The drones began crashing on Ukraine’s front lines, with little explanation. For months, the aerial vehicles supplied by Quantum Systems, a German technology firm, had worked smoothly for Ukraine’s military, swooping through the air to spot enemy tanks and troops in the country’s war against Russia. Then late last year, the machines abruptly started falling from the sky as they returned from missions.
“It was this mystery,” said Sven Kruck, a Quantum executive who received a stern letter from Ukraine’s Ministry of Defense demanding a fix.
Quantum’s engineers soon homed in on the issue: Russians were jamming the wireless signals that connected the drones to the satellites they relied on for navigation, leading the machines to lose their way and plummet to earth. To adjust, Quantum developed artificial intelligence-powered software to act as a kind of secondary pilot and added a manual option so the drones could be landed with an Xbox controller. The company also built a service center to monitor Russia’s electronic attacks.
“All we could do is get information from the operators, try to find out what wasn’t working, test and try again,” Mr. Kruck said.
A battle is raging in Ukraine in the invisible realm of electromagnetic waves, with radio signals being used to overwhelm communication links to drones and troops, locate targets and trick guided weapons. Known as electronic warfare, the tactics have turned into a cat-and-mouse game between Russia and Ukraine, quietly driving momentum swings in the 21-month old conflict and forcing engineers to adapt.
Electronic warfare has been a feature of wars for more than 100 years. During World War II, the British mimicked German radio signals to deceive targeting systems that bombers used, which Winston Churchill popularized as the “battle of the beams.” In the Cold War, the Soviet Union invested heavily in electronic weapons to gain an asymmetric advantage against the missiles and planes from the United States.
In recent decades, the use of electronic attack and defense has been more lopsided. In the Iraq war in the 2000s, the United States used gadgets called jammers to create so much radio noise that improvised explosive devices could not communicate with their remote detonators. More recently, Israel has jumbled GPS signals in its airspace with electronic warfare systems to confuse would-be attacks from drones or missiles.
The war in Ukraine is the first recent conflict between two large and relatively advanced armies to widely deploy electronic warfare abilities and evolve the techniques in real time. Once the purview of trained experts, the technologies have spread to frontline infantry troops. Ukrainian drone pilots said they constantly fine-tuned their methods to parry the invisible attacks. One day, a new radio frequency might work, some said. The next, a different antenna.
The tactics have become so critical that electronic warfare received its own section in a recent essay by Gen. Valery Zaluzhny, Ukraine’s top military commander. “Widespread use of information technology in military affairs” would be key to breaking what has become a stalemate in the conflict with Russia, he wrote.
The techniques have turned the war into a proxy laboratory that the United States, Europe and China have followed closely for what may sway a future conflict, experts said.
Gen. Charles Q. Brown Jr., the chairman of the Joint Chiefs of Staff, raised the topic of electronic warfare this year in prepared remarks for a Congressional hearing. NATO countries have expanded programs to buy and develop electronic weapons, said Thomas Withington, an electronic warfare expert at the Royal United Services Institute, a British security think tank.
“The war in Ukraine has been the performance enhancing drug for NATO’s electromagnetic thinking,” he said. “It has been the thing that concentrates minds.”
Antennas and jammers
As Russian tanks rolled toward Kyiv in February 2022, the Russian military initially made good on its reputation as one of the world’s best at electronic warfare. It used powerful jammers and decoy missiles to inundate Ukrainian air defenses, leaving Ukraine reliant on aircraft to fight off Russian planes.
The electronic weapons do not appear dangerous at first glance. They are typically satellite dishes or antennas that can be mounted on trucks or set up in fields or on buildings. But they then beam out electromagnetic waves to track, trick and block sensors and communication links that guide precision weapons and allow for radio communications. Just about every communications technology relies on electromagnetic signals, be it soldiers with radios, drones connecting to pilots or missiles linked to satellites.
One basic but effective tool is a jammer, which disrupts communications by sending out powerful signals at the same frequencies used by walkie-talkies or drones to cause so much disturbance that beaming a signal is impossible. Jamming is akin to blasting heavy metal in the middle of a college lecture.
Another key weapon sends a signal that pretends to be something it is not, like a satellite link. Called spoofing, the fake signal can convince a drone or missile it is miles off course by feeding it false coordinates. In other cases, spoofers ape the signals made by missiles or planes to trick air defense systems into detecting attacks that aren’t happening.
Other tools listen for beams of radiation and seek to locate their origin. These devices are often used to find and attack drone pilots.
After early success using these tools, the Russian military stumbled, analysts said. But as the war has stretched on, Russia has innovated by making smaller, mobile electronic weapons, like anti-drone guns and tiny jammers that form a radio-wave bubble around trenches.
“The Russians have been more nimble at responding than we would have expected from their ground behavior,” said James A. Lewis, a former U.S. official who writes on technology and security for the Center for Strategic and International Studies in Washington. “That should be worrisome for NATO.”
