These are indeed exciting times. Seven indigenous weapon systems tested in a time-run of just ten weeks; Shaurya hypersonic missile, BrahMos Extended Range (ER) missile, Prithvi nuclear capable missile, Hypersonic Technology Demonstration Vehicle (HSTDV), Supersonic Missile Assisted Release Torpedo (SMART) weapon system, Nirbhay sub-sonic cruise missile and Rudram -1 Anti-Radiation Missile (ARM). The last mentioned is a real capability-enhancer which not only stands at par with its peers in the world, but also pips them in several operational parameters¹.

Why is ARM such a capability-enhancer for the air warriors? What makes Rudram 1 a cut above the rest? Where do we go from here? These are some of the questions which this article attempts to answer.

Why ARM?

There was an era long back into history when the air threat from the adversary used to be prosecuted by the valiant gunner standing up in his propeller-driven aircraft and trying to train his machine gun on the ground targets through hit and trial.

This is the era of 21st Century air combat. The same is prosecuted by 4th and 5th generation aircrafts. Flying on the enabling wings of technology, these all-weather, all-terrain machines can deliver precision strikes at long stand-off ranges while remaining largely undetected by defenders’ sensors; thanks to their growing stealth muscle. The aircrafts are joined by other aerial threat vehicles such as attack helicopters, capable of preying on their targets while remaining elusive by flying in the nap-of-the-earth, needle-sharp cruise missiles, a whole world of unmanned platforms giving a run for their money to their manned brethren when it comes to diversity in roles, lethality, endurance and more and the deadly ARMs.

To counter such a formidable threat, the air defences based out of aircrafts, surface-to-air missiles (SAMs), guns, shore and fleet-based weapons and more, are integrated on land sea and air into one system, normally referred to as the Integrated Air Defence System or IADS for short. The IADS thus represents the cumulative air defence capability of the nation to take on the adversary’s air threat. This air threat is not only multi-platform as stated above, but also multi-domain manifesting on land, sea and air at the same time.

The fundamental requirement to defeat this threat is to detect it as early as possible and subject it to effective and seamless fire that must shift successively from weapon-to-weapon as the threat draws in and must continue relentlessly, till either the threat is destroyed or the mission is abandoned.

The system which makes it happen by binding the air defences at land, sea and air into one cumulative whole is called the Air Defence Control and Reporting System or ADCRS for short. ADCRS ensures multiple functions to drive the IADS. These include, carrying out surveillance of the airspace, identification of the hostile threat into friend and foe, prioritisation of the threat based on comparative lethality and timing of impact, selection of most suitable weapon to take on the threat, designation of the targets to the selected system, shifting of fire successively and seamlessly from weapon-to-weapon and the minute-to-minute control of the air defence battle. All this and more in a matter of few fleeting minutes! ‘Few minutes’- that is where lies the criticality.

Suffice to say that if ADCRS is gone, air defence weapons will be deprived of their ‘eyes and ears’ and can then be destroyed as ‘sitting ducks’. This method of silencing the air defence weapons is referred to as ‘suppression of enemy air defences’ or SEAD for short. ARMs are the weapons for carrying out SEAD. How?

ADCRS is based on three verticals, namely, sensors, communication systems and C&R structures.

Sensors refer to all types of radars which detect aerial threat and direct the weapons on them. These may include the early warning radars for pure surveillance, tactical control radars for surveillance and designation of selected targets to weapon systems, missile guidance radars to guide SAMs to the targets and fire control radars to control the fire of guns.

Communication systems based on radio, line, electro optics or configured on the satellite communications ensure the flow of information over the IADS in execution of the multiple functions of ADCRS as enumerated above.

C&R structures have been mentioned in their generic sense to mean an entire network of ADCRS nodes that represent the battle management and control link from the highest (national level) to the weapon platforms. It is on this lifeline that the entire air defence battle flows and is strictly controlled on a minute-to-minute basis. ADCRS is CRITICAL not only to take on the threat by inflicting on it, successive and seamless fire, but also, and more importantly, it is a must to avoid fratricide. ‘Blue-on-blue’ remains the most cardinal sin of the air defence warrior.

