Iran’s Bavar-373: A Profile
A wholly indigenous system
Despite Russia finally delivering the S-300PMU-2 to Iran in December 2016, the Bavar-373 is commonly conflated with being simply a copy of the S-300. Iran had displayed numerous Bavar subsystems before the S-300PMU-2 delivery in December 2016, and even made a partial unveiling of numerous radars, missiles, and a restricted view of the launch cells in August 2016 – also on Defence Industry Day. Although Iran is suspected to have acquired an S-300PT system from Belarus, that is a 1980s-vintage system, with dated radars and 5V55K/R missiles up to a maximum range of just 90 km. While it is possible that Iran learnt some concepts and technologies by studying this system, any real relation between the S-300PT and the Bavar-373 is out of the question, not least because the Bavar-373 is far more capable, being closer to the S-300PMU-2 and S-400 in terms of performance and sophistication.
Not only does Bavar-373 sport AESA radars and a 200 km range missile in the form of Sayyad-4, but very clearly all these key subsystems look physically different and distinct from their foreign counterparts. Bavar-373 also has indigenous vehicles, and the missiles are launched directly (‘hot launch’) from square launch cells, rather than the gas ejection (‘cold launch’) system of the S-300’s circular missile tubes.
To help clear up any confusion I made this handy comparison chart.
|Comparison showing Bavar-373 and S-300 equivalent subsystems side-by-side: (Top to Bottom) TELs, Engagement Radars, Acquisition Radars, Battle Management Radars|
While the Bavar-373 is an Iranian system, it certainly does take some conceptual nods from the S-300.
Bavar-373 is a large, top-of-the-line system, and therefore not as easily hidden as the Sevome Khordad system that shot down an American RQ-4 UAV in June. However, it is still highly mobile, with the large 10×10 Zoljanah acting as the TEL vehicle, and most radars and command and control (C2) equipment being mounted on the Zafar 8×8 vehicle. Both trucks are clearly off-road capable. This is an important capability as although Iran has a large road network, it means Bavar-373 can be deployed almost anywhere. The only ‘semi-mobile’ component of Bavar-373 is the large Meraj-4, which is a battle-management radar with a similar role to that of the 64N6E/91N6E ‘Big Bird’ radar. That is mounted on a semi-trailer pulled by a civilian type tractor truck. This is not so much of an issue though, with its long range allowing it to sit in a deeper position and therefore have greater security compared to the ‘front-line’ radars.
Meraj-4 Battle Management Radar
In reality the Meraj-4 is not strictly an integral part of Bavar-373. But it is closely related to the system and has appeared throughout Bavar-373’s development, including alongside it in Bavar’s partial unveiling in 2016. It is a higher tier IADS asset, and its job is to control large swathes of airspace providing information to systems in its vicinity. It is a large array size, S-band linear AESA that can reportedly track up to 100 targets simultaneously. Along with this come advanced features that are detailed on a website called kowsartrading, which seems to be the successor to the short lived Iran Electronic Industries website. With ECCM capabilities including “Burn Through, SLB and SLC, Frequency Hopping, PRF Jitter, PRF Staggering, JATS, Pulse Compression, MTI, CFAR, Clutter Map, Low SLL Antenna,” Meraj-4 should be a resilient radar.
|Meraj-4 in full view in 2016|
|The latest iteration of Meraj-4, seen here in a new folded configuration, was present at the Army Parade in April 2019|
|Spec sheet for the Meraj-4 radar|
Sayyad-4 Surface-to-Air Missile
The Sayyad-4 was first seen in 2014 in TV footage that displayed even some of the early iterations of Bavar-373’s radar systems. At this time, it appeared as a very large white missile with باور-۳۷۳ (Bavar-373) just about visible on the body of the missile. It appeared alongside another new missile, the red Sayyad-3.
|Sayyad-4 missile (right) in 2014|
Sayyad-4 has a 200 km range, and maximum engagement altitude of 27 km. It is vertically launched from the Zoljanah TEL. It likely uses a form of Semi-Active Radar Homing, probably TVM (Track-Via-Missile) or SAGG (Seeker-Aided Ground Guidance). While ARH (Active Radar Homing) would have been an easier solution for a long range SAM, it would have been susceptible to jamming, and not been as effective against stealth targets (this is explained later in this blog post).
One of the more mainstream benefits of SAGG is that because guidance calculations can be calculated by both the missile and the ground radar, there is an added layer of redundancy that makes it more resistant to jamming. SAGG also tends to not give a missile launch warning to RWRs (Radar Warning Receivers), only letting them on that their aircraft is being illuminated. The inherent LPI (Low Probability of Intercept) characteristics of AESA radars enhances this advantage.
