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Nerds much smarter than me have managed to calculate the numbers on the accuracy of Iran's strike on Nevatim Airbase that took place on October 1st, working out the Circular Error Probability (CEP) of Iran's Medium Range Ballistic Missiles (MRBMs) with Maneuverable Re-entry Vehicles (MaRVs) in what was likely a GPS denied environment. CEP, or median error radius for the mathematical term, measures the radius around the target that the missile will land inside of 50% of the time. There are two main problems with trying to calculate CEP from satellite imagery: firstly, you need to know or make a decent assumption of the target point for the calculation to be worth anything, and secondly, grouping from ballistic missile hits tends to be in an elliptical pattern and not a circle, as ballistic missiles are much more likely to overshoot or undershoot, that hit wide of the target. This is to do with the energy the missile is carrying from it's launch point towards the target. If you've thrown a baseball, tennis ball or cricket ball in an arched throw over a long distance, you'll instinctively understand why. So given that, we can make out two elliptical hit groupings that line up with the direction of likely Iranian missile launch sites:

Now comes the tricky part, making an educated guess on target points. This is all guesswork, but if we assume two target points to match the two ellipses, one target point being the F-35 shelters for the top ellipse, and the other target being the large aircraft hangars that housed refueling, AWACS and presidential transport aircraft. If we assume this as the target points, and use some clever math designed for calculating CEP from an elliptical dataset, the CEP of the missiles used in this attack can be calculated to be around 800-900 meters.

So why could this be? An obvious answer could be GPS jamming. Iran's MRBMs of all types only use a combination of inertial navigation along with satellite navigation/GNSS, so if Israel are successfully jamming potential GNSS/GPS signals at their important military sites, the missiles are only relying on their Inertial navigation systems for terminal guidance. We know that Iran's liquid fueled MRBMs in Emad and Qadr-110, which are based on highly upgraded and upscaled Scud missile designs, are likely not very accurate or maneuverable, even with their upgraded re-entry vehicles. As for Iran's solid fueled MRBMs in Fattah 1 and Kheibar Shekan, we can assume that their MaRVs undergo manouvers to avoid detection and interception, likely including a "pull up manoeuvre" on re-entry to the atmosphere, followed by a "glide phase", before performing a terminal dive towards the target, visible here. Poor execution of this manouver can lead to poor accuracy. As a final and important note, it's highly likely, especially for the second target, that most of the misses are overshoots. If Iran can figure out why their missiles overshot here, due to errors with inertial guidance, poor execution of the "pull up manoeuvre", or both, they can easily double their accuracy and get under 400m CEP, which should be doable. If they can figure out how to defeat Israeli GNSS jamming, CEP could even go under 100m, though I would consider the latter development unlikely.

So where does that leave us with regards to Iranian deterrence against Israeli attacks, and with regards to a likely Iranian retaliatory strike? With the accuracy numbers of Iran's MRBMs as is, Iran has demonstrated the capabilities to hit Israeli soft targets such as electrical facilities (power stations and substations), oil fields, and potentially nuclear power plants. Such a strike would be devastating for Israel. This likely deterred Israel from striking such facilities in their recent attack. But these accuracy numbers are not good enough to be used to hit hardened or isolated Israeli sites effectively. Doing so would require the firing of hundreds of missiles per target, and thousands of missiles per volley of fire. Such is not realistic for Iran, and the collateral damage from such a large attack is likely considered undesirable. This could be why Israel felt comfortable hitting such profile targets in Iran, hitting Iranian air defence systems and radars, along with above ground missile production facilities.

So how can Iran potentially deter such attacks from Israel in future? The first option, familiar to Western diplomats who don't care about the consequences of their actions, would be de-escalation through escalation. Iran could hit sensitive soft targets in Israel with their MRBMs, in the hopes to hurt Israel badly. I think such a course of events is highly unlikely as of now, but I could be wrong.

The second option would be the use of more accurate weapons against Israeli hard and isolated targets. Iran do have more accurate missiles that can work in GNSS/GPS denied environments, in Short Range Ballistic Missiles (SRBMs) with Electro-Optical (EO) seekers, either as surface to surface or surface to ship variants. Such weapons include the Fateh 313, Raad-500/Tankeel, Zolfaqar Basir. All these missiles, except for the unibody Fateh 313 are MaRV capable. These missiles have a much shorter range though, between 500-700km. This could be where the speculation that Iran might launch their strike from Iraq comes into play. As for their high accuracy, we've seen that Ansarallah have been able to hit moving cargo ships with these weapons, and we got a demonstration of the Fateh 313, and potentially Zolfaqar, when Iran launched strikes against US military bases in 2020. Let's just say 5 impacts, 5 direct hits. Iran did more damage with 5 hits from SRBMs in 2020, than with 33 hits from MRBMs in 2024. Such is the power of impoved accuracy from shorter ranges, and EO seekers.

As for more accurate suicide drones that can work under GPS jamming and avoid interception, Iran has the Shahed 238. A jet powered drone with a top speed of between 500-600kph in level flight, and 800kph in a dive. These drones also have EO sensors to allow for accurate strikes even without GPS. Range is limited compared to propeller powered drones with a flight time of only 2 hours, so these will also likely have to be launched from Iraq if they are used, so that's where that speculation comes into play again. The vastly improved speed over the Shahed 136 should reduce the chances of interception by fighter jets, and with its EO seeker it can even lock onto air targets, though any fighter jet can easily outrun it.