Point Defense Missile Systems (PDMS)-MARITIME SECURITY FORUM
1. Introduction to point defense missile systems
Point defense missile systems (PDMS) are designed to protect valuable and critical assets against aerial threats, such as ballistic missiles, air-to-ground missiles, cruise missiles and drones. A PDMS includes sensors and a missile intercept system. Radar sensors can be multi-functional or dedicated to target tracking. Based on radar discrimination, the command and control (C2) system issues engagement orders and launches the missile from a vertical launch system, either naval or ground-based. The intercept system relies on on-board guidance and PDMS radars for accurate threat interception.
Several countries are developing PDMS to protect against various air threats. A PDMS is needed to protect important fixed installations, such as oil refineries and power plants, because long-range radars are not sufficient. Thus, these systems are essential to counter aerial threats from adversaries.
1.1. Definition and purpose
The need for Point Defense Missile Systems (PDMS) to protect critical assets such as ships, airports, and command centers against missile attacks is widely recognized. This chapter addresses the historical background, need, objectives, and scope of PDMS study. A missile defense system consists of three main components: sensors, interceptors, and command and control systems (Fontana and Di Lauro, 2022).
Sensors detect threats to track, predict trajectory, and control interceptors. Interceptors are the elements designed to destroy these threats. Current missile defense systems use other missiles as interceptors. Typically, interceptors are not equipped with an explosive warhead but rely on kinetic energy to neutralize a threat. These interceptors are called kinetic interceptors and generally have higher speeds than the threats they are trying to intercept. To achieve interception, the sensor system must initially detect the threat. Once detected, the command and control system launches an interceptor. The interceptor takes time to reach the threat, so the distance it must travel before neutralizing the threat is significant. Tracking and prediction of the threat trajectory is essential, given the limited maneuverability of interceptors. After launch, an interceptor can make only minor course corrections, emphasizing the importance of accurate threat trajectory calculation. Missiles can be detected in various phases of their flight. A typical missile defense scenario involves the detection, tracking and interception of a threat missile by a missile defense system.
Threats usually possess advantages over defenses. Interception success is maximized when certain conditions are met. Interception should be carried out as early as possible. A hit between the launch and impact points is more likely to succeed if the distance between these points is minimal. The interception should also be made at a steep angle and should be effective even in the presence of maneuver or countermeasures.
1.2. Historical evolution
Missile defense has its origins in the Cold War, when the Soviet nuclear threat became evident. The US created the Triad to deter this aggression, but Soviet investment in anti-deterrent systems prompted the US to contemplate a deeper defense. Interceptions were planned against SLBM bombers and submarines as well as ICBMs.
In 1963, President Kennedy proposed protecting the US with nuclear ABM systems, leading to the ABM Treaty of 1972. In the 1970s, the US focused on space systems research, largely abandoning terrestrial plans. However, research on hit-to-kill systems continued into the 1980s.
2. PDMS components
PDMS are designed to protect valuable assets such as ships, airfields or command nodes. A PDMS includes sensors, coordination networks, command and control units and interceptor missile launchers. Detection and tracking of missiles is done by two-dimensional radars, and sometimes 3D radars and electro-optical sensors are used for longer ranges. After detection, the data is sent to the command unit which calculates the engagement coordination. PDMS can operate autonomously or manually, managed by operators (Fontana and Di Lauro, 2022).
2.1 Missile interceptors
Next we can analyze the missile interceptors used in point defense missile systems (PDMS). PDMS missile interceptors are classified into two categories based on the target engagement method: semi-active guidance and inertial guidance. In semi-active guidance, information about the target’s course and velocity is brought on board the interceptor using its own sensors after launch. In inertial guidance, the pre-programmed flight path is followed by the interceptor using only the initial target data (Fontana and Di Lauro, 2022).
2.2 Radar
Radar systems are central to modern PDMS, detecting and tracking threats. These systems provide critical information to interceptor missiles and the fire control system. Radars are categorized by the type of waves (continuous, pulsed, semi-active) and the frequencies used (ultra-high, super-high, extremely high). Most PDMSs use active, semi-active, and passive RF radars, operating at super-high and very high frequencies (Fontana and Di Lauro, 2022).
