China is Testing DF-21 Anti-ship Ballistic Missile

[Lankan Ranger]

China is Testing DF-21 Anti-ship Ballistic Missile

The commander of U.S. military forces in the Pacific said Thursday that the buildup of Chinese armed forces is continuing "unabated" and Beijing's goal appears to be power projection beyond Asia.

"China's rapid and comprehensive transformation of its armed forces is affecting regional military balances and holds implications beyond the Asia-Pacific region," said Adm. Robert F. Willard, the Pacific Command leader.

"Of particular concern is that elements of China's military modernization appear designed to challenge our freedom of action in the region."The comments in testimony to the House Armed Services Committee are likely to fuel an ongoing debate inside the U.S. government among military, policy and intelligence officials over whether China's military buildup is limited to a future conflict with Taiwan or whether China harbors global military ambitions.

China also will deploy its own aircraft carrier by 2012 and currently has more than 60 submarines, he said.China is "developing and testing a conventional anti-ship ballistic missile based on the DF-21/CSS-5 medium-range ballistic missile designed specifically to target aircraft carriers," Adm. Willard said in his prepared statement.

ASIAN DEFENCE: China is Testing DF-21 Anti-ship Ballistic Missile to Target US Aircraft Carriers: US Adm. Willard

 

[Agnostic_Indian]

@gambit @sancho @Oscar @anybody
How is the probability Df 21 hitting a moving aircraft carrier different than a missile defence system taking out incoming ballistic missile with another ballistic missile, later should be more difficult given the small size and speed of incoming ballistic missile, isn't it ?

 

[gambit]

@gambit @sancho @Oscar @anybody
How is the probability Df 21 hitting a moving aircraft carrier different than a missile defence system taking out incoming ballistic missile with another ballistic missile, later should be more difficult given the small size and speed of incoming ballistic missile, isn't it ?

Let me put it this way...

In a head on intercept, assuming the target does not have any lateral (side to side) deviation, you are essentially looking at a 'stationary' target. Also assuming that you have perfect sensor/guidance to create a perfect course alignment between interceptor and target in this head on intercept, your success is certain. The only reason why you would fail is that if you miss, you have statistically zero chance of reacquiring the target because both you would be so far from each other that your interceptor would run out of fuel going around to try to catch it.

But let us say that your interceptor missed and is making a turn to change the head on intercept into a tail chase intercept. The problem now is that because you are in a tail chase situation, ideally you should have 3x the target's estimated speed in order for you to make an intercept. Yes, a tail chase is technically an intercept.

For the DF-21D hitting a ship. In this situation, you would be looking at a target that has lateral (side to side) course deviation. I do not mean literally zig zag back and forth side to side. I mean that the target is moving across my field of view and that the target is making this motion continuously.

This is what I would be seeing. Just like how a falling bomb would see the ship. That curve is that lateral course deviation. The problem for me is that I must have CONTINUOUS target course deviation updates. I do not care if my updates came from radar, IR, data link, or even God Himself. If the target moved one meter to one side, I need to know about it. I already know the target is getting closer to me.

So spatially speaking, navigation laws for the DF-21D to ship intercept is much more difficult to write to compensate for the uncertainty of where my target is going to be, like the WW II example above.

One example of such laws is 'proportional navigation'...

Proportional navigation - Wikipedia, the free encyclopedia

The basis of proportional navigation was first discovered at sea, and was used by navigators on ships to avoid collisions.

If I can steer to avoid collisions, I can also steer to produce collisions. To either avoid or produce collisions, I must mentally produce navigation laws that take into consideration target's lateral (field of view) displacement. If I steer 5 degrees/sec, will that be enough to avoid a collision? Conversely, since the target moved 5 degrees/sec laterally in my field of view, how much can I steer to produce or resume a collision course.