In the above scenario the ARM strikes its lethal blow in this manner:-

1. It has a pre-formatted ‘threat library’ which stores the digital signatures of the adversary’s sensors and communication systems (by way of frequencies, band width, peak power, pulse repetition frequencies, beam patterns and more). It may also store the known location details of the said sensors.
2. Building up the threat library is a very painstaking 24x7 activity during the peacetime. It is called building up the electronic order of battle (ORBAT) by piecing together electronic intelligence (ELINT) data over a period of time.
3. Once the aircraft carrying an ARM takes off for a kill, the real-time inputs as picked up by its sensors are checked out with the data base in the threat library in order to identify hostile emitters. There may be multiple sources of locating threat sensors, like the radar warning receivers (RWRs) on-board the aircrafts that warn the pilot if the aircraft gets illuminated by a defenders’ sensor etc.
4. The ARM upon location of its target may achieve a lock-on before launch or do so after the launch (these techniques are not explained further).
5. For doing the above, the ARM may have two types of seekers. Active seekers which emit electromagnetic energy or passive seekers which achieve a lock on based on the emissions from the adversary’s radars or communication systems.
6. The navigation to the target is through GPS/INS using the satellite.
7. Modern ARMs have a feature in which, even if the sensor switches off, post the initial lock-on by the missile, the ARM can continue its flight to the assessed target location based on re-generated target parameters.
8. As stated, once the backbone of the ADCRS is broken by destroying the sensors, communication systems or C&R structures, the binding glue that held the IADS together gets destroyed. With that the capability of the system to wage a coordinated air defence battle in the manner explained above, also gets destroyed. The weapons now become deaf and blind and can be taken out at will in a SEAD operation.

So much on the lethality of ARMs

Technical Muscle of Rudram-1

The technical muscle of Rudram-1 can be assessed when seen in comparison with the contemporary ARMs in the world. For this comparison, the ARMs which have been taken into consideration are the US AGM 88E (also referred to as the High Speed ARM or HARM), its advanced version called the Advanced Anti-Radiation Guided Missile or AARGM and AARGM (ER), Brazilian MAR 1 and the Russian series of ARMs in the Kh series (22, 25 MP, 31 P) etc²³⁴⁵⁶⁷.

Following points are stated in comparative analysis:-

1. The first issue relates to vintage. Rudram programme was sanctioned way back in December 2012 at a cost of 317.2 Cr and had a PDC of 2017. The Captive Flight Trials (CFTs) started sometime in May 2016. It was only by January 2019 when the first Rudram (referred to as NGARM or new generation ARM) was launched from SU 30 MKI. The vintage of the weapon is therefore of the period 2016-2020; the block period is indicative of the continuous development and refinement of the NGARM. Some ‘experience points’ from Shaurya missile and the HSTDV also got included in this development process.

This compares favourably with the vintage of the other ARMs under consideration. AGM 88E is of 1983 vintage, AARGM- 2010, MAR 1- 2012, KH 31 series 1988 and counting. This vintage differential shows up as ‘technology differential’ as will be seen later.

2. The second point relates to the operational range of the ARM. Using the dual-pulsed rocket motor technology (Shaurya), it has been possible to achieve a range of 100-250 kms. This again compares favourably with AGM 88E - 150 km, MAR 1 -60-100 km and KH 31 - 60-110 km.

Greater range means a capability to take on its targets while being fired from greater and greater distance away from adversary’ s defences, thus ensuring enhanced safety to own platforms.

3. The next capability-defining parameter is missile speed. The greater will be the speed of the ARM, the lesser will be the time available to the defender to take evasive actions and smaller will the time the missile will be exposed to adversary’s electronic countermeasures.

Rudram achieves a speed of 0.6 to 2 Mach. This is better than 1.84 Mach of AGM 88E. The Russian ARMs however fare better in this parameter with speeds ranging from 2.7 -3.1 Mach.

4. Another important parameter is the seeker. Seeker is the heart of the missile as the capability of the weapon to acquire and home on to its target is the function of the seeker. Higher is the sensitivity of the seeker, greater will be the capability of the missile to seek and home on to the targets. Seekers can be active or passive. The earlier vintage missiles like AGM 88E or the MAR 1 had only passive seekers.

Rudram has both an active, as well as, a passive seeker. Its active seeker is a millimetre wave seeker. Its passive seeker is a wide band seeker. The band of this seeker extends from D to J which covers the radar bands L , X, C , S and Ku.

