January 31, 2019

Chinese DF-21D and DF-26 Missile Accuracy

Drawing from KQN's and Josh's interesting comments of 29 January and 31 January 2019 below this Submarine Matters' article of 29 January 2019.

The DF-26's accuracy improves with its manoeuvrable re-entry vehicle (in the terminal phase). It also likely uses Chinese BeiDou GPS, plus some form of seeker. 

[Pete Research - Looking at the BeiDou GPS wiki entry the "restricted military service has a location accuracy of 10 centimetres" [ie 0.1m] (though footnote 53, Science China 2012 "proof" is now a "dead" link). So theoretically Chinese DF-21D ASBMs and DF-26 IRBMs may have a CEP of 1 meter!]


Believed to be missile warhead craters in a Chinese desert, carrier sized, target. Satellite image originally in Want China Times (dead link) via Business Insider Australia, January 26, 2013 and reproduced in many other sources)
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There are some commercial satellite photos on the web, here (and see above) of Chinese land test targets simulating an aircraft carrier. You can clearly see the craters right in the middle of the target. Of course the target is not mobile while a US nuclear carrier is. The shorter (around 1,500 km minimum) range DF-21D's main targets are carriers including those in the main US northeast Asia naval base at Yokosuka, Japan. While the much longer (around 4,000 km) range DF-26 is for fixed targets like Andersen AFB Guam and the SSN naval base at Guam. 

DF-21Ds and DF-26s might be deployed at the new 2nd artillery (missile) base on China's Hainan Island (with Chinese SSBNs based nearby). Like many Chinese bases, deep dug protective tunnels for missiles and submarines are likely.


There seems to be little evidence that the DF-26 has an anti-shipping warhead like DF-21D, but it is  possible. The PLANs ability to target moving ships outside the first island chain is fairly limited right now so I wouldn't expect Chinese DF-21Ds and DF-26s to be deployed to hit ships outside the island chain yet.

It is worth noting again that geography and US foreign bases force the Chinese to test their weapons very far from the sea, like the desert in northwest China. The anti-ship targeting abilities of the DF-26 and DF-21D cannot be tested on an actual sea target. Test at sea would allow the US to learn about as much from the test as the Chinese. This has to impact Chinese confidence in these missiles somewhat.

A rough minimum range estimate, in kms, from Chinese launch points, estimated number of China's DF-21Ds and DF-26s, and some possible targets, are above.
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KQN, Josh and Pete

5 comments:

Anonymous said...

A lot of articles had already been written about the DF-21D's range and now its supposedly accuracy. The problem about real time maritime reconnaissance strike is not about any of these ancillary factors as they are a given but rather the issues of a kill chain and the ability to hit not just a moving but a heavily defended target. Until the Chinese can actually demonstrate an end to end test, at least it will move this conversation along but until then it is merely propaganda by the Chinese.

It would be of interest if there are serious conversations about the Chinese maritime surveillance capabilities, their sensor fusion setup, their C2 decision making that ultimately leads to any authorization. This whole process and the flight time will mean the supposedly target is long gone from its target location besides the fact that the target might simply be just off board decoys.

Brumby

Pete said...

Very true Brumby

As explained in the article China is unlikely to mount an end to end, moving vessel test, because this would reveal secrets of these missiles (and guidance network), particularly to the US.

Against moving targets plunging warhead manoeuvring (using warhead sensors, ground stations, GPS and active reconnaisance satellites) is essential. But China's island ringed geography and the broad coverage of US, Japanese and Taiwanese sensors prevents secure testing.

Chinese testing from an open ocean client state, such as a South Pacific or Indian Ocean island, may be a future possibility.

Regards

Pete

Tri-ring said...

My question towards a ballistic missile hitting a moving object is during black out where the super heated plasma of the re-entry vehicle should shut out any telemetry making it impossible to re-acquire target position through GPS or any other communication.

Pete said...

Hi Tri-ring

In a better known manned capsule reentry that long period of super heated plasma interference occurs because the capsule is skimming in such a way to SLOW THE CAPSULE DOWN then use parachutes to slow down before human survivable descending to the water or Kazakh/Russian steppe.

For a warhead reetry vehicle there is NO LONG PERIOD OF SLOW DOWN so it can enjoy almost uninterrupted contact with reconnaisance satellites [1] because it follow a (non-skimming) ballistic trajectory through the plasma producing band. A MARV probably hits the ground (or just above it - air burst) at Mach 10+.

Also the reentry vehicle has its own onboard readjustment sensors (eg. active radar)[2] hooked up to retro-rocket manoeuvring.

[1] radar, optical and infrared. https://en.wikipedia.org/wiki/DF-21#DF-21D_(CSS-5_Mod-4)_Anti-ship_ballistic_missile :
"Jianbing-5/YaoGan-1 and Jianbing-6/YaoGan-2 satellites offering targeting information from synthetic aperture radar (SAR) and visual imaging respectively."

[2] https://en.wikipedia.org/wiki/DF-21#DF-21D_(CSS-5_Mod-4)_Anti-ship_ballistic_missile

"DF-21D has radar and optical sensors for tracking,"

Regards

Pete

Pete said...

FAS, "Ballistic Missile Basics" June 2000 https://fas.org/nuke/intro/missile/basics.htm

"RVs possess a tremendous amount of kinetic energy, which must be dissipated during reentry as the vehicles decelerate to their impact or landing velocity. The RV reenters the Earth's atmosphere at velocities of up to Mach (M) 25. As the RV passes through the atmosphere, atmospheric friction decelerates it to below [Mach] 1,..."

"...blunt nose RVs [1] are heated less than slender ones; and lifting RV designs, which use the glider principle, produce less heat than ballistic hyperbolic descent designs because their velocity is typically lower. Thus, a full evaluation of thermal impacts during reentry is dependent on both vehicle- and mission-specific criteria."

[1] https://upload.wikimedia.org/wikipedia/commons/thumb/d/da/Mk_6_reentry_vehicle_on_display_at_National_Atomic_Museum.jpg/170px-Mk_6_reentry_vehicle_on_display_at_National_Atomic_Museum.jpg

I rest my case :)