Pure pursuit - Wikipedia, the free encyclopedia

Pure pursuit is a type of pursuit curve used in aerial combat in which an aircraft pursues another aircraft by pointing its nose directly towards it.[1] This is in contrast with lead pursuit, in which the chasing aircraft points ahead of the aircraft it is following (typically used when attempting a gun attack) and lag pursuit, in which the chasing aircraft points behind the aircraft it is following (typically used when attempting a rear-aspect missile attack).

Pursuit navigation laws are simpler to write, even if taking that 3x speed into requirement. The application here is the typical 'dogfight' aerial combat engagement with the tail chase situation preferred by every pilot. The pilot would lead the target and hope his bullets would intercept the target at a spatial location ahead of the target. There are lateral course deviations in ACM, of course, but the starting point is the pursuit (tail) position.

For both anti-ballistic missile and anti-ship interception schemes, the common weakness is in sensor/navigation/guidance/steerage (control) integration.

Guidance, navigation and control - Wikipedia, the free encyclopedia

Guidance, navigation and control (abbreviated GNC, GN&C, or G&C) is a branch of engineering dealing with the design of systems to control the movement of vehicles, especially, automobiles, ships, aircraft, and spacecraft.

The anti-ballistic missile defense interception scheme is more difficult to achieve because of the high closing speed between bodies. The ballistic warhead is descending at possibly double digits Mach and the interceptor is rising as fast as possible to destroy the target as high an altitude as possible. Add both speeds and you have the closing speed. Probably like 15-20 Mach. The sensor/nav/guidance integration package must acquire the target as early as possible, calculate as many spatial intercept points as possible and do it from the maximum detected altitude, and send steerage commands as fast as possible. So the difficulties here lies not in complex navigation laws but in quickly creating solutions from simpler laws.

For the anti-ship ballistic missile interception scheme, the ship's approaching speed is zero, that leave only the ballistic warhead's descent speed to calculate closing speed, which is may be 10 Mach. If the DF-21D warhead does not have steerage mechanisms, such as movable fins or control jets, to compensate for the ship's lateral field of view deviations, and sufficiently sophisticated navigation laws for those deviations, if the warhead missed by just one meter, the ship win.

 

[j20blackdragon]

if the warhead missed by just one meter, the ship win.

Not if the "warhead" is a torpedo.

Think outside the box.

 

[cnleio]

Let me put it this way...
if the warhead missed by just one meter, the ship win.

Thousands of SADARM warheads

 

[cirr]

（The so-called）DF-21D ASBM is passe。

Something far more capable is on the way，making large surface vessels within the area bounded by the Chinese mainland and the 2nd chain of islands nothing but sitting ducks。

 

[Black Eagle 90]

China is Testing DF-21 Anti-ship Ballistic Missile

The commander of U.S. military forces in the Pacific said Thursday that the buildup of Chinese armed forces is continuing "unabated" and Beijing's goal appears to be power projection beyond Asia.

"China's rapid and comprehensive transformation of its armed forces is affecting regional military balances and holds implications beyond the Asia-Pacific region," said Adm. Robert F. Willard, the Pacific Command leader.

"Of particular concern is that elements of China's military modernization appear designed to challenge our freedom of action in the region."The comments in testimony to the House Armed Services Committee are likely to fuel an ongoing debate inside the U.S. government among military, policy and intelligence officials over whether China's military buildup is limited to a future conflict with Taiwan or whether China harbors global military ambitions.

China also will deploy its own aircraft carrier by 2012 and currently has more than 60 submarines, he said.China is "developing and testing a conventional anti-ship ballistic missile based on the DF-21/CSS-5 medium-range ballistic missile designed specifically to target aircraft carriers," Adm. Willard said in his prepared statement.

ASIAN DEFENCE: China is Testing DF-21 Anti-ship Ballistic Missile to Target US Aircraft Carriers: US Adm. Willard

Will China going to test its Older Missiles of 70s,80s and 90s with convential war heads on India if a war between the two nations break out???

I am sure than it will be impressive to see 100s of Older missiles hitting Indian Military bases all over India... WOW!!!