In recent years, with the maturation and development of drone swarm technology, drone “swarm” warfare has gradually moved from theoretical concepts to battlefield practice. Since May 2019, the Houthi armed forces have repeatedly used drones to carry out small group strikes on oil and gas facilities within Saudi Arabia, causing significant losses to the Saudi side. The power of drone “swarm” warfare is becoming apparent, and strengthening research on the key difficulties of anti-drone “swarm” warfare and actively seeking countermeasures is of great significance for maintaining air defense security in future combat.
Challenges of Anti-Drone “Swarm” Warfare
As the concept and technology of “swarm” warfare continue to evolve, drone “swarm” warfare is progressing at an astonishing speed, and existing combat forces and means face many challenges in anti-drone “swarm” warfare.
Stealth performance makes detection difficult. The types of drones in a swarm are usually small or micro drones, which are small in size, have weak electromagnetic signals, and low flight noise, making them difficult to detect with radar and acoustic, optical, or infrared detectors. Moreover, the platforms that deploy drone swarms are diverse and flexible; they can either take off directly from their origin and form a formation to the target; or they can take off from different locations and approach the target along different paths; or they can be transported by large aircraft or ships, releasing them to form a “swarm” when close to the battlefield, making early reconnaissance and detection quite challenging.
Modular design complicates function identification. The lightweight and micro drones in a swarm usually adopt a modular design, allowing different kits to be mounted according to the mission. For example, they can carry sensors, laser target designators, and electronic jammers to perform various tasks such as battlefield surveillance, target designation, and electronic warfare; or they can be equipped with reconnaissance devices or various warheads to be converted into reconnaissance drones or attack drones. When various types of drones densely appear in the air, even if detected, it is difficult for ground air defense systems to accurately identify the nature of the targets based on their appearance since the drones do not emit electromagnetic waves, which affects the allocation of anti-drone forces and strike order decisions, potentially missing combat opportunities.
Short warning time complicates fire interception. Unlike the high-mobility serial combat methods in traditional mechanized and informationized warfare, the most significant feature of drone “swarm” warfare is the use of low-cost, high-quantity, and wide-area cluster coverage in parallel combat, launching sudden actions that rapidly saturate and paralyze the enemy’s defense system’s detection, tracking, and interception capabilities. Data shows that when a drone “swarm” attacks at a speed of 250 kilometers per hour, the defense system has only 15 seconds from detecting the target to initiating interception, resulting in a short warning time that complicates reasonable fire allocation, allowing some drones to evade interception and attack enemy targets.
Constructing an Anti-Drone “Swarm” Warfare System
To address the characteristics of drone “swarm” warfare, a comprehensive application of reconnaissance, jamming, striking, and interception methods is necessary to build an anti-drone “swarm” warfare system that enhances the system’s resistance capabilities through multiple measures.
Three-dimensional networking for multi-level detection and warning. Early awareness of the attack threat from drone swarms is a prerequisite for organizing and implementing anti-drone “swarm” warfare. For instance, implementing vertical multi-level detection by deploying long-range, medium-range, and short-range radars layered in the direction of the drone swarm’s approach, responsible for detecting the swarm’s mother ship, monitoring drones entering the defense zone, and identifying and tracking “low, slow, and small” targets; implementing planar networking detection by connecting ground radars of different systems, frequency bands, and working modes through networked communication links to form a radar network for unified management, allocation, and cooperative detection, achieving wide-area coverage, seamless monitoring, and multi-point observation of drone “swarm” targets; and implementing vertical three-dimensional detection by networking early warning aircraft, long-endurance drones, and tethered aerostats to leverage the advantages of early warning aircraft’s wide detection range, long-endurance drones’ continuity capabilities, and tethered aerostats’ long hovering time for top-down blind-spot-free detection of drone swarms.
Combined defense and multi-channel interference suppression. In the initial stage of anti-drone “swarm” warfare, various means such as electronic countermeasures can be used to interfere with and suppress the operational effectiveness of drone swarms. For example, by launching specific energy light waves for active interference against the drone swarm, or using passive interference methods such as camouflage and fake disguises on friendly targets to reduce the reconnaissance effectiveness of optical sensors; interfering with the drone swarm’s radar systems by emitting high-power electromagnetic jamming signals to suppress or cover the lightweight synthetic aperture radar carried by drones, reducing their detection effectiveness.
Focusing on swift strikes with multi-method firepower. In the mid-stage of anti-drone “swarm” warfare, the comprehensive use of anti-drone air defense weapon systems can achieve hard kills against incoming drone swarms. Based on understanding the operational formation and flight arrangement of the incoming drone swarm, targeted selection of laser or microwave weapons, or a combination of both, can maximize the effectiveness of the laser weapons’ “point kill” and the microwave weapons’ “area destruction” functions. Additionally, anti-drone capabilities can be added to anti-aircraft artillery, air defense missile systems, and combined air defense systems, utilizing warhead shrapnel or kinetic energy to achieve hard kills against drone swarms, with attack methods including long-range ambush of the mother ship, ground fire strikes, and aerial fire strikes. Although this method is relatively traditional, its advantages include high technological maturity and reliable strike effectiveness.
Swarm destruction with multi-method interception. After the drone “swarm” has been interfered with and subjected to fire strikes, there may still be sporadic drones continuing to approach the target area. At this point, close-range deployment of combat-style drone “swarms” can create an aerial fire interception net to completely annihilate the remaining operational forces. Upon detecting enemy drone “swarms,” timely launch of friendly drones can use “swarm” against “swarm” to disrupt the formation of the incoming drone “swarm,” causing mid-air collisions. Large “net” type interceptors can also be launched from the air and ground to create an interception net made of conductive carbon fiber in the air, enveloping the target drones and causing their communication systems, power systems, or control systems to fail, ultimately capturing enemy drone swarms.