China's Naval Response: The 'Sky Guardian' as a Strategic Missile Shield Against the US Surface-to-surface Missile System (LRASM). Beyond Radar: AI-Based Anti-Missile System Targets Stealth Missiles

Abstract

This article, based on military OSINT sources, examines the evolving landscape of modern naval warfare, specifically addressing the unprecedented challenge posed by advanced anti-ship missiles such as the US AGM-158C Long-Range Anti-Ship Missile (LRASM). The LRASM’s combination of ultra-low altitude flight, advanced stealth, and highly autonomous artificial intelligence makes traditional naval defense systems vulnerable due to limitations in early warning, missile inventory, and close coverage of weapon systems.

Drawing inspiration from land warfare experience with cluster munitions and terminally sensitive submunitions, Chinese scientists and military engineers propose a conceptual and innovative naval anti-missile system, hypothetically named “Sky Guardian,” as a potential countermeasure under development by the Chinese People’s Liberation Army Navy (PLAN). “Sky Guardian” would represent a paradigm shift from passive point defense to proactive area-based defense. Its key features include preemptive salvo deployment of munitions, airborne stationing capability for submunitions, and a revolutionary top-down terminal detection and attack system using multi-modal sensors (infrared, millimeter-wave radar, passive electronic detection).

This top-down approach bypasses the main stealth optimizations of incoming missiles and exploits their inherent vulnerabilities when observed from above. The article details the design of the directional fragmentation warhead for effective neutralization of high-speed targets. It also explores the seamless integration of "Sky Guardian" into existing naval defense layers to improve terminal defense, harden weak spots, and counter saturation attacks. Finally, the article discusses future prospects, including potential evolution to defensive drone swarms and expanded multi-domain capabilities, highlighting "Sky Guardian" as a key development to address the next generation of anti-ship missile threats in the maritime competition.

by Gabriele and Nicola Iuvinale

The AGM-158C LRASM, a long-range, stealthy, and AI-guided anti-ship missile, poses a significant threat to traditional naval defenses.

With the evolution of next-generation anti-ship missile threats, such as the U.S. AGM-158C LRASM, the People's Liberation Army Navy (PLAN) faces unprecedented challenges. The LRASM's combination of ultra-low-altitude flight, advanced stealth capabilities, and highly autonomous artificial intelligence makes traditional naval defense systems vulnerable. In response to this increasing complexity in the maritime battlespace, China is exploring and presumably developing innovative defense concepts, including a hypothetical anti-missile system dubbed "Sky Guardian."

The challenges posed by missiles like the LRASM are multifaceted: the limited long-range early warning capability of shipborne radars against sea-skimming targets drastically reduces reaction time; the limited missile load in Vertical Launch Systems (VLS) makes it difficult to counter large-scale saturation attacks; and short-range weapon systems have limited ranges and potential blind spots against multi-directional attacks.

To overcome these vulnerabilities, the PLAN is looking at radically new defensive paradigms, drawing inspiration even from land warfare concepts.

A modern Chinese naval vessel, potentially a target for advanced anti-ship missiles and a platform for "Sky Guardian"-type defenses.

Inspiration from Land Warfare: The "Many-to-One" Paradigm

The "one shot, multiple kills" concept from land warfare experience with cluster munitions and terminally sensitive submunitions is providing valuable insights. Weapons like multiple rocket launchers equipped with intelligent submunitions have demonstrated the ability to saturate vast areas and autonomously engage multiple targets simultaneously. This approach, which contrasts the inefficient "one missile for one target" logic, is well-suited to the nature of swarm attacks conducted by modern anti-ship missiles.

Multiple Launch Rocket Systems (MLRS) provide inspiration for the "Sky Guardian" concept, demonstrating the effectiveness of saturating an area with submunitions.

Terminally sensitive submunitions, equipped with advanced sensors such as millimeter-wave radar and infrared imaging, can identify and strike target weak points from above. This "aerial mine" or "fire-and-forget" capability not only reduces reliance on continuous guidance but also maximizes damage effectiveness against mobile targets. Applying these principles to naval defense is crucial: if anti-ship missiles attack in groups with high mobility, an area saturation defense rather than point-to-point interception becomes strategically superior.

The "Sky Guardian": A New Chinese Naval Defense Architecture

China's purported development of the "Sky Guardian" represents a paradigm shift in naval air defense, moving from a passive response to the active and pre-emptive interception of a threat. Its technical characteristics, inspired by land-based concepts but adapted to the maritime environment, focus on three key aspects:

1. Advanced Launch and Deployment Mode

The "Sky Guardian" would abandon the traditional model of reactively launching interceptor missiles only after target detection. Instead, based on intelligence and early warning data, Chinese ships could pre-deploy salvos of "Sky Guardian" munitions along probable missile attack routes. These munitions, optimized for compatibility with existing multi-barrel launchers (such as modified jammers or CIWS), would allow for the rapid establishment of a multi-layered defense network around naval units. This "pre-netting" tactic would be particularly effective against low-altitude stealth missiles like the LRASM, which rely on "silent penetration" as their strength, rather than the traditional detection-interception sequence.

