YDG-61
| YDG-61 | |
|---|---|
 YDG-61G (infrared only) and N (infrared with passive radar) | |
| Type | Surface-to-air missile |
| Place of origin | Menghe |
| Service history | |
| In service | 2001-present |
| Production history | |
| Unit cost | $350,000 |
| Specifications | |
| Weight | 64 kg |
| Length |
|
| Diameter | 140 mm |
| Warhead | 18 kg |
Detonation mechanism | radio proximity fuse |
| Engine | solid fuel rocket motor |
Operational range | 8 km |
| Speed | 650 m/s (Mach 1.9) |
Guidance system | Infrared homing with passive radar homing on N variant |
The YDG-61 (Formal designation: 61식 대공 유도탄 / 六一式對空誘導彈, ryuk-il-sik daegong yudotan, "Type 61 anti-air missile;" Short designation 유대공-61 Yudaegong-ryugil "YDG-61") is a short-range surface-to-air missile developed in Menghe and used by its Army and Navy. It uses infrared guidance guidance, combined with a passive radiometer on the "N" variant, to home in on the target, giving the missile true fire-and-forget capabilities. It is designed to be used against fixed-wing aircraft, helicopters, cruise missiles, anti-ship missiles, and guided munitions, providing short-range air defense for a front-line unit, high-value land target, or warship. It can be used either independently or as part of a combined gun-and-missile mount.
Development
In 1980, the Democratic People's Republic of Menghe introduced the YDG-35 infrared-homing missile, a near-exact copy of the 9M37 developed in Letnia. While using infrared guidance, it was considerably larger than MANPADS missiles like the YDG-31 and YDG-34. In the Menghean People's Army, it served as the main armament of the tracked JYDG-35 surface-to-air missile system.
By the 1990s, however, it was becoming clear that the YDG-35 was inefficient against modern helicopters and fixed-wing aircraft, hampered by poor range, low accuracy, and high susceptibility to flares. This led the Menghean Army to submit a design request for a successor design, which would fill the same role while incorporating seeker improvements and a longer range. The Menghean Navy also expressed interest in a new short-range surface-to-air missile for its warships, as the YDG-36 (with both radar-guided and infrared-homing variants) had proven inaccurate and unreliable in trials.
Under the MoND's combined procurement scheme, the two requirements were condensed into a single development program, with the goal of supplying both branches with a single missile system. Testing was conducted during the mid-to-late 1990s, and the system entered service with the Army and Navy in 2001.
Characteristics
YDG-61G
The YDG-61G is the basic infrared homing variant of the missile, developed for use in the Menghean Army. Its seeker incorporates developments from the YDG-38 MANPADS, including two-color sensitivity. This allows all-aspect engagement of targets, achieved by tracking the warm fuselage if the engine exhaust is not visible, and enables the missile to distinguish between flares and aircraft. The YDG-61's seeker, however, is much larger than that on the YDG-38, and can detect targets at nearly twice as great a distance.
An advantage of the YDG-61G is that it does not require radar illumination from the ground target, protecting the launcher from anti-radiation missiles and radio-frequency jamming. Fire-and-forget guidance also allows the launch platform to retreat behind cover after firing, or move on to another target. The missile is, however, limited by its size and weight, which make it too bulky to be man-portable, and by its relatively short range compared to radar-guided missiles. In particular, its seeker must acquire the target's infrared signature before launch, and high attenuation of infrared radiation in the lower atmosphere can limit the range at which this is possible - especially in inclement weather conditions.
YDG-61N
The YDG-61N carries a revised guidance section, easily identifiable by two "prongs" projecting forward on opposite sides, and is used by the Menghean Navy. These are the antennas of a passive radiometer, designed to home in on RF signals emitted by radar-guided anti-ship missiles. During the terminal stage of the approach, the YDG-61N switches to its infrared seeker, which can more precisely determine the target's location. The missile can also be programmed to rely on infrared guidance only for the entirety of its flight path, but because the infrared seeker was reduced in size to save space and weight, it has a reduced acquisition range.
The YDG-61N also incorporates a revised fuse section with a shorter proximity range, allowing it to be used more effectively against sea-skimming anti-ship missiles. During the launch procedure, the operator may also choose to disable the proximity fuse and rely on a direct impact, allowing the missile to engage very-low-altitude missiles or small surface craft.
Apart from the guidance and fusing sections, the rest of the missile is fully identical, facilitating parts commonality in production and maintenance.
In 2018, the Chŏnggong Design Bureau reported that it would begin work on a revised variant of the YDG-61N that can cross-reference information from the passive radiometer and IIR seeker during the terminal stage. This would allow it to distinguish between radar-guided anti-ship missiles and any decoys they may have ejected, a feature rumored to be in development in some other navies in Septentrion. Some sources have provisionally labeled this missile YDG-61D, though as of yet it has not been issued an official designation.