Fire control radars (FCR) rely on active and semi-active missile guidance, tracking threats with active or external radars. Missiles are guided to the target by reflected energy. Some PDMS use semi-active IR/EO systems, which track threats and guide missiles by reflected IR energy.
2.3. Fire Control Systems
Point Defense Point Defense Missile Systems (PDMS) can use passive tracking for airborne targets detected at long ranges or active tracking for hidden threats such as cruise missiles (Shin, 2012). Active radar systems provide situational awareness and the ability to track multiple targets, but require complex signal processing. In contrast, infrared (IR) systems are simpler but can be ineffective for low-flying targets in complex environments (Fontana and Di Lauro, 2022).
PDMS design involves choosing sensors, trackers, guidance laws, and missile configurations for optimal performance, with an eye toward minimizing misses and maximizing successful intercepts. Cooperative guidance can improve system performance under certain conditions.
3. Types of point defense missile systems
Point defense point defense systems can be categorized according to the types of interceptors, the basis of target tracking and illumination, and the methods of launching interceptors. Four types of PDMS are generally found in the literature, including weapon-based PDMS, missile-based PDMS, passive sensor-based PDMS, and active sensor-based PDMS (Fontana and Di Lauro, 2022).
Weapon-based PDMS uses high-velocity projectiles to intercept threats. Despite its relatively low kill probability, weapon-based systems have advantages such as small radar cross-section, low cost, and minimal reliance on external support. The C-RAM and Phalanx systems used by the US military are examples of weapon-based PDMS in widespread use. Missile-based PDMS uses guided missiles that can be categorized as command guided missiles or self-guided missiles. Command guided missiles depend on ground radar to illuminate the target. Although they offer a higher kill probability, they are heavily dependent on external support and interfere with airspace when used against aerial threats. Self guided missiles, on the other hand, use on-board seekers to detect, track and intercept targets.
3.1. Ground-based PDMS
PDMS with ground-based deployment options provide protection against short- and medium-range air threats to critical assets. They can be stand-alone systems with their own radars and C2 or use existing radars for point defense. The I-Derby solution exemplifies the first option, and the PDMS integrated with ELM-2288 radars exemplifies the second option.
The I-Derby missile system has been operational since 2007, with launches from the air and from the ground. Missiles can be launched with rail and canister launchers, using electro-optical trackers to engage targets. The system protects against aerial threats up to 100 km range using launch platform radar guidance and can integrate legacy radars for detection and tracking (Fontana and Di Lauro, 2022).
3.2. Naval PDMS
Naval PDMSs are smaller and lighter than land-based ones, mounted on ships to protect civilian or military personnel. They have a missile tracking range of more than 60 km and are mainly used for defense against air threats. The systems can be stand-alone, with their own radar, control center and launchers, or integrated with other ship systems.
The simplest naval PDMS configuration is a stand-alone system with fixed or rotating radar, depending on the design. These are installed on lighter ships to provide protection against aerial threats, with a tracking range of over 60 km and limited to 1.5 km when engaging missiles.
4. Operational effectiveness and case studies
PDMS (Point Defense Missile Systems) are ground- and tower-mounted air defense systems integrated with sensors, command and control, engagement and fire control functions on a single platform. They provide day and night air defense against aircraft, helicopters, UAVs and precision guided munitions (PGMs).
Studies on PDMS include technological progress, operational effectiveness and emerging trends. Advances in PDMS sensors, missile technology, and associated subsystems are discussed, as well as their effectiveness against various air threats, analyzing diverse air defense strategies.
PDMS systems can operate autonomously or in a networked air defense environment using shared target data and C2 (command and control) information. The multi-function surveillance radar tracks aerial targets and delivers them to the fire control radar for guidance and final tracking.
The PDMS can launch short-range (5 km) to long-range (70 km) missiles, complementing the SHORAD and SSA systems. Recent advances in missile technology and the integration of multi-sensor networks have improved PDMS capabilities to counter air threats.
