have no leads to who it might be. There are suspicions that the equipment could be North Korean, as North Korea has developed more complex methods to smuggle sanctioned goods in and out of North Korea. If they had created equipment like this they certainly would not issue a press release about it but would sell it for the right price, in cash or cryptocurrency.

Users of GPA jamming gear tend to keep quiet about it. For the last few years, there has been growing evidence that Russia has been frequently jamming or spoofing GPS signals, mainly to hide the exact location of key people or military units. Developing equipment like this is easily within Russian capabilities. In early 2019 a civilian think-tank (C4ADS) released a report in which they described how they had found nearly 10,000 instances that 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 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. The spoofing replaced the actual satellite signal with a false one that rendered smart bombs or planned attacks on targets inaccurate.

Spoofing 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 (Internal Navigation System) 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 information on spoofing incidents. To further complicate the issue there have also been instances where AIS equipment would report it was getting no GPS signal at all. Large ships usually carry two AIS units, in case one malfunctions. But when the Shanghai jammer was used the AIS would sometimes receive no signal at all, which caused an alarm to go off.

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 (Electronic Warfare) equipment that might be useful to them.

What was curious about this incident was that it had no impact on the NATO military exercises and even commercial airliners operating in the area had backup (INS) systems 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. C4ADS concluded that the Russian spoofing incidents were possibly common practice whenever president Putin traveled, probably as a security measure to render assassination attempts using UAVs armed with explosives. This has become a common tactic with Islamic terrorists, who consider Putin a prime target for UAV attacks.

NATO nations have long been aware of the Russian EW activities, especially the growing number of Russian jamming and spoofing systems. Some of these were demonstrated in Syria and Ukraine, where Russia considers complaints about the disruption caused by their jamming or spoofing as free advertising for this equipment. Russian GPS jammers have some military use but also have appeal for non-military customers. For example, in 2016 Russia began marketing a new, portable GPS jamming system called Pole 21. This system was special because individual Pole 21 units can be mounted on existing cell phone towers (or alone on portable towers). Each Pole 21 unit can put out 20 watts and jam signals from GPS (as well as the similar GLONASS, Galileo and Beidou systems) out to 80 kilometers. Pole 21 is also designed to act as a backup GSM transmitter of commands for nearby Pole 21 units. In this way, the Russians say a wide area can quickly be protected from GPS guided missiles and bombs as well as shutting down vehicle GPS systems. The Russians admit that Pole 21 would also cripple all commercial GPS devices in the jammed areas. The biggest problem with Pole 21 is that Russia has been developing and selling many different GPS jamming systems since the mid- 1990s and they have proved to be ineffective in combat. Russian firms keep producing these types of jammers because there is a market for them.

This Russian interest in GPS jamming first became public in the early 1990s when a private Russian firm, AviaConversia, was founded for the purpose of developing cheap, lightweight and reliable GPS jammers. By 1997 the firm was offering commercial and military customers four different models of GPS jammers (for about $4,000 each). This gear only put out 4-8 watts, making them very tough to find and bomb. These jammers were advertised as able to effectively block GPS signals out to 150-200 kilometers, depending on terrain. These jammers could run off batteries and weighed between 8 kg (18 pounds) to 12 kg (26 pounds) without batteries. When operating, the jammers consumed less than 25 watts of power.

By the mid-1990s plans for building your own GPS jammers were appearing on the Internet using commercially available parts costing less than a hundred dollars. Soldering skills were required. Soon similar assembled units were available on the Internet for as low as $40. At the same time, American GPS experts pointed out that these jammers had insufficient power to jam GPS for most military GPS receivers but would probably interfere with a lot of commercial stuff, especially consumer products. The U.S. Air Force later revealed that this was the case. This was demonstrated in 2003 when Iraq tried unsuccessfully to use AviaConversia type jammers against American GPS guided bombs.

By 2002 AviaConversia had disappeared, apparently absorbed in new, classified, Russian military jamming efforts. In the 1990s AviaConversia had made much of its connections with the Russian armed forces and the implied assurance that its jammers worked. After 2001 U.S. Department of Defense experiments found that the cheap jammers were not that effective, and larger ones, built from off the shelf components, and costing nearly $10,000, were also largely ineffective against military-grade GPS guidance systems. At the same time, the Department of Defense has been building and testing GPS jammer detectors, as well as homing systems sensitive enough to guide a missile to any active jammers.

By 2010 the U.S. Department of Defense was spending a lot of money on developing a jam-resistant replacement, or backup (depending on who you talk to), for GPS. The best candidate was an improved INS, which has existed for nearly a century but since the 1960s had gotten smaller, cheaper, and more reliable as electronic components did the same. Basically, INS uses three gyroscopes and three accelerometers to constantly measure changes in direction and changes in velocity. With that, the INS will always know where it is in relation to its initial starting point (which can be obtained initially via unjammed GPS or older means). Miniature INS devices have long served as a backup for GPS guided weapons. But while GPS guidance can land a bomb or missile within 10 meters (32 feet) of a target, INS can only achieve 30 meter accuracy. GPS also has the advantage of not needing to have its exact position entered after the INS is turned on. On the upside, that means INS cannot be jammed or spoofed. These micro- gyroscopes and accelerometers have become standard in many smartphones to not only detect orientation but also movement. The use of this tech by smartphone makers resulted in even cheaper and more reliable designs that proved very useful for military INS backups for GPS.

