Naval Weaponry of The People's Liberation Army Navy - Sonars

Sonars

Chinese sonar systems were initially based on Soviet supplied system, and during 1980's, some western sonars were also imported, including Italian DE-1160, French DUBV23/43, SS-12, HS-312 etc. Domestic Chinese sonars includes:

SJD-1

H/SJD-1 sonar is an indigenously developed bow mounted sonar, first of its kind in China. Initial proposal of adopting Soviet Tamir-11(MG-11, NATO reporting name Stag Hoof) search light sonar was rejected, because it was not considered adequate enough due to its single beam search capability, which means the low speed of search cycle would easily loose targets. A more capable indigenous Chinese sonar was ordered to be developed, with Mr. Huo Guozheng (霍国正) named as the general designer. The resulting indigenous Chinese domestic sonar was SJD-1 low frequency (LF), high power, large aperture sonar with a cylindrical array (designated as Type 601 sonar array), which was accepted into service after eleven major trials at the sea. Type 601 sonar array of SJD-1 sonar has a diameter of 2 meters, height of 1 meter and weight of 4 tons, and the range is in excess of 6 nautical miles (nm), more than twice the range of Soviet Tamir/MG-11 search light sonar originally proposed. SJD-1 sonar was jointly developed by 706th Research Institute, 726th & 461th Factories, and it is the first bow mounted sonar adopted by Chinese navy. SJD-1 is frequently confused with its successor SJD-2, more commonly referred as SJD-II, whose design started in 1970's, but was not completed until 1980's due to major redesign. SJD-1 sonar was installed on Luda class destroyers and subsequently upgraded to SJD-2 in the 1980's.

SJD-N

It was discovered that SJD-1 sonar cannot provide accurate locations of targets, and the error was too great to be adequate enough to provide fire solutions to onboard ASW weapons. Therefore, the design of Type 051D incorporated an additional high frequency (HF) active attack sonar designated as SJD-N (with Type 675 sonar transducer array) to provide fire solutions, and this attack sonar was subsequently fitted on all Luda class ships. SJD-N was subsequently upgraded to SJD-4 standards.

SJD-2

H/SJD-2 sonar, more commonly known as SJD-II, whose design started in 1970's, but was not completed until 1980's due to major redesign, is frequently confused with its successor SJD-1. SJD-2 is part of the effort (the other part being SJD-4) to improve the ASW capability of steam powered Chinese warships by incorporating Italian DE-1164 sonar technology. DE-1164 is consisted of 2 subsystems using the same electrical cabinet, DE-1160 hull mounted sonar (HMS, with a maximum range around 20 km) and DE-1163 variable depth sonar (VDS, with a maximum range in excess of 50 km). DE-1164 is the first sonar in Chinese service to have integrated the HMS & VDS. ED-1164 was installed on Type 051 destroyer for evaluation.

Trials revealed that the performance of DE-1164 sonar was disappointing, with a huge gap between the actual performance and what was specified in documents. However, this was not due to sonar, but the ship itself. Due to the inherent flaws of an old design, the ship is not an ideal ASW platform for advanced ASW system. The steam propulsion system proved to be the major hindrance preventing DE-1164 reaching its full potential. The noise and vibration generated by the steam boilers simply created too much interference with the sensitive sonar that it could only reach its full potential at very low speed. However, at such low speed, target would easily evade and escape Luda's attempt to attack. Test result led to two attempts to address the issue going in parallel: one of them was to upgrade SJD-1 with foreign technologies, and an addition of an attack sonar SJD-4. SJD-2 is thus an upgrade package for older steam-powered warships.

SJD-3

H/SJD-3 sonar is the Chinese development of Soviet Tamir-11(MG-11) search light sonar. SJD-3 hull mounted sonar differs from Soviet MG-11 in that instead of being fixed to the hull like the original MG-11, SJD-3 has a telescoping arm, so when not in use, the sonar is stored in the hull, and when deployed, the sonar is lowered into water several meter below the hull, thus increased detection range by avoiding baffles generated by the hull.

SJD-4

H/SJD-4 sonar resulted in the same experience of evaluation Italian DE-1164 sonar, which led to the development of SJD-2, the improvement of SJD-1. SJD-4, in turn, is the corresponding upgrade of SJD-N, utilizing the technologies of DE-1164.

SJD-5

H/SJD-5 is the Chinese development of Soviet Tamir/MG-11, with transistors replacing vacuum tubes in the original Soviet MG-11, thus reduced size and weight and increase reliability. SJD-5 sonar has several derivatives, including EH-5, with integrated circuits replacing transistors, which further developed into Echo Type 5, adopting LSIC technology. The latest member is SJD-5A, with VLSIC technology.