2. Aerial Loitering Technology for Submunitions

After launch, "Sky Guardian" munitions would rapidly ascend to a predetermined altitude and then disperse terminally sensitive submunitions. These submunitions could utilize aerial loitering technologies, such as controllable parachutes or autonomous multi-rotor systems (tactical drones). This capability would allow the submunitions to hover in a designated area or fly autonomously for an extended period, forming a persistent "aerial sentinel" over the threat corridor. This extends the useful engagement time and enables proactive defense.

3. "Top-Down" Terminal Detection and Attack

The most revolutionary feature of the "Sky Guardian" would be its "top-down" terminal detection system. Each submunition would be equipped with a multimodal sensor suite, including:

• Downward-looking infrared (IIR) imaging systems: Utilizing the latest uncooled focal plane array technologies, these sensors would be able to detect the thermal signatures of sea-skimming missiles. Even stealth missiles, optimized to reduce frontal/side radar and infrared cross-sections, exhibit significant thermal signatures from engine exhaust gases and aerodynamic heating when viewed from above.

  

• Millimeter-wave (MMW) radar: Capable of penetrating light fog and clouds, these radars can generate sufficient echoes even from the top surface of stealth missiles, as most stealth designs do not optimize radar scattering from above.

  

• Passive electronic detection systems (ESM): To detect any radar or communication emissions from incoming missiles, providing an additional layer of target confirmation.

Data fusion from these sensors, processed by advanced target recognition algorithms, would drastically reduce false alarms and increase the probability of detecting low-observable missiles. The top-down detection mode offers critical advantages: it bypasses the primary stealth optimization areas of anti-ship missiles and intelligently avoids multipathing and sea clutter issues that plague traditional radars. Furthermore, it fully exposes the missile's engine exhaust system, its primary infrared heat source, which is usually shielded only for rear and side observations.

A top-down view of a missile, highlighting the vulnerability that the "Sky Guardian" system aims to exploit.

Once a target is detected and confirmed, the "Sky Guardian's" integrated decision-making system would activate a directional fragmentation warhead. This warhead would release a cloud of high-velocity metallic fragments (up to 1,800 meters per second) along the missile's predicted flight path, creating a lethal "destruction cone." Such a "top-down" attack would strike the inherently more vulnerable upper surface of airborne missiles, causing catastrophic damage to vital internal components (guidance, avionics, propulsion) and compromising their structural integrity due to aerodynamic stress. The warhead design could include a "dual-layer fragment" design (penetrating and extended-fragmentation) and an "intelligent fuzing system" to optimize damage effectiveness.

Integration and Strategic Role in Chinese Naval Defense

The "Sky Guardian" is not intended to replace the PLAN's layered air defense systems but to complement them as an extension of terminal defense. It could play crucial roles:

• Terminal Enhancement: Acting as a last line of defense for missiles that evade long- and medium-range interceptions.

• Weakness Reinforcement: Being deployed in areas with limited radar coverage or firepower from traditional systems.

• Saturation Countermeasure: Forming a regional defense network to alleviate pressure on other systems during large-scale swarm attacks.

This innovative concept would be particularly well-suited for high-intensity naval combat scenarios, where the PLAN must face multi-directional saturation attacks. In coastal environments, where electronic interference and complex terrain reduce the effectiveness of traditional radars, the "Sky Guardian" could establish autonomous protective networks along naval routes. For the protection of high-value assets like aircraft carriers or amphibious assault groups, a multi-layered "protection umbrella" formed by "Sky Guardians" would offer robust and cost-effective defense.

Future Prospects: Towards Defensive Drone Swarms

Looking ahead, the "Sky Guardian" could evolve into the concept of "defensive drone swarms." Current loitering munitions could transform into fully autonomous micro-drones with longer loitering times (1-2 hours) and more flexible maneuverability. These swarms could form an intelligent defense network, dynamically adapting their deployment based on the threat.

Further developments could include:

• A "hybrid attack capability" to counter not only anti-ship missiles but also drones, cruise missiles, and even surface craft.

• A "rapid ground deployment version" to support the air defense needs of important coastal facilities and temporary ports, further expanding the system's scope of application.

In summary, the "Sky Guardian" represents China's potential strategic response to the threat of next-generation anti-ship missiles. By adopting a proactive "area defense" approach and leveraging emerging technologies in "top-down" detection and autonomous engagement, the PLAN aims to rebalance the technological advantage in the maritime domain. While technical challenges are significant, the potential impact on Chinese naval defense capabilities would make this development a top priority.