YDJ-83
| YDJ-83 | |
|---|---|
| Type | Precision-guided glide bomb |
| Place of origin | Menghe |
| Service history | |
| In service | 2021-present |
| Used by | Menghe |
| Production history | |
| Designer | Gwon-u Industries Group |
| Designed | 2015-2020 |
| Unit cost | $172,000 |
| Produced | 2020-present |
| Variants | YDJ-83G YDJ-83N |
| Specifications | |
| Weight | 113 kg (YDJ-83G) 110 kg (YDJ-83N) |
| Length | 3.75 m |
| Diameter | 192 mm |
| Warhead | Tandem shaped charge with prefragmented blast sleeve |
| Warhead weight | 74 kg (total) |
| Wingspan | 1.35 m (extended) |
Operational range | 100 km |
Guidance system | CSNS and inertial |
Steering system | aerodynamic surfaces |
| Accuracy | claimed 1.2 meter CEP |
Launch platform | Songrim SR-8 Daesŭngri DS-9 Daesŭngri DS-10 Songrim SR-12 |
The YDJ-83 is a type of semi-autonomous air-launched precision guided munition based on the WYGP-100 Saehorigi. It shares the Saehorigi's tail section, containing a CSNS and inertial guidance unit with four control surfaces, as well as its folding rhomboidal wings below the bomb body (or above in flight). The warhead and nose unit, however, are entirely different, resulting in the application of an entirely different designation. Though technically a glide bomb due to its lack of built-in propulsion, the YDJ-83 is nevertheless designated as an "anti-ground missile" (yudotan, daegong) because of its sophisticated guidance system and primary reliance on direct-impact warhead effects rather than area effects.
The YDJ-83 is also known by the name Bidulgi, or "pigeon," possibly in reference to the renowned navigation abilities of homing pigeons.
Description (YDJ-83G)
The YDJ-83G has a tri-mode seeker unit in the nose, containing an active millimeter-wave radar antenna, a semi-active laser receiver, and an infrared contrast seeker. The base of the bomb also retains the CSNS and inertial guidance components of the WYGP-100, which are primarily used for mid-course guidance but can also be used for terminal guidance if needed. The multi-mode guidance system allows greater flexibility in the range of targets which can be engaged: millimeter-wave guidance performs better against moving targets, which are easier to distinguish from ground clutter, while infrared contrast imaging performs better against targets with running engines or targets heated by the sun.
The multi-mode seeker also allows different guidance options to cross-reference one another, improving resistance to jamming and changes in target movement. For example, if a nearby platform is able to illuminate the target with a shaky laser designator, the millimeter-wave and infrared contrast seekers can increase the hit probability by tracking the contact's heat signature and radar return. Likewise, if a moving target stops near ground clutter, the infrared seeker can take over from the millimeter-wave seeker. And if a target is lost altogether, the GPS and inertial guidance systems can continue leading the bomb toward the target's last known range and bearing.
Like the YDJ-82, the YDJ-83 is an optionally fire-and-forget weapon: it requires no additional input from the operator once released, but the operator can optionally feed it course correction information if the target moves or if a more valuable target is detected. It also has lock-on after launch capability, and can independently acquire a target's infrared, radar, or laser signature after being dropped toward the target's known approximate area. A datalink in the seeker head allows multiple nearby YDJ-83G units to share targeting information with one another: for example, if multiple bombs are homing in on a group of targets, the bombs can allocate targets such that each target is locked by at least one bomb.
In contrast to the WYGP-100, which has a ground-penetrating high-explosive bomb body as its warhead, both variants of the YDJ-83 have a tandem HEAT charge with a prefragmented outer sleeve. The tandem charge increases performance against reactive armour, while the prefragmented outer sleeve spreads shrapnel over a wide area around the impact point. This multi-mode warhead allows the YDJ-83 to defeat both heavy armored vehicles and light area targets, and is especially useful if the bomb loses its lock on a target but continues to home in on its last known location. Thus, in contrast to small-diameter guided munitions in other countries, which increasingly aim to minimize collateral damage, the YDJ-83 aims to maximize it: for example, striking both an IFV and the dismounted soldiers around it.