HYB-61/24 Bŏdŭl
The HYB-61/24, also marketed as Bŏdŭl (Menghean: 버들, "willow") is a missile-based close-in weapon system using the YDG-61. It is commonly seen on warships of the Menghean Navy. It is capable of using both missile types, but in practice it is almost exclusively loaded with the YDG-61N. The missiles are carried in six quad-missile boxes, three on each side of a central pedestal. There is no automatic reloading system - missile boxes must be reloaded in port or with the help of an alongside replenishment ship - but with 24 ready missiles, the ready capacity is comparable to the RIM-116 and other similar systems.
The missile complex is aimed remotely from the ship's combat information center. It relies on the ship's onboard search radar or ESM systems to determine the bearing to the target; a dual-mode infrared and visual camera on the center of the mount then finds and tracks the target on that bearing. If the EMCON state permits it, a radar antenna on the mount briefly illuminates the target to confirm its range, speed, and bearing. Otherwise, the missile can be fired directly at the target's infrared signature.
Because the YDG-61N is a fire-and-forget weapon, the launcher can rapidly move on to the next target after engaging the first, or the ship can deploy chaff and IR-blocking smoke once the missile has been fired beyond its range.
The Bŏdŭl system is fully enclosed on its pedestal, meaning that it does not require any below-deck supporting systems and can be bolted directly onto the ship's deck, as long as it is connected to the search radar and the CIC. This makes it ideal for small surface combatants, or for export to foreign countries.
Dungji CIWS
The Dungji and Dungji-R CIWS systems, designated GBM-23/5Y and GBM-23/5YR respectively, both use the YDG-61 surface-to-air missile. Both consist of a GBM-23/5 Bulkkot gun-based CIWS turret with two quadruple elevating YDG-61 launch boxes attached to each side. This gives two-thirds of the missile capacity of the Bŏdŭl mount, while also adding gun-based capability for short-range defense. The Dungji and Dungji-R mounts differ only in that the latter also has a short-range air search radar.
Subisu CIWS
The Subisu CIWS system consists of a special turret with two 5-barrel 23mm rotary cannons and two quad-tube YDG-61 boxes. These launch boxes can be reloaded via a magazine below the ship's deck, with a total of 32 missiles carried.
Land-launch platforms
JYDG-61/8
The JYDG-61/8 is a dedicated self-propelled launch platform for the YDG-61. It is based on the low-profile variant of the BSCh-6 APC hull. The three-man crew consists of a gunner, a driver, and a commander, who sit side-by-side in the front of the vehicle. The turret itself is remotely controlled, as is the optics system.
The vehicle carries eight missiles in total on a rotating pedestal launcher equipped with an electro-optical tracking sight and a small radar dish for checking range. The launch array can elevate to +60 degrees. It is exclusively designed to carry the "G" variant of the missile, without passive radar prongs. No reloads are stored on the vehicle, but they can be brought forward by a resupply unit in the close air defense battalion.
A larger optics assembly forward of the turret allows the commander to scan the skies for aircraft, extending targeting range to make the most of the missile's range; over the rear 90-degree arc, the gunner can still scan independently with the turret's electro-optical sight or receive targeting cues from a separate search radar. Mounted co-axially with this optics turret is a 7.62mm GCh-77 machine gun, which can be used for self-defense against infantry or (minimally) against helicopters within the system's .6-kilometer minimum range.
As it does not rely on radar for targeting - the dish on the launch array only activates briefly to check range, and can be deactivated - the JYDG-61/8 is not vulnerable to anti-radiation missiles or radar jamming. This makes it more survivable in an environment where enemy forces possess air parity and are conducting a heavy SEAD campaign. Nevertheless, short range and lack of a secondary gun option make the JYDG-61/8 a last-line weapon for air defense.
Each battery of JYDG-61/8 launch vehicles is supported by a single JDGR-620 self-propelled air search radar with IFF interrogator. This system can detect a fighter-sized object at 34 kilometers, allowing adequate time to cue nearby launchers to the target. It has a crew of seven, and also serves as the battery command post. A later variant, JDGR-620N, adds a MChGJ-0802 C-band radio antenna, allowing secure communication between battery components.
All battery components share extensive parts commonality, can maintain a road speed of 70 kilometers per hour, and are fully amphibious.
DGJP-230N
In addition to the twin 30mm autocannon carried on all variants, the "N" variant of the DGJP-230 system carries eight YDG-61 surface-to-air missiles in two quad-cell boxes, one on each side of the turret. These extend the system's effective engagement range out to eight kilometers, and can be used while the onboard radar is deactivated for protection against anti-radiation missiles. This system is exclusively designed to accept YDG-61G missile variants.