The unveiling of an Iranian copy of the Lockheed Martin RQ-170 unmanned aerial vehicle (UAV) overshadowed other, potentially more significant, revelations that emerged when Supreme Leader Grand Ayatollah Ali Khamenei visited the Islamic Revolution Guards Corps (IRGC) Aerospace Force on 11 May.
Arguably the most important weapons displayed for Khamenei were new variants of the Fateh-110 tactical ballistic missile called the Hormuz-1 and Hormuz-2.
IRGC Aerospace Force commander Brigadier General Amir Ali Hajizadeh said the Hormuz-1 was an anti-radiation variant and Iranian television showed the supreme leader watching a video of a test in which a missile destroyed a target with a radar antenna.
"The missile destroyed a 20 ft [6 m] container at a distance of 300 km during test fire," Brig Gen Hajizadeh was quoted as saying.
An operational anti-radiation version of the Fateh-110 would in theory allow Iran to suppress the radars essential to the ballistic missile defence systems deployed in the Arab Gulf states.
It could also be used to target naval vessels by locking on to the energy emitted by their radars. Iran already has an anti-ship version of the Fateh-110 called the Khalij Fars, but this uses electro-optical/infrared (EO/IR) terminal guidance.
Brig Gen Hajizadeh said the Hormuz-2 was an anti-ship missile, but the photographs of the event showed that, like the Hormuz-1, it had what appeared to be a radio frequency-transparent radome and not a window on its nose for EO/IR guidance. This raises the possibility that it uses active or passive radar terminal guidance. The latter is more likely as the missile would be less vulnerable to electronic countermeasures, but that would make it essentially the same as the Hormuz-1.
The IRGC displayed a previously unseen submunition warhead on what looked like a Fateh-110, although the missile was confusing labelled as the Zelzal Barshi. The 610 mm Zelzal heavy rocket is the unguided system developed into the Fateh-110 by fitting a guidance unit with canards between its warhead and motor, while 'barshi' is the Persian word for rain and is used by the IRGC to describe cluster munitions.
The missile's warhead section was cut away to show submunitions with pointed noses and cylindrical bodies inside; the Fars News Agency reported it contains 30 such bomblets, each weighing 17 kg (collectively weighing 510 kg).
Iran has previously announced that it has developed barshi warheads for its larger ballistic missiles - a development that would help mitigate their inaccuracy by turning them into more effective area-attack weapons - but this is the first time one has been unveiled for the Fateh-110, which IRGC officers say is a highly accurate weapon. The IRGC may consequently have developed the submunitions warhead for the unguided Zelzal, rather than its guided counterparts.
The IRGC created more confusion by labelling a smaller-diameter missile with guidance canards like those on the Fatah-110 as a Fajr-5: the name of Iran's 333 mm unguided rocket. This raises the possibility that Iran is developing a guided version of the Fajr-5 as it did with the Zelzal. The missile would be rail launched as the canards do not retract to fit inside the tube used with the unguided version.
This development could be a concern for Israel as Iran has already supplied Fajr-5s to Hizbullah in Lebanon and Hamas in the Gaza Strip. A guided version would allow the militants to carry out more accurate strikes up to 75 km into Israeli territory.
Another intriguing weapon system on display was the Ya Ali cruise missile, which is similar in general layout to, but somewhat smaller than, China's YJ-62 (export designation: C-602).
Like the YJ-62, the Ya Ali has an inlet for an air-breathing engine, possibly a version of the Tolou turbojet Iran already uses to power its longer-range anti-ship missiles, and wings to generate aerodynamic lift and extend its range, which the Fars News Agency reported to be 700 km.
These wings do not retract into the missile's body as they do on the YJ-62, meaning the Ya Ali could not be launched from a container. While the missile on display may have been an inaccurate mock-up or test vehicle, it had a large booster motor fitted with wings rather than fins, indicating it has been designed to be used on a cruise missile with fixed wings.
Two surface-to-air missile (SAM) systems were displayed during the 11 May event, one of which, the 3 Khordad (the Persian date that Iran recaptured Khorramshahr in 1982), was revealed as a new system. However, the 3 Khordad appeared to be very similar to one seen in Iranian television footage broadcast in September 2012 showing the recently unveiled Ra'ad SAM being fired.
The Fars News Agency reported that the 'new' 3 Khordad can simultaneously engage multiple targets at a range of 50 km and an altitude of 25,000 m: similar statistics to those given for the Ra'ad.
A possible explanation is that the 3 Khordad is the transporter erector launcher and radar (TELAR) for the SAM system, while the Ra'ad name refers just to the loader-launcher vehicles controlled by the TELAR as they do not have their own integrated engagement radars.
The other SAM displayed on 11 May was labelled as the Tabas and was very similar to the 3 Khordad, but had a different radar. While the 3 Khordad TELAR has what looks somewhat like the phased-array radar used on the Russian Buk-M2 system, the radar on the Tabas was similar to the less sophisticated 'Fire Dome' used on the Buk-M1.
The unveiling of what the IRGC described as a reverse-engineered version of the RQ-170 reconnaissance UAV that crashed in Iran in December 2011 attracted most international media attention, but was not seen flying.
The Fars News Agency reported that the UAV had been equipped with a bombing capability to attack naval vessels, which would involve fitting an internal weapons bay in place of the original's surveillance payload.
It still seems unlikely this will develop into a major programme as the Iranians will presumably struggle to replicate the advanced radar-absorbing materials and the sophisticated avionics needed to stabilise a flying-wing UAV.