As of yet, it is unclear whether Bavar-373 has TVC (Thrust Vectoring Control) as in the S-300’s 48N6 missile. It is unlikely to have this feature, as its ABM role is only secondary, and unlike the Russian system there is no requirement for Bavar-373 to engage low-flying cruise missiles at short range, which is part of the reason why the S-300 has a cold launch system and why TVC activates immediately after ejection to orient the 48N6 to fire in the right direction. Iran already has shorter range systems without VLS, like the Sayyad-2 and Sayyad-3 missiles, that are more suited to low-altitude/short-range interception.
|The Sayyad-4 missile (serial no. SD4AM M4A) at Bavar’s official unveiling in August 2019|
|Comparison of Sayyad-4 (top) and 48N6 (bottom) missiles. The Sayyad-4 has a completely different fin assembly, no confirmed TVC, and slightly more tapered nose.|
|Sayyad-4 making a sharp turn after launch|
Unnamed X-band Radar
One distinctive feature of this radar are the 4 additional arrays on the sides of the main array. It is unclear what purpose these have – they may be SLC (Side Lobe Cancelling) arrays, sub-arrays, or even data-link channels. If they are sub-arrays, then it is possible that the small main array of this X-band radar is deceiving. The inward angle of the sub-arrays suggests they could be creating an effect called constructive wave interference to produce higher gain and effective higher range. This allows the radar to remain compact and have relatively low power levels compared to brute force PESA solutions like the 30N6 Tomb Stone/92N6 Grave Stone. The AESA TRMs of this radar allow electronic beam steering to align the radar waves to make use of this effect correctly. The radar being an AESA also helps Iran push down the power requirements for the radar. Iran’s defence minister said in an interview that this radar has 10,000 “elements” (TRMs).
|Bavar’s X-band radar array, with main components highlighted. main array in Red, possible sub-arrays in Yellow, and IFF array in Blue.|
Unnamed S-band Radar
Against normal non-VLO targets, the S-band radar works how any acquisition radar works. It may not even be needed if the Meraj-4 is free to support the battery from the back line. However, its smaller size and therefore superior mobility on the Zafar 8×8 truck makes it a valuable battery-level asset on the front line and earns it a place in the Bavar-373 system. This S-band component makes Bavar-373 a dual-band system (similar to the latest versions of the Aegis Combat System). This has positive implications for its ability to be used against stealth aircraft.
Very prominent is a large IFF-antenna on top of the radar array, a display of the radar’s high requirement for tracking range and numbers. It is a similar case on the X-band radar.
|Bavar’s S-band radar array. Red area is the main array, blue area is the IFF array.|
Command and Control (C2) Vehicle
The C2 cabin sits atop a 6×6 truck that seems slightly larger than the usual 6x6s Iran uses for its Talash and 15 Khordad TELs and radar vehicles. While we have not got a view of the inside of the cabin, the use of a dedicated C2 vehicle (in contrast with medium-range systems like 15 Khordad that have the C2 cabin with the radar cabin) is an indication of the sophistication of this part of Bavar-373. Curiously, there are no visible antennas on the C2 vehicle for long-range communication – this is not surprising however, as Iran (unlike Russia) deploys battery vehicles at one site rather than scattered over a wide area.
|Foreground: Bavar’s C2 vehicle|
|Bavar-373 command structure|
Zoljanah 10×10 TEL
Zoljanah was first seen in September 2012, sporting an unusual angular cab. In 2014 the current design was shown, with a much more sober cab design that was practically ahead of the front axle, instead of on top of it as the first iteration. This was possible to create more room for extra equipment behind the cab, seemingly for power generators and storage. Even when carrying a 30-ton payload, the 10×10 chassis is fully off-road capable. The quad missile canisters (twin in display and testing models) are approximately 7.5 metres long and extend to a vertical position for launch.
As the missiles are ‘hot launched’, there is an integrated blast deflector below the canisters, presumably to prevent too much dust being thrown up, or to protect any prepared surfaces that the Zoljanah TEL may be mounted at with its large hydraulic jacks. Possibly the most unusual thing about Zoljanah is that it needs a 5th axle at all – comparable vehicles for the S-300 need only 4, however, the most modern versions including the S-400 also use semi-trailers with 5 axles. Such a long vehicle potentially has additional space for growth if Iran needs to mount larger missiles on it.
|Zoljanah’s 2012 iteration (top) and current design (bottom)|
|Rear of the Zoljanah TEL with quad missile canisters and blast deflector visible|
Zafar 8×8 Radar Vehicle
Zafar was first shown in 2014. With a payload of 24 tons, probably the only thing preventing Zafar from being a TEL itself is the lesser length compared to Zoljanah. It is also fully mobile like the Zoljanah. The radars that can be mounted on this vehicle have a full 360° of rotation, with storage bins and other equipment supporting them. Each radar vehicle also has a command cabin at the rear, all equipped with beefy air conditioning units. The interior of these cabins is yet to be shown.
|Zafar at its 2014 unveiling|
In the test-fire videos (likely from some years ago), we see several differences with the ‘final’ versions of Bavar:
- None of the radars have their sub-arrays, additional equipment, or IFF antennas. Either these were still being developed, or were not required for the that testing phase.
- The C2 cabin for the whole system sits on the ground between the radar vehicles, not mounted on any vehicle.
- The Sayyad-4 missile is Red, likely for better visibility in cameras capturing the test.
- The Zoljanah TEL only has 2 missile canisters, instead of 4 on the final version. These canisters are also slightly shorter, so that the missile tips are pointing out of them before launch. This has been observed in tests of Sayyad-2 and -3 missiles, likely to preserve the canisters or just out of not needing them for the test.
Mode of Operation versus Stealth Targets
|This diagram depicts bi-static radar operation, with the closest radar representing the missile’s radar receiver|