Dyura radar

An Insŏng-class destroyer with sensors and electronics highlighted and labeled. There are three Dyura-D illumination radars, two over the main superstructure and one at the front end of the aft funnel.

Dyura is a family of multi-function sector search and fire-control radars produced in Menghe by Samsan Defense. It includes the long-range Dyura-D, the medium-range Dyura-J, and a compact Dyura-S, which as of 2023 has not entered service and appears to have been cancelled. All radar assemblies in the family use the same set of modular I-band antenna units, assembling them into active electronically scanned arrays of varying sizes. Because the AESA configuration allows smart processing and multiple beamforming, it is possible for a single array to simultaneously illuminate multiple targets or perform multiple missions.

Development

The Dyura radar family was developed by Samsan as part of an MoND requirement for a new destroyer class. The basic requirements called for a trainable illumination radar combining the range of the STIR 2.4 HP with the multiple beamforming capability of the CPAR-X single director recently licensed for the Chunchŏn-class frigates. Parallel development work on the YDG-67 missile also justified an extension of the desired maximum tracking and illumination ranges.

Originally, the high-power Dyura-D model was intended to have ballistic missile defense capability, as part of the Insŏng-class destroyers' BMD role. This requirement was dropped in late 2014, when the MoND fully removed ballistic missile defense from the Insŏng class's desired role set. Some sources speculate that the Dyura-D antenna can restore ballistic missile tracking capability through a software update, but this is not confirmed, and current (2023) brochure materials by Samsan do not list ballistic missile defense among its roles.

Operation

All radars in the Dyura family are based on a common set of active electronically scanned array technologies, which can be scaled to meet a varying set of requirements. This scalability is accomplished using antenna modules measuring 30cm wide by 50cm tall, a concept borrowed from the AN/SPY-6 when Menghe and Dayashina were exchanging information on its development.

By exploiting AESA operating principles, the Dyura radar is able to perform a wider array of functions than earlier fire control radars. A single antenna is also able to perform multiple missions simultaneously, at the cost of splitting power between multiple beams and thus reducing output. Officially confirmed missions of the Dyura radar system include:

• Volumetric air search across a 120-degree sector;
• Focused air search within an assigned bearing range;
• Missile guidance for semi-active radar homing missiles;
• Fire control for gun and autocannon fire against airborne targets;
• Fire control and shell correction for naval gunfire against surface targets;
• Radar jamming over a wide area; and
• Focused jamming of a specific target or targets.

The focused air search mode means that even if a Dyura radar unit receives only approximate target coordinates, or even an approximate target bearing, from another sensor or platform, it is able to perform a focused search of those coordinates. This is useful for the following capabilities:

• Acquiring targets which another platform detected, using information transferred via datalink.
• Confirming, at higher resolution, a target picked up by a lower-frequency shipboard radar.
• Verifying and tracking stealthy or low-RCS targets with weak returns on other sensors.
• Dismissing false contacts generated by other sensors.
• Generating range and velocity data for contacts detected by passive sensors, such as radar antennas in passive mode, ESM antennas, and IRST sensors like the Menghean Navy's Hongmoja.

By combining focused air search with sidelobe cancellation and other electronic counter-countermeasures, the Dyura antenna is able to generate detailed tracking information on a single contact or group of contacts within a selected narrow band, without alerting any hostile radar antennas more than a few degrees off the centerline of the search bearing. This is useful when operating under conditions of partial radio and radar silence, when a ship's only sources of target tracking information may be passive sensors and target tracks transferred via datalink from an airborne early warning platform.

Somewhat curiously for a shipboard phased array radar, the Dyura is typically situated on a trainable mount, rather than being directly integrated into the ship's superstructure. In this respect, it is similar to the CPAR-X director seen on the Chunchŏn and early Sŏnsan-class frigates. Compared to a fixed 3- or 4-array setup, this configuration reduces costs, and allows the ship to traverse its Dyura radar mounts as required by the threat environment. A 2-mount Dyura system cannot achieve simultaneous 360-degree coverage, and because of blind spots created by the superstructure toward the antennas on the forward superstructure, even the Insŏng-class destroyers cannot position their Dyura-D mounts to achieve simultaneous 360-degree coverage. This tradeoff is preferable when threats are likely to appear along a specific threat axis or set of threat axes, but suboptimal against threats approaching simultaneously from a wide set of directions.

In addition to the radar array itself, the Dyura-D and Dyura-J mounts both incorporate an electro-optical sensor with visual and infrared lenses. On the Dyura-D, this sensor is located on top of the mount and can traverse and elevate independently; on the Dyura-J, it is located on the left side of the mount and has elevation but no independent traverse controls. In clear conditions and at short ranges, this sensor allows the operator to achieve visual confirmation of a target, either in addition to radar tracking or while the radar is not emitting. Because these electro-optical units appear less sophisticated than the ones in the Hongmoja and Pigan systems, and because the Dyura-D and Dyura-J mounts are not designed to spin at high speed, these electro-optical sensors are likely not capable of performing horizon or sector scans.

Variants

Dyura-D

This is the largest type of Dyura illuminator currently in service, with 24 antenna modules. Menghean state sources claim that it is able to track and illuminate a Rafale-sized target beyond the maximum range of the YDG-67 missile, implying a distance of at least 360 kilometers and possibly much more. It is mainly used for long-range surface-to-air missile guidance, precise discrimination of stealthy targets, and high-powered jamming in the I and J bands.

Dyura-J

This is the medium antenna size, with 11 antenna modules. Menghean state sources list the instrumented range as 150 kilometers, the same as that of the CPAR-X director. It is primarily intended for use with the YDG-60, YDG-64, and YDG-66 missiles. It is also able to illuminate targets for the YDG-67, and although it is unable to exploit that missile's maximum range, it can additionally provide terminal guidance for YDG-67 missiles launched from another warship.

Dyura-S

This is the smallest radar mount in the Dyura family, with six antenna modules. It was developed to fill the same role as the STIR 1.2 on smaller surface combatants, providing fire control for both short-range surface-to-air missiles and a 76mm gun or 35mm autocannon. As of 2023, it is still in development, possibly due to challenges in integrating it with the guided rounds fired by the HP-76/1Y gun turret. Recently commissioned Menghean warships sporting 76mm guns have instead been spotted with Type 119 directors, which were developed by the Menghean Navy's in-house research facilities.

Used on

• Insŏng-class destroyer (Dyura-D)
• Chŏngsŏng-class frigate (Dyura-D)