YDG-61

YDG-61
YDG-61G and YDG-61N; note the different seeker configurations.
Type	surface-to-air missile
Place of origin	Menghe
Service history
In service	2001-present
Used by	Menghe
Production history
Designer	Chŏnggong design bureau
Designed	1994-1999
Unit cost	$350,000
Produced	2001-present
Variants	YDG-61G, YDG-61N, YDG-61D (under development)
Specifications
Weight	64 kg
Length	2.27 m (YDG-61G) 2.34 m (YDG-61N)
Diameter	140 mm
Engine	solid-fuel rocket
Operational range	8 km
Speed	650 m/s (Mach 1.9)
Guidance system	YDG-61G: infrared homing YDG-61N: infrared homing and passive radiometer
Steering system	aerodynamic surfaces

The YDG-61 (Menghean: 유대공-61, Yudaegong-61, abbr. for Yudotan, Daegong, "Missile, Anti-Air") is a lightweight 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.

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 the Federation of Socialist Republics. 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 Chŏnggong Missile Design Bureau to begin work on a generational improvement, which would incorporate seeker improvements and a more effective solid-fuel propellant. The missile was also rolled into a Menghean Navy project requirement for a new missile-based close-in weapon system for warships. Tests with the new missile were conducted in 1999, with service deliveries beginning 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.

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.

YDGB-61/12

The YDGB-61/12, also called "Willow" Menghean: 버들, Bŏdŭl) is a pedestal-type missile launcher for the YDG-61 missile, 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 boxes on either side of the launcher, for a total of twelve at the ready, and must be manually reloaded by the crew, a procedure usually conducted in port or with the help of an alongside replenishment ship. As a missile-based close-in weapon system, it can be used against incoming anti-ship missiles, as well as aircraft, helicopters, and light surface targets (when the proximity fuse is disabled).

The missile complex is aimed remotely from the ship's Combat Information Center. It is directed toward an incoming threat by means of the ship's onboard search radar, but in the presence of heavy jamming an electro-optical sight atop the launcher can perform an area search. This camera is also used to fine-tune directional instructions from the radar set. This process is semi-automated, though a weapons officer's authorization is needed to engage each target.

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.

The YDGB-61/12 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.

Launcher specifications

• Weight: 3,800 kg (loaded launcher)
• Height: 2.16 m
• Missiles carried: 12
• Reloading: manual
• Traverse speed: 30 degrees per second
• Traverse range: 360° (limited by ship's superstructure)
• Elevation range: -15° to +90°
• Deck penetration: n/a

Land-launch platforms

JYDG-61/8

File:JYDG-61-8.png

The JYDG-61/8 launch vehicle and optional JDGR-620 search radar.

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

Main article: DGJP-230 Jaebongtul

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.

See also

• List of Menghean missiles
• YDG-38
• YDG-64