After 2010 American researchers created new concepts and technology that could greatly improve current INS accuracy and cost. By 2013 prototypes proved they could be nearly as accurate as GPS and almost as small. Cost was still a factor, with the new INS still costing more than 10 times what GPS does. But this is all a big improvement over what has been available before. The new INS can now be used to monitor GPS and alert the operator that their GPS has either developed a problem or is being jammed. The new INS is also useful for some fast missiles that often lose their GPS signal as they maneuver. Another urgent chore for INS is to alert users that their GPS is being spoofed (sent a false signal that is luring the user away). Thus, even with the ability of 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 consumers GPS is reliable enough to keep the INS gear out of the consumer market. But the demand from the airlines, shipping companies and the military is huge. However the tech remains popular for smartphones and other consumer items, but not as INS. That is changing as some smartphone (and smartwatch) manufacturers seek to use INS to automatically fill in if the user temporarily loses the GPS signal.

Many Department of Defense navigation and electronics experts believe current anti-jamming efforts are sufficient to keep military GPS use viable, but the new INS technology has attracted a lot of attention in the military as backups are always appreciated because when equipment fails in combat 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.

While American troops have not yet encountered much (if any) battlefield GPS jamming, the threat exists. Currently, American troops can experience this sort of thing in Ukraine (where NATO nations have military advisors and observers) and Syria. This jamming tech is also showing up in Iraq and Afghanistan. Before that, the most tangible evidence of this came from North Korea, which has long made, sold, and itself used GPS jammers. In 2012 North Korea attacked South Korea with a massive GPS jamming campaign. The jamming began in late April and continued for over two weeks. It took less than a day to confirm that the signal was coming from North Korea and was mainly aimed at the South Korean capital (Seoul). The jamming had little impact inside the city itself (the ground-based jamming signal was blocked by buildings and hills) and was only noted by several hundred aircraft landing or taking off from local airports and over a hundred ships operating off the coast. In all these cases the ships and aircraft had backup navigation systems, which were switched on when GPS became unreliable. This is how navigation systems, especially those that rely on an external (satellite) signal, are designed.

The 2012 incident was the third time North Korea has used GPS jamming against South Korea. For most of March 2011, North Korea directed a GPS jamming signal across the border towards Seoul. A separate jammer has been directed at cell phone traffic. The GPS jamming signal could be detected up to a hundred kilometers south of the DMZ.

The usual response to GPS jamming is to bomb the jammers, which are easy to find (jamming is nothing more than broadcasting a more powerful version of the frequency you want to interfere with). But such a response could lead to more fighting in Korea, so the south protested and refrained from responding with force. The jamming was a nuisance more than a threat and most military equipment is equipped with electronics and other enhancements to defeat it. The North Korean jamming confirmed what was already suspected. So now South Korean and American electronic warfare experts have an opportunity to study the effects of jamming on a large metropolitan area. It caused intermittent problems for users of GPS devices and many more cell phone connectivity problems. There were briefer and less powerful jamming incidents in August and December of 2010.

Meanwhile, this is old news for the U.S. Department of Defense, which has been developing anti-GPS jamming technology since the late 1990s. For years military aircraft have been equipped with complex and expensive GPS receivers that will usually continue to work even if they are being jammed. There are several ways you can defeat attempts to jam GPS signals. While some of the methods are well known, others are classified. No one has successfully used GPS jammers in combat yet but the potential is there. Now the North Koreans are giving large-scale demonstration of GPS jamming. Anti-jamming technology is increasingly complex. None of the major players (the U.S., Russia, China, Israel, and several other industrialized countries) are talking, and for good reason. If you don't know what techniques the other guys are using you can't deal with them.

China and Russia are both selling GPS jammers. In 2007, China brought to market a powerful truck-mounted GPS jamming system. These "GPS jamming vans" are meant to create a protective "bubble" over an area the van is in the middle of. A year before the 2003 invasion of Iraq it was believed that Saddam had bought many GPS jammers to deal with U.S. JDAM GPS smart bombs. The JDAM has a backup INS, which was no secret, and the Iraqi GPS jamming efforts had no significant effect on the 2003 campaign.

There are several approaches to defeating GPS jamming, and knowing which one each American GPS guided weapon uses makes it easy to develop a way to jam the "jam-proof" GPS. The U.S. Air Force is understandably reluctant to discuss what they are doing. Given the cost of jam proofing all existing GPS weapons, it's more likely that jam-proof GPS weapons will only be used against targets where the GPS accuracy is vital. Against most targets, the accuracy provided by the inertial guidance system will do. Also, note that you can bomb GPS jammers with a bomb equipped with a guidance system that homes in on a GPS jamming signal. For that reason, it's thought that any use of GPS jammers will involve dozens of jammers in each area so protected. The GPS jamming has no effect on the even more accurate laser-guided bombs, and some countries buy smart bombs with both laser and GPS/INS systems. Most countries are working on anti-jamming tech in anticipation of encountering more jamming if war comes.