Indian Defence Review

Developments in the LRSR

The initial version of the LRSR associated with S-300 was 36D6 (NATO ‘TIN SHIELD’). It was a 2-D surveillance radar operating in the E/F band (2-3 Ghz/ 3-4 Ghz) with a range of 180 to 360-km and a capability to simultaneously detect 120 targets. 36D6 was optimised for medium/high altitude detection. However during the early eighties and beyond, when the avionics onboard the aerial threat vehicles allowed for a low and level prosecution of the attack, neatly avoiding radar detection by the type of surveillance radars signified by 36D6, a need was felt to associate with the system, low attitude detection capability.

Keeping in mind the above, another LRSR optimised for low altitude detection was associated with the system (versions S-300 P and S-300 PS/PM). This radar was 76N6 (NATO ‘CLAM SHELL’). 76N6 was an I band (8-10 Ghz) radar and with a capability to detect 300 targets (catering for multiple saturation raids on large sized VAs). Some range compromise was obvious at low altitude due to ground attenuation of radar energy (range 120 km).

A combination of Medium/High with Low altitude with respective operational ranges pegged at 300 km and 120 km actually shows the canny understanding of the air attack pattern by the weapon designers in that, while the ‘eyes and ears’ of the system went really long up to 300 to 360 km for a possible medium/high altitude detection, the low and level detection anchored was not required to stretch beyond 120 km as that would be about the maximum range at which a potential low and level raid will actually start to descend for aligning with the intended attack profile.

The next development in the LRSR domain was when 36D6 was replaced by another LRSR is called 64N6 (NATO BIG BIRD).This radar was designed to operate in still lower E/F band was optimised for detection of Ballistic Missile class targets up to 1,000 km away travelling at up to 10,000 km/hr.

The shift towards the lower bands was again a deliberate and smart move by the weapon designer as lower band radars were found to be more efficient in the detection of Very Low Observable (VLO) or stealth threat.

The above gain had to be balanced against the disadvantages of large antennas and unwieldy designs of these radars making them slow to move and deploy and easy targets for ARM attacks. Experience in field however showed that even with the above disadvantages, VLO capable radars which were a greater necessity for the emerging stealth threat, could operate safely under the overall protection umbrella provided by the mainstay weapon system.

The weapon designers invested a lot of resources in the initial detection of the incoming threat. In that, to further augment the detection capability of 36D6 (medium and high altitude) radar and the low altitude detection of 64N6, another all-altitude detection radar 96L6E (NATO ‘CHEESE BORAD’) was also made a part of the weapon system (range of 300 km and a max capability to simultaneously detect 300 targets).

The latest development in the weapon system in the field of LRSRs is the radar 91N6E (with S-400). This radar is an upgraded version of its predecessor 64N6E. It is a Panoramic 3D All Altitude Radar Detection System with a maximum range of 600 km and a max target track capability of 300 targets. Ranges actually vary based on the Radar Cross Section (RCS) of the target. This radar is a fully digitised adoption of the earlier 64N6E system. It is a 2700-element phased array radar with latest ECCM features such as the frequency agility, suppression of side lobe jammers and a capability to accurately measure the location of jamming sources. The reflective phased array technology allows the radar to search two opposite 90 degree sectors simultaneously greatly improving its detection probability. The radar is especially optimised for Ballistic Missile targets and has a capability to detect stealth targets.

Developments in the MFTR

The initial versions of the weapons system started with 30 N6 (NATO FLAP LID) MFTR. It is an I/J Band radar which is a typical band for fire control and missile guidance systems. Over a period of time, the MFTR kept on improving in its capability of simultaneously tracking and engaging targets. This capability enhancement is a direct effect of the signature feature of the contemporary threat which demands that multiple threats be simultaneously tracked, and based on threat priority, engaged alongside, as well. These radars had ranges of 200 km which was considered adequate for an MFTR getting its target designation from LRSRs.

As the threat versatility grew, aerial targets started to operate in a wider band spectrum. A need was thus felt for the MFTR to embrace broader spectrum detectability. Also, there was felt a requirement of more compact system especially for the V series of the weapon system. To address this requirement, a Multi-band MFTR 9S32-1 (NATO GRILL PAN) was designed. The compactness of the system had a range penalty which reduced to 140 to 150 km.

Development in Missiles

The unique signature of the S-300 family as regards its missiles are concerned has been its capability of featuring multiple missiles with varying ranges all fireable from the same weapon platform with nil/minimal changes on action-stations.

As to the guidance system, the initial versions of the missiles (5V55K, 5V55R) used the basic Command guidance where the MFTR tracking both the missile, as well as, the target, gives commands to the missiles to home on to the target. These missiles had a range in the bracket of 50 to 75 km.

As the technology advanced, the newer missiles (5V55R, 5V55KD, 5V55U, 9M82, 9M83, 9M83ME) switched to Semi Active Radar Homing (SARH) Guidance, wherein, the missile guides itself to the target by homing on to the signal of the illuminating radar reflected off the target. The range of such missiles increased (150 km approximately) since missiles being semi-active, need not carry radar transmitter electronics on board except for a small mono-pulse radar for terminal/end game guidance.

Then came the missiles having Track-Via-Missile (TVM) guidance (48N6, 48N6 E2). In this, though the missile still receives the radar energy from illuminating radar reflected off the target, it does not use this signal to home on to the target as in the case of SARH missiles; instead, it relays the signal back to the ground station which passes guidance command to the missiles to home on to the target. The biggest advantage of TVM is that the missile remains passive and is not painted on the aircraft’s radar. Due to this, when a TVM system is engaging a threat, say an aircraft, the pilot will know that a SAM radar is illuminating it but whether it is being engaged by a missile, it will not know. TVM missiles were particularly found useful in tackling low level threats.

And finally, the missiles of the S-300 family graduated to the Active Radar Homing (9M96E1, 9M96E2, 40 N6) as in the case of S-400 system. These missiles carry an active radar trans-receiver capable of finding and tracking its target on its own steam. The missiles being closer to targets (than the ground radar) produce highly accurate tracking with much better resistance to ECM. These missiles therefore have very high kill probabilities (>90 per cent) and a fire-and forget weapon effect achieving high ranges.

Out of the above missiles, the three specific missiles onboard, the S-400 have the following special features:

• The 40 N6 is an extremely long range missile (400 km). Because of being independent, it can engage targets out of radar sight of the ground radars. The missile features both an active, as well as, a semi active homing seeker thus combining the advantages of both systems. Also, the flight profile of this missile (apogees in excess of 40 km) enables the missile to convert potential energy into kinetic energy during the terminal phase. This makes the missile accelerate as it dives on the target permitting higher G capabilities as compared to flatter cruise profile. The missile is optimised for the ABM role.
• The 48 N6 is a long range missile that has a number of variations covering different range brackets. 48 N6 DM (48 N6E3) covers the longest range of 250 km. It is an SARH missile flying at 17,000 km/h or Mach 14 and is capable of handling target speeds up to 4,800 m/s. 48 N6 E2 is a TVM missile (optimised for low level attacks). It has little less range of 200 km. Its corresponding features are 10,000 km/h, Mach 8.2 and 2800 m/s. The original 48 N6, the base version is also a TVM missile with a range of 150 km.
• The third type of missile with the system is the 9M96 Series. Two versions are held 9M96E1 and 9M96E2. Both are active radar homing missiles covering close-in threats. 9M96E1 has a range of 40 km while 9M96E2 has a range of 120 km.

Other Systems

The BMC2 system (30 K6E) provides a full automation of Control and Reporting (C&R) system for the entire conduct of the Air Defence battle. The automated battle functions include the Coordination of surveillance by multiple sensors through Multi Sensor Fusion, generation of Recognised Air Situation Picture (RASP), Prioritisation of the incoming threat, Target Selection, Missile Assignment and the minute-to-minute control of the air defence engagement.

The vertical launch operation of missiles negates the need of Lock On Before Launch (LOBL) and can quickly respond to the threat developing from any direction. This makes the system highly responsive.

The deployment time of a typical Fire Unit has seen a compression in time from over an hour in the initial S 300 systems to 10 to 15 minutes in the current version for a single fire unit.