SJD-7

H/SJD-7 is the Chinese development of Italian DE-1164 sonar, with additional noise cancellation and vibration reduction measures so that it can be used on older steam powered warship, whose steam propulsion system generates much greater noise and vibration than diesel and gas turbine propulsion system.

SJD-9

H/SJD-9 is the Chinese development of French DUBV23/43 hull mounted/VDS sonar system, incorporating same additional noise cancellation and vibration reduction measures for installation on steam powered warships.

ESS-1/2

ESS-1 sonar and ESS-2 sonar are Chinese VDS and hull mounted sonars (HMS) developed from similar western counterparts. The origin of ESS-1 VDS and ESS-2 hull mounted sonar are subject to debate due to lack of official information, with some sources claim that ESS-2/1 are the Chinese version of DE-1160/1162 HMS/VDS, while others claim that it is the Chinese version of DUBV-23/43 HMS/VDS. Since the Italian and French sonars have similar performance (20 km for HMS, and 50 km for VDS), it is difficult to determine which is which, since official Chinese governmental sources only confirms the 20/50 km ranges for HMS/VDS. ESS-2 sonar has bearing accuracy of 1 degree and like its predecessors SJD-1/2, it has a cylindrical transducer.

SO-7H

SO-7H sonar is the Chinese version of French DUBA 25 sonar. As with SJD-7/9, SO-7H also incorporats additional vibration and noise reduction measures for upgrading older steam powered warships in Chinese navy.

SJG-206

H/SJG-206 is low frequency towed array sonar, the first towed sonar in China. Developed by China Shipbuilding Industry Corporation, it won 2nd place in National Science & Technology Advancement Award in 2003, and it equips many Chinese primary surface combatants.

TLAS-1

TLAS-1 sonar is the first Chinese towed array with a range of up to 45 km. This passive low frequency sonar is able to simultaneously tracking 5 targets, with a bearing accuracy of 4 degrees, and it shares the same operator console as ESS-2 HMS. This is a light towed system designed for smaller surface combatants.

SJG-208

H/SJG-208 is a towed sonar used by Chinese hydrographic and oceanographic survey ships, entered service in 1997, and its general designer is Mr. Li Qihu (李启虎), who is also the general designer of H/SQG-4 and H/SJG-206 sonars, and deputy general designer of H/SQG-207 sonar.

SQG-4

H/SQG-4 passive ranging sonar is also known as Type 204 sonar, it can be either used as part of H/SQZ-262 integrated sonar system, or as an independent system. Started in 1987, SQG-4 incorporated western technologies, namely French Thomson-CSF DUUX-5, and it deploys three arrays on each side of the submarine.

SQZ-262

H/SQZ-262 sonar is a fully digitized, integrated submarine sonar designed by Acoustic Research Institute of Chinese Academy of Sciences. Three versions of H/SQZ-262 was developed, with SQZ-262A replacing Type 105 sonar on Type 033 class submarine, SQZ-262B replacing Type 603 & 604 sonars on Han class and Xia class nuclear submarine, and SQZ-262C installed on Type 035G Ming class submarine.

SQG-207

H/SQG-207 flank array is a flank sonar newly developed by 715th Research Institute, first equipped Chinese nuclear submarine, and then conventional submarines during refits, it is the first flank sonar in China.

Synthetic Aperture Sonar (SAS)

Chinese synthetic aperture sonar (CSAS) is a SAS developed by a team lead by Acoustic Research Institute of Chinese Academy of Sciences, partnered with the 715th Research Institute of China Shipbuilding Industry Corporation. The program first begun in Jul 1997 one of the 863 Programs, and the general designer of CSAS was Chinese academician of sciences Mr. Li Qihu (李启虎), also the general designer of H/SQZ-262 sonar. In comparison to imported SHADOWS SAS developed by French firm IXBLUE, CSAS has higher resolutions: the model of CSAS that utilizes both the medium and low frequencies has a resolution of 0.1 meter, as opposed to 0.15 meter of SHADOWS SAS. The model of CSAS that utilizes high frequency has a highest resolution to 5 cm x 3.75 cm.

SAS for AUV

China has also developed a miniature SAS for autonomous underwater vehicles(AUVs). Developed by the Information and Communication Engineering Research Institute of Zhejiang University as part of one of the Project 985 programs, the general designer of Chinese SAS for AUV is Professor Mr. Xu Wen (徐文) of Zhejiang University.

XT02WR01

XT02WR01 sonar is a diver detection sonar (DDS) developed by (Beijng) New Source Yongtai Electro-optics Science and Technologies Development Co. Ltd. (北京新源永泰光电科技发展有限责任公司) in Beijing. The system can cover up to 150 hectares of area, with an effective range against a diver at 400 to 700 meters (w/ errors of 0.5 meter in distance, 15 meter in bearing). The size of the system (wet end) is very compact, weight less than 50 kg, with a diameter of 0.5 meter and a height of 0.65 meter. The wet end only need 200W of power, same as an ordinary household television, with 220V power source. The wet end of XT02WR01 sonar can be deployed in a depth up to 40 meter deep and can operate in sea state 4 continuously for 3 years, and the entire system can be fully autonomous, operating without any human intervention. The dry end of XT02WR01 sonar system has numerous options based on customer demands, linked to the wet end via waterproof fiber-optics cables.

Tronka

Tronka sonar is a DDS jointly developed by Ukraine and China. The systems weigh 415 kg (115 kg for wet end, 300 for dry end), and can be deployed in a depth up to 20 meter. The effective range is 0.5 km, with an accuracy of 1.5% in range, 2 degrees in azimuth. The height of the wet end is 1.5 meter, and the service life of the system is 10 years.

Underwater Security System

Underwater Security System (USS) is an indigenous Chinese nonlethal diver repellant system developed domestically by a joint team of Institute of Acoustics (中科院声学所) of Chinese Academy of Sciences (CAS), Shanghai Ship & Shipping Research Institute (上海船舶运输科学研究所) of China Shipping Group, and Xi’an (Research) Institute of Optics and Precision Mechanics (西安光学精密机械研究所) of CAS. The general designer of USS is Mr.Xu Feng (许枫, Jun 1969 -). The detection subsystem of USS is consisted of both the stationary and mobile sonars. USS has been first deployed in 2008 Olympic games in Chinese port cities hosting water sports, and has since been adopted subsequently by Chinese law enforcement, para-military and military establishments.

Harbor Underwater Frogmen Detection System

Harbor Underwater Frogmen Detection System (HUFDS) is a DDS system actively marketed in China by its developer, Beijing Time Frequency Technology Co., Ltd (北京泰富坤科技有限公司) in Beijing.

SQX-1

H/SQX-1 sonar is a communication sonar for underwater communications, with the transducer reportedly designed as Type 063.

SQC-1

H/SQC-1 sonar (with transducer designated as Type 604) is a passive sonar installed on first generation Chinese nuclear submarines when they were first launched, and it is no longer in service, replaced by H/SQZ-262B.

SQZ-3

H/SQZ-3 sonar (with transducer designated as Type 603) is a active sonar installed on first generation Chinese nuclear submarines when they were first launched, and it is no longer in service, replaced by H/SQZ-262B.

SQZ-D

H/SQZ-D sonar (with transducer designated as Type 105) is a sonar for older generations of diesel submarines and it is no longer in service, being repalaced by H/SQZ-262A. The performance of SQZ is almost identical to the original Soviet sonar it was developed from, except the sector of scan, which is increased by 15 degrees. The volume and weight is also decreased considerably when the original vacuum tubes of the original Soviet sonar (Tamir 5L, NATO reporting name: Perch Gill) was replaced by transistors and integrated circuits.

SQC-1

H/SQC-1 reconnaissance sonar is no longer in service when its functions can be performed as part of that of H/SQZ-262 sonar.

Type 801

Type 801 sonar is a Chinese development of Soviet MARS-24 sonar for diesel submarines. Type 801 provide azimuth of targets and it is a passive system. The only difference between Type 801 sonar and its predecessor MARS-24 sonar is that there are 24 transducer elements for Type 801 as opposed to 12 in the original MARS 24, so the Chinese sonar had better accuracy.

SQG-2

H/SQG-2 sonar is the first domestically developed indigenous Chinese passive ranging sonar, developed to complement Type 801 passive sonar, which could only provide azimuth, but not ranging. SQG-2 is a ranging only sonar that is no longer in service, being replaced by more advanced development.

SQZ-1

H/SQZ-1 sonar is an integrated sonar system that integrates Type 801, SQC-1, SQG-2 and SQZ-D sonars so the overall combat effectiveness is improved, in comparison to the old practice of each sonar working separately and info obtained from each individual system must be manually interpreted to form a overall picture. SQZ-1 is no longer in service and has been replaced by SQZ-262 sonar.