Electronic warfare against GPS. Problems of foreign guided weapons
Ukrainian M142 MLRS fires. Photo of the Ministry of Defense of Ukraine
Foreign patrons supply the Kyiv regime with a variety of high-precision weapons equipped with guidance systems based on satellite navigation. This method of guidance raised understandable doubts, and now they have been confirmed. Attempts to use weapons with GPS receivers are met with opposition from Russian electronic warfare systems, as a result of which the effectiveness of advertised foreign models drops sharply.
Widely used technologies
The GPS global navigation system based on satellite constellation was put into operation in the early nineties. This system had obvious potential, and the Pentagon decided to equip all new types of weapons and equipment with satellite signal receivers. As a result, all modern US- or NATO-developed precision weapons use GPS as a primary or secondary guidance tool.
Since 2022, the United States and its partners have been actively supplying such weapons to the Kyiv regime. Ukrainian formations were helped to collect a fairly wide range of ammunition of different classes and types, which, as expected, should have influenced the course of hostilities. In addition, foreign partners and patrons of Kyiv had the opportunity to test their weapon in a full-scale conflict against a technically advanced army.
In the spring of 2022, it became known that several foreign countries were going to transfer controlled territories to Ukraine artillery M982 Excalibur 155mm projectiles. Deliveries of these products began a few weeks after the first reports. The M982 projectile is equipped with satellite and inertial navigation devices, which, according to the manufacturer, provide a CEP of no more than 4-5 m.
Unexploded Excalibur shell, October 2023. Photo Telegram / BMPD
Soon, in the summer of 2022, the first M142 HIMARS launchers were sent to Ukraine. Subsequently, their fleet was replenished, and standardized M270 MLRS products were also transferred. Along with these combat vehicles, adjustable missiles of the GMLRS family were supplied. They have a flight range of about 90 km and are equipped with a GPS-based guidance system, which should provide a CEP of no more than 8-10 m at any launch distance.
In the spring of 2023, the Kyiv regime received the first batch of controlled aviation JDAM series bombs. These products are built on the basis of free-falling ammunition and are equipped with a special control module. The latter includes a satellite signal receiver and an autopilot that controls the flight. At the beginning of 2024, it became known about the delivery of similar French-made AASM bombs. Somewhat similar to the JDAM is the GLSDB ammunition designed to be launched from the M142 and M270. It also relies on satellite navigation and is guided according to pre-entered coordinates.
Since 2022, foreign states have supplied Ukraine with numerous unmanned aerial vehicles of various classes and types. Some of them were guided munitions and used GPS to guide them to the target. Other UAVs use satellite signals to navigate and fly.
Predictable problems
The disadvantage of GPS and similar systems from the very beginning was considered to be low resistance to electronic countermeasures. A relatively weak signal from a satellite can be suppressed by interference or replaced with a false one. Negative expectations and forecasts of this kind were confirmed during the fighting.
A JDAM bomb under the wing of a Ukrainian MiG-29. Photo The Warzone
Since the first weeks or months of the Special Operation, Russian units have been using “anti-drone guns” of various models. Specialized portable jamming stations suppress GPS signals, and small UAVs lose the ability to navigate and further fly. Stationary stations with similar functions, capable of simultaneously covering an entire area, have also become widespread.
As early as 2022, reports began to emerge of successful use of other means EW against the guided weapons of Ukrainian formations. At first, the enemy and its patrons did not admit this, but by the end of last year the situation had changed. Foreign military personnel and the press began to raise the issue of Russian counteraction and the reduction in the effectiveness of high-precision weapons.
The first messages from abroad last year contained the most general formulations. It was argued that Russian electronic warfare does not allow the effective use of GMLRS, GLSDB, Excalibur, etc. projectiles. Problems arise with aircraft weapons and UAVs.
In mid-March, more precise information was presented at hearings in the US House of Representatives. One of the invited specialists pointed out that at the beginning of combat use in Ukraine, Excalibur shells showed an effectiveness of approx. 70%. When the Russian army began using electronic warfare against them, the effectiveness dropped to 6%.
A fragment of a downed GLSDB ammunition, February 2024. Photo Telegram / "Warrior 2nd Rank"
A few days ago, Bill LaPlante, the US Deputy Secretary of Defense for Acquisition and Supply, spoke at an open event. He said that another American-developed model had encountered the problem of interference “and other factors,” and as a result, its effectiveness was low. The deputy minister did not name the model, but from some of his words, it is clear that this is the latest Rocket GLSDB.
Counter-counteraction
In real combat conditions against a technically advanced enemy, even advanced and advertised foreign-made models did not perform well. In this regard, the United States began processes of further improvement of weapons aimed at countering electronic warfare and achieving high efficiency in combat use.
The first measure of this kind is to expand the functions of JDAM aerial bombs. On May 3, the US Air Force issued Scientific Applications and Research Associates Inc. (SARA) contract for the supply of passive radar subsystems HOJ (Homing-om GPS). The number of products ordered has not been announced, but their total cost exceeds $23,5 million.
SARA's HOJ subsystems are planned to be integrated into the JDAM suite. With their help, an air bomb will be able to find radio signal sources and aim at them. Such functions are primarily planned to be used to search and destroy electronic warfare stations.
HOJ subsystem. Photo by SARA
An official message from the Pentagon notes that HOJ devices, along with JDAM kits, could end up in Ukraine. In this case, Russian jamming stations are considered as targets for them. At the same time, as practice has shown, the United States itself needs such subsystems. It is unclear how serial products of the latest order will be distributed.
It is likely that ordering HOJ products will not be the only measure aimed at increasing noise immunity and maintaining the effectiveness of weapons. Perhaps the Pentagon will order other devices with similar functions and implement them in the design of other ammunition. It should also be expected that recent experience will be immediately taken into account in new weapons projects.
Proven by practice
At one time, a massive transition to satellite navigation in all major areas looked like a logical and promising step. The GPS system has made it possible to significantly increase the accuracy of coordinate determination and guidance. Distinguished by its convenience and simplicity, it was able to displace other methods of navigation and seriously influenced the development of guided weapons.
However, satellite navigation is not without its disadvantages, and it is now showing what they can lead to. It is obvious that the experience of current military operations will be taken into account by all leading countries and will seriously influence the development of guided weapons. Whether they will abandon systems like GPS or begin to look for ways to improve them, time will tell.
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