The CEP value for the MaRV-Qiam still puzzles me...
Hajizadeh said years ago that they managed to bring CEP down to <10m.
However I always thought he talks about the Khalije Fars or later the Hormoz series or a year ago the Fateh Mobin.
The Fateh-G2 shots against Kurdish seperstist targets would be a peace-time secondary GPS guidance channel.
Then we saw the hit by the Khorramshahr-2, which could have been a lucky 50m CEP shot.
But now showing the MaRV-Qiam with a claimed CEP of 10m is a complete technological shock.
Best and most expensive U.S. 80's cold war technology used an active radar seeker and still only managed >30m.
Trident II, maybe the best ICBM in the world manages 130m at intercontinental range.
I tried to describe all of this in my two previous posts here.
I have reached a explanation for now: The Qiam was a revolutionary breakthrough for Iran and for a good reason it was one of the projects of Shahid Tehrani Moghaddam, a liquid one.
The reason it had no fins was that Iran had managed to produce a very precise INS, likely with a state of the art MEMS based accelerometer and new high precision IFOG gyroscopes. All in a cost effective strap-down configuration.
The resulting system was sensitive and stabile enough to avoid the use of fins on such a light missile.
But the real advantage was that this was the masterpiece of an affordable INS that managed to remain stabile for 1,5 minutes. Those 1,5 minutes would be enough to get the Qiam into space on the right +- 1-5m trajectory, without any physical force other than gravitation affecting it.
The CEP for this Qiam-1 only increased due to boost termination delay and the re-entry phase, getting it into the 130-150m CEP range.
The MaRVed Qiam changed this: The same accelerometer technology that made the Qiam INS so precise was now improved to endure the high G forces occurring during re-entry.
Boost termination error correction and primary: wind-correction system, then enables those accelerometers to correct the 130m error to just 10m.
I thought about astro-nav for the Khorramshahr-2 as a more expensive long range system, in which it would easily fit. But then realized that this system makes primarily sense for a MARV-bus that operates for several minutes. Without MARV-bus, it has nowhere been demonstrated but could be possible that the Iranian INS is precise enough to enable such a results.
The only other option, would be the easy, fragile route: GPS. Here I'm confident enough that it is not used as primary navigation system.
Even Irans wind corrected Zelzal-2 variant Raad 307, as a cheap low-priority system still uses an accelerometer based internal system as primary guidance.
The stress on the MaRV guidance system increases as range goes up: Khorramshahr-2 likely already has its accelerometers be exposed to tens of Gs.
Now the same Qiam based MaRV is re-equipped for the Ghadr and Shahab-3 series, which likely would have the same 10m CEP.