The active and the passive seeker together represent a very large range of wavelength and frequencies which this missile will be able to acquire and home on to. In operational terms, it means that the missile has a capability to kill a large variety of radars be it early warning, tactical control, missile guidance or fire control missile guidance etc. This is so since each of these radars class is optimised for its primary role in a typical wavelength-frequency band.

5. Another capability worthy of noting is the capability of the missile to continue homing on to the target even if the target (emitter) has switched off, provided the target signature is available in the threat library of the missile and the initial lock on was achieved. This niche feature is only available in later generation ARMs like AARGM (ER) etc.

On the flip side, for all the parameters it can boast off, Rudram has a greater length and weight features as compared to other missiles (Rudram length weight figures - 5.5 m, 600 kg. AGM 88E - 4.1m, 355 kg, AARGM -3.9 m. 350 kg, MAR 1 - 3.9 m, 266 kg and KH 31- 4.7 m, 610 kg).
Higher physical dimensions mean a greater radar-cross section (RCS) and the greater capability of the enemy sensors to detect the missile at farther ranges. While this disadvantage may get partially offset given the higher speed and higher operational range of the missile, it is a disadvantage all the same in comparative terms.

Be that as it may, taking all the features stated in the above analysis, it can be stated that Rudram is indeed a formidable weapon and it does stands tall with its peers and contemporaries in the field.

Some Reflections

1. As stated in the beginning, these are exciting times. Seven indigenous weapon systems, each featuring some niche technology or the other getting tested in a period of mere 10 weeks is indeed good news for ‘Atmanirbhar Bharat’. The challenge starts after the good news.
2. And the challenge is actually well known. It is the ‘time and cost overrun’ which unfortunately has become the abiding signature of our public sector in many cases. DRDO is only a development agency; the production of Rudram is jointly shared between Bharat Electronics Ltd (BEL) and Bharat Dynamics Ltd (BDL). Both have been designated as production agencies (PAs). Following points are relevant here:-
1. It has to be ensured by both the PAs that the missile is productionised in a strict timeframe of say 2-3 years. It must not linger on the shop floors for 6-8 years.
2. The time and cost overruns not only are costly to the exchequer, it keeps the forces deprived of the systems and capabilities that already stand realised. Sometimes the ominous time delays result in the technologies becoming obsolescent before the weapon even reaches the hands of the user (sic). This must be avoided at all cost.
3. Another important point relates to the need for an attitudinal change in the minds of all the stakeholders. In that the system must recognise the ‘new normal’ and the new normal is that the defence private sector in India HAS ARRIVED. What does that mean? Probably the following:-
1. The private sector is now capable like never before, to take on the manufacture of armaments and ammunitions covering a wide-spectrum of capabilities and technologies.
2. In that spirit, notwithstanding the fact that BEL and BDL are the main PAs for Rudram, maximum offloading must be done to the private sector in order to diversify the manufacturing base. Only then it will be possible to meet the timeline of 2-3 years for successful production.
4. As per the plan, besides SU 30MKI which is the primary test platform for Rudram, the missile is to get integrated with other aircrafts as well. These include Mirage 2000, Jaguar and Tejas Mk II (MWP).

These are very long-lead activities requiring a huge amount of modification, integration, testing, certifications and more. It is hoped that these are already underway; if not as yet, it must commence earliest.

5. What is the road ahead for Rudram? It is reported that there are plans for software improvements in the future. It is hoped the same will kick in as the time rolls.

Be that as it may, it is indeed a matter of pride to place on record that a niche operational capability stands developed successfully which is certainly a step forward on the road to self-reliance. The caption of this article thus finds its relevance.

Endnotes

1. “India successfully test fires anti-radiation missile Rudram 1 to destroy enemy radars,” at www.timesofindia.indiatimes.com. Accessed on 05 Nov 2020.
2. “AGM 88E Harm,” at www.deagel.com.Accessed on 06 Nov 2020.
3. ”AGM 88E AARGM,” at www.defpost.com.Accessed on 06 Nov 2020.
4. “AAGM-ER- a joint anti-radiation defence,” at www.defence24.com. Accessed on 06 Nov 2020.
5. “MAR -1 ARM Missile,” at www.creavorite.com. Accessed on 08 Nov 2020.
6. “Kh-22,”at www.wiki2.org. Accessed on 08 Nov 2020.
7. “Russia’s TMC unveils a new version of Kh 31 ARM,” at www.reserachgate.net. Accessed on 11 Nov 2020.

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