4.1. Successful systems
Israel’s Iron Dome missile defense system can intercept short-range rockets, artillery and mortars at a cost per interceptor of between $65,000 and $130,000. Rockets from Gaza are fired continuously and 85% of Iron Dome missiles are fired after a failed intercept. A study showed that dropping low-value targets for more important intercepts improves performance. Random target schemes lead to longer intercept times, and fixed interceptor assignments are not effective. With 3 interceptors per target, almost all missiles would be intercepted, but this can lead to misallocations in the presence of multiple targets. Prioritizing the remaining targets is the most efficient method (J. Pella, 2018).
The Aegis PDMS system targets anti-ship missiles, ballistic missiles and aerial threats. A single threat detected by a radar is handled by a specific interceptor, and an additional radar takes over if the first intercept fails. Most tests were conducted without external data. Random target assignment schemes work well, but cooperative tracking requires many available sensors and interceptors to be effective.
4.2. Problems and constraints
PDMS exhibits a specific adherence to the weapons approach. Kill-chains cost money and take time; the number of intercepts in each segment of each kill-chain is planned on the PDMS launch platforms, given the defensive areas these plans defend. Thus, target missiles must be chosen very carefully, and failure scenarios are analyzed for each possible failure of these missiles (Fontana and Di Lauro, 2022). General difficulties prevent this illicit selection at present.
Forward sprays against LEO targets involve PDMS radars with their own bandwidth, which severely limit standoff distances and elevation angles. Even so, the use of PDMS in this context would be attractive if it were not for the current limitations related to the expense of PDMS launchers and calculations demonstrating low probabilities of success.
One of the rudimentary PDMS systems has been applied in the simplest way (J. Pella, 2018). The inconsistent state of experiments for hypersonic PDMS threats makes the estimates globally secret. Hybrid threats targeting critical functions involve combinations of airplanes, standoff weapons, and drones. Using brute force PDMS against these threats rarely produces effective results. Alternatively, each category of investment in air, ground, or space systems suggests that hypersonic PDMS threats are vulnerable.
Ballistic mitigation is becoming increasingly complex and expanding into space.
5. Expected future trends and innovations
Recently, Point Defense Point Defense Missile Systems (PDMS) have become a topic of interest due to the growing aerial threat to important facilities and assets. PDMS provide protection against various types of threats such as cruise missiles, artillery shells and aircraft. PDMS is an autonomous, missile-based air defense system designed to protect critical assets against multiple uncontained air threats. The system performs the entire process from threat detection to threat neutralization, using on-board sensors for in-flight tracking and guidance. It can complement existing air defense systems, providing a final line of defense in a layered structure. PDMS is designed for 360-degree protection against aerial threats. The main subsystems of the PDMS include surveillance and tracking radars, fire control radars (FCR), electro-optical sensors, command and control system, and vertically launched missiles with appropriate guidance systems. The PDMS missile system is based on a network-centered architecture and is capable of both autonomous and remote operation. In autonomous mode, the system performs target engagement independently. In remotely controlled mode, only the detection and tracking radars act independently and target engagement is performed by an external command and control system. A PDMS can detect and track a threat from a distance of more than 25 km, depending on the type of threat, and can launch a missile against it at ranges of more than 10 km (Fontana and Di Lauro, 2022).
HOW DOES IT WORK PATRIOT AIR & MISSILE DEFENCE SYSTEM
References:
Fontana, S. and Di Lauro, F. “An overview of sensors for long-range missile defense”. (2022). ncbi.nlm.nih.gov
J. Pella, P. “The continuing quest for missile defense: when lofty goals meet reality.” (2018) [PDF].
Pugacewicz, T. “Missile defense roles in U.S. post-Cold War strategy”. (2017). [PDF] [PDF]
Shin, H. S. “Study on cooperative missile guidance for area air defense”. (2012). [PDF] [PDF]
Park Sung-hwan “A study on propulsion system design for ship operation”. (2013) [PDF] [PDF]
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