Yuanwang 4 Sunk by Carrier killer missle DF21 in One test?

[houshanghai]

it is reported that PLAN's retired intellegence-ship Yuanwang4 got sunk by AC-killer missle DF21 in one test.

Yuanwang 4 once was PLAN's intellegence ship and retired after one accident. Its displacement is over 10K tons.

Before the test, One cube reflector and lots of antennas were fitted on Yuanwang 4 ,in oder to increase the RCS of the ship .Thus, the RCS of Yuanwang4 seemed as large as one Aircraft carrier ,seen from Radars. In the test of AC-killer missle DF21,Yuanwang4 could play the role of the target ship--one aircraft ship.

Here is Yuanwang 4 after the refitment. the cube reflector can be seen easily.

cd link:

http://lt.cjdby.net/thread-1055580-1-1.html

top81 link:
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this news was posted in huanqiu website ,it's one of official forum
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[ao333]

Let's wait for a month or so to see if experts pick this up.

 

[SXNJ]

I doubt this news because if it is true the west media will definitely report it.

 

[rockstarIN]

American spy satellites must have picked up any such test, specially such a huge missile test...

 

[CardSharp]

can someone explain what a cube reflector is ? and is the equipment on board meant to provide trajectory data on the MaRV?

 

[gambit]

I doubt this news because if it is true the west media will definitely report it.

Let us see how can this be true...

Yuanwang 4 once was PLAN's intellegence ship and retired after one accident.

Does this mean the ship was too crippled to move under its own power? If necessary, the ship can be towed to the testing area and anchored to serve as a static target. But there is no reason to doubt the PLAN's technical ability to repair and re-equip the ship with only minimum propulsion capability to serve as a dynamic target. Verdict: Feasible.

Before the test, One cