Jŏgran-un (countermeasure)
| Jŏgran-un | |
|---|---|
| File:Jogran-un full system.png A color-coded diagram of the Jŏgran-un system's components on the JCh-5.5N main battle tank. | |
| Type | Active protection system |
| Place of origin | Menghe |
| Service history | |
| Used by | Menghe |
| Production history | |
| Designer | Chŏnggong Missile Design Bureau |
| Designed | 2008-2016 |
| Unit cost | $100,000-$200,000 (est.) |
| Produced | 2016-present |
Jŏgran-un (Menghean: 적란운 / 積亂雲, "cumulonimbus") is a type of active protection system intended for use on military vehicles. It was independently developed in Menghe during the early 2010s, and first displayed to the public in 2016. It is designed to protect heavy armored fighting vehicles against armor-piercing threats, and is effective against top attack munitions and kinetic energy penetrators as well as conventional anti-tank rockets and ATGMs.
A less sophisticated system, designated Ulsae (울새, "Robin"), incorporates only the passive softkill components of the Jŏgran-un suite, namely, the infrared missile approach warning sensors, laser warning receivers, infrared jammer, and automated smoke release system, but not the radar panels or Chŏndongsuri projectiles. This system was introduced in 2010.
Development
Menghean interest in an active protection system began in the mid-2000s, when a defense company in Dayashina offered to export units of a hardkill active protection system to Menghe. Representatives of the Menghean Army immediately turned down this proposal, arguing that the system would be expensive to deploy and unreliable in combat. While official complaints cited cost as the main concern, deeper opposition stemmed from entrenched and sometimes irrational attitudes among officers in the Armored Corps, including complaints that an active protection system was a "cowardly measure" or that it would give tankers a false sense of invincibility.
As time passed, however, military interest in an active protection system steadily increased. One cause of concern was the proliferation of top attack munitions, which were much harder to armor against; other concerns related to the steady climb in cost of Menghean main battle tanks, mainly due to the inclusion of more accurate fire-control systems. During this same period, the Menghean Army was gradually purging its upper officer corps of conservative political appointments, and replacing these with a new generation of officers intent on modernizing the armed forces. This faction strongly endorsed the development of an active protection system for tanks.
Around 2010, the Ministry of National Defense is believed to have issued a requirement for a hardkill missile defense countermeasure for armored vehicles. In order to keep costs low, the program required a per-unit production cost of under ₩ 2 million (about $100,000). At the same time, however, the MoD also insisted that all development take place domestically, even though importing foreign systems would have been cheaper.
The Chŏnggong Missile Design Bureau, which normally specializes in radar systems and surface-to-air missiles, was chosen to handle development of the system. Design work appears to have started in 2012, though some sources claim an earlier date. Initial development was relatively slow, but acquired new importance after the Innominadan Crisis, during which JCh-6 tanks suffered unexpectedly high losses to RPG fire. Throughout this period, the very existence of the APS program was considered a state secret, and the full suite was not unveiled to the public until the 2016 National Day parade in Donggyŏng.
Components
Contrary to some initial foreign reports, the Jŏgran-un is not a single hardkill charge projector, but a layered, integrated system of countermeasures. These include radar panels, passive infrared sensors, active infrared dazzlers, and automated smoke grenade projectors, as well as the charge projector itself. The entire array functions as a single system, selecting the optimal countermeasure for each identified target and adapting its responses if earlier measures appear ineffective.
Detection
The Jŏgran-un defensive complex relies on two layered detection systems to identify and engage incoming threats. The first is a set of passive infrared sensors, which are programmed to automatically identify the backblast of a projectile launch and the flare of an incoming rocket or missile. This system is reportedly effective out to a range of 5,000 meters, depending on the type of projectile. Some sources claim it can also pick up the signal from laser designators and laser rangefinders, allowing the target vehicle to determine whether it is being targeted before a launch takes place; this was officially verified in 2019.
The second layer of detection comes from fixed radar panels which, in combination with the infrared sensors, measure the speed, bearing, and flight path of an incoming projectile. These are capable of distinguishing probable incoming threats from birds, ground clutter, small-caliber fire, outgoing friendly projectiles, and incoming projectiles which will not strike the tank. Reportedly, they also have a limited ability to distinguish between types of threats, using a combination of flight path, velocity, and radar cross-section.
If a probable incoming threat is detected, this information is sent to a central targeting computer, which calculates the incoming projectile's trajectory and assesses its type, then uses this information to determine the correct response. It also alerts the tank commander to the direction of the incoming threat, allowing him to engage the launcher or retreat into a covered position. All of this takes place in a small fraction of a second.
Softkill countermeasures
The softkill component of the Jŏgran-un system consists of two defensive layers, one based on jamming and the other based on concealment. It appears to use the same components as the "Ulsae" system first seen on the JCh-6 main battle tank, which entered service in 2008. These countermeasures are only activated if the detection system determines that the threat is a subsonic guided missile fired from an adequate distance; otherwise, the hardkill system is used.