Quantum

Normally a battalion (Fire Unit or FU) of S-400 has eight launchers each with four missiles (32 Missiles). Besides this, each FU it will have its own contingent of LRSR (either a Panoramic Detection System like 64N6E of a pair of medium/high altitude LRSR (36D6) with a low altitude detection system (76N6) , one or two MFTRs (30N6 or its variants or 9S32-1), the BMC2 system (30K6E) and associated support structures, vehicles and maintenance gear. The missiles could be in a combination of 40 N6, 48N6 and its variant (48N6E2) or the shorter range 9M96E1/9M96E2.

Five such systems will have a multiplication factor of five to the above basic constituents cutting out duplicates where possible.

The quantum of missiles will actually be distributed over the first line, second line and War Wastage Reserves (WWR) and training aggregates. One open source quotes a figure of 6,000 missiles.

Impact of Induction

Will the proposed induction be a “game changer” as claimed by many? Some thoughts:

• A weapons system of such range and altitude capability (20 to 400 km and low and level to 56 km) is a totally way up induction from the capability that is currently possessed.
• As a part of the overall layered and tiered defences anchored on the theatre grid, the system will integrate seamlessly with the existing lot of GBADWS. This feature of backward and downslide integration has been specifically flagged by the OEM of the system. It will imply the following:

– The LRSR resources of the system will be able to provide long range and ultra long range early warning to the integrated family of GBADWS tied to S-400 in layered and tiered defence.

– The MFTR of S-400 will not only be able to provide BMC2 support to S-400 Fire Units but will also be able to thread other shorter range and altitude systems (MRSAM, SRSAM and VSHORAD) fire units in providing continuous successive punishment to the incoming threat.

– While the existing GBAD weapon inventory is seriously limited in its overall range and reach capability (exact figures omitted), the gaps will gradually get filled up as the modern GBAD weapon systems get inducted over time.

– Once the above is realised in times to come, the entire range-altitude bracket will stand addressed (terminal GBADWS 2 to 3.5 km, VSHORADS – 3 to 7/8 km, SRSAMS/QRSAMs- 2/3 to 20/30 km, MRSAM- 5 to 50/70 km, LRSAM >100 km) and the S-400 (20 to 400 km).

– While not talking about the quantum adequacy of GBADWs where huge voids remain (percentages not covered), the type of capability which the S-400 brings along makes every single aerial threat vehicle in our immediate and extended neighbourhood addressable be it strategic bombers of the type H5/H6/H6K, or the front line strike aircrafts like Q5,J8,J11,J16, JF17, SU27,SU30, F16, Mirage or stealthy targets like J20,J31, PAK FA or the FGFA targets like FC31 and more (lower end threat not mentioned).

– The S400 being an anti-missile system will complement the indigenous capability as contained in Programme AD. In that the FUs which are normally deployed for protecting the city-centres/seats of power/industrial and financial hubs could be deployed complementing each other. It must, however, be appreciated that given a huge quantum of VAs/VPs that need to be protected, the limited quantities of Programme AD FUs combined with FUs of S-400 will still leave quantum voids.

–  With the BMD capability as jointly achieved above, the SSM threat from our immediate and extended neighbourhood (from the HATF range up to and including Ghauri class and the DF series known to be in Tibet Autonomous Region) will become addressable, “capability wise”.

On the Flipside

While all looks very hunky-dory on one side, the following realities also need to be understood:

• The procurements of this magnitude get spread over many years (three to five on a modest count).

• Experience has it that from initial negotiation to the Contract itself, following the DPP route, is anything up to one to two years on a most promising/optimistic note. This is to be followed up with phased deliveries to be built up over another three to four years. Alongside this, will be the huge requirements of spares, training aggregates and simulators besides initial training of crews and maintenance staff. It is likely to be anything from three to four years before the capability is realised unless some shortcuts/overlaps are approved and taken.

• Mention has already been made of the quantum inadequacy for which the figures cannot be discussed.

Now, it is up to the reader to decide whether the claims of the proposed induction of the S-400 Air Defence System will be a “Game Changer”.