Comparison with WYGP-100
Though based on the same guidance and glide wing kit as the WYGP-100 Saehorigi, the YDJ-83G is designed to engage a different range of targets, and optimized around slightly different roles. Its more sophisticated multi-mode guidance system allows it to lock onto moving targets, which the Saehorigi cannot track. Additionally, the YDJ-83G can acquire stationary targets whose exact coordinates are unknown: for example, if an enemy missile launch reveals the approximate position of a SAM battery, but satellite images and forward platforms have not confirmed the exact positions of the launch vehicles within it. This also makes the YDJ-83G useful against self-propelled artillery vehicles and missile TELs performing shoot-and-scoot missions, as the projectile has a high chance of detecting enemy vehicles as they exit the firing position.
Compared with the WYGP-100, however, the YDJ-83 does have certain drawbacks. While its shaped-charge warhead can penetrate concrete, brickwork, and earth, it has less ground penetration capability than the WYGP-100. It is also much more expensive: export contracts and cost estimates place its manufacturing cost at roughly five times that of the WYGP-100. Thus, while the YDJ-83 can be programmed to rely entirely on CSNS and inertial guidance to attack a fixed soft target, a WYGP-100 could achieve the same results at a much lower cost.
| WYGP-100 Saehorigi | YDJ-83 Bidulgi |
|---|---|
| CSNS and inertial mid-course and terminal guidance | CSNS and inertial mid-course guidance with terminal active mmW, infrared contrast, and semi-active laser guidance |
| Unitary 100kg ground-penetrating warhead and contact or airbursting fuse | Tandem HEAT warhead with prefragmented outer sleeve and contact or airbursting fuse |
Optimal targets:
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Optimal targets:
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YDJ-83N
The YDJ-83N is a dedicated anti-radiation version of the YDJ-83. It has a smooth, opaque nosecone which contains a wide-spectrum passive radio receiver array. In addition to enemy air-search radar and radar guidance installations, it is also able to home in on radar jammers, GPS jammers, and radio communication jammers. If the radiation source switches off, the YDJ-83N reverts to CSNS and inertial guidance to slow its descent and continue homing in on the signal's approximate area of origin. If the YDJ-83N reaches the radar site's approximate area of origin but still detects nothing, it will fall into a descent-minimizing holding pattern, effectively functioning as a loitering munition.
Because it lacks a rocket motor, the YDJ-83N is less expensive than a conventional anti-radiation missile. Its loitering capability also makes it more useful against radar sites which can be switched on and off with ease. In flight, it is effectively identical in radar returns and trajectory to a YDJ-83G or WYGP-100, making it difficult for a radar operator to determine whether the radar site is under conventional guided munitions attack (in which case the solution is to illuminate the incoming projectiles) or anti-radiation missile attack (in which case the solution is to shut off radar emissions). Compared to a conventional anti-radiation missile, however, the YDJ-83N has less range on most launch profiles and takes longer to reach the target.
Launch platforms
The YDJ-83 has an identical bomb lug and data bus interface to the WYGP-100, and has nearly identical external dimensions, save for its slightly shorter length. It can be released from all specialized WYGP-100 multiple carriage bomb racks, as well as individual hardpoints for sub-1000-kilogram-class bombs. The Menghean Army has also tested multiple carriage units with a mixture of YDJ-83G, YDJ-83N, and WYGP-100 bombs.
Like the WYGP-100, the YDJ-83 can only be launched by fixed-wing aircraft in forward flight, and its range depends on the launch platform's velocity, altitude, and rate of climb. Official factsheets published by Gwon-u claim a range of 100 kilometers, though it is not clear what flight conditions this figure requires and whether it can be extended with high-altitude supersonic climbs. Maximum range is likely to be much lower when released from a medium-altitude loitering drone.