The first softkill layer is an infrared dazzler which is designed to blind the guidance system on second-generation SACLOS ATGMs. The second softkill layer consists of a bank of smoke grenade launchers on either side of the turret, which can project a multi-spectral aerosol smokescreen to obscure the tank and break contact with any illuminator for laser-guided missiles. The smokescreen can also be manually activated by the tank commander.
If these measures are unable to draw a guided missile off course, the Jŏgran-un system then prepares to intercept the threat using a hardkill projectile.
Hardkill countermeasures
The hardkill component of the system is designated Chŏndongsori (천둥소리), or "thunderclap." It consists of a set of single-use tube launchers, each containing an explosive projectile similar in shape to a mortar bomb. Sources differ on whether the projectile is detonated by a simple time fuse programmed by the targeting radar, or whether it has some type of proximity sensor designed to trigger detonation as it passes the incoming threat.
The Ministry of Defense claims that the hardkill charge uses a combustible outer shell and relies on blast pressure alone, limiting collateral damage to infantry nearby. This detonates or destroys projectiles with HEAT warheads, under conditions that prevent the penetrating jet from properly forming. In testing, it was able to induce as much as 40 degrees of yaw in incoming APFSDS projectiles, causing them to strike the armor at a poor angle and break on impact. Under these conditions, armor penetration of the projectile fell to about 50 millimeters of hardened steel plate, not enough to protect light vehicles but enough to make the difference between certain penetration and relative safety on tanks' side armor and certain IFVs' frontal armor.
The Menghean armed forces operate two delivery systems for the Chŏndongsori hardkill projectile. The more common consists of a trainable, elevating launcher with four tubes. The firing computer adjusts the angle and elevation of the trainable launcher to match the trajectory of the threat, and fires off a projectile as the range closes. Each launcher can rotate over a 270-degree arc and elevate from -15 to +85 degrees, allowing the system to engage approaching top-attack missiles.
The second system consists of Chŏndongsori hardkill launchers which are fixed in place at a level angle, usually in a ring around the turret's frontal arc. This system has been seen on the Marine Infantry's SCh-5/6B main battle tank, and on experimental units of the BSCh-5HSD amphibious IFV, designated BSCh-5HSD1. In both cases, they are used in combination with the trainable quad-tube launcher. According to the Ministry of Defense, these are designed to fire in the path of incoming kinetic energy projectiles and man-portable anti-tank rockets. Compared to the trainable launchers, these offer a shorter reaction time and more stored projectile-defeats, though they cannot engage top-attack munitions or threats outside their fixed angles.
Based on comparison with similar systems, defense analysts have estimated that the hardkill portion of the Jŏgran-un system has a reaction time of 300 to 500 milliseconds, including the time required to detect the threat, determine its trajectory, and traverse the launcher. This would give it a minimum engagement distance of 150 meters against RPGs and 800 meters against APFSDS rounds, using the more conservative figures. Reaction time for the fixed launchers would be considerably shorter.
Ulsae softkill APS
Ulsae (robin) is the designation given to an active protection system containing only the softkill elements of the Jŏgran-un system. Foreign intelligence initially believed it to be a separate precursor system, but Menghean defense brochures released in 2018 confirmed that it originated when Changgung assembled a softkill-only system from the existing components of the Jŏgran-un system still in development. The Ulsae system first entered service in 2010, and is more widely used than the full Jŏgran-un system.
Deployment
The Jŏgran-un system was first unveiled to the public on July 27th, 2016, at the Victory Day Parade celebrating the 52nd anniversary of the end of the Menghean War of Liberation. At that parade, it was carried by JCh-5.5N tanks of the Marine Infantry. These vehicles apparently represented an early batch of the Jŏgran-un system, which was only in limited production at the time. Full-rate production of the system on new JCh-8 main battle tanks began in 2019, and even then, not all JCh-8s received the system, with refits on existing tanks instead receiving priority.
In contrast to other systems developed for the Menghean Army, the Ministry of Defense has stated that it has no plans to export the Jŏgran-un active defense system in the near future, claiming that the design is highly advanced and that if sold to other countries its components might be vulnerable to rival countries' spies. Even in Menghean service, tanks carrying the Jŏgran-un are rumored to be subject to tighter security, though they have also been seen on exercises.
Some foreign intelligence agencies have speculated that the current restriction on exports may be a function of the Jŏgran-un's technological immaturity. The system is relatively new and uses a high share of domestically designed components. The Army's decision to begin deployment with small-scale orders may also reflect concerns over reliability, and could be part of an effort to limit the expansion of potential sunk costs in case a full replacement of the system is deemed necessary.
Vehicles using the system
This list identifies Menghean military vehicles which have been seen with the Jŏgran-un system in active service as of 2022. It excludes testbed and prototype vehicles. The letters in parentheses indicate the variants which are fitted with the Jŏgran-un system. Letters marked with an asterisk (*) indicate that this variant only carries the Ulsae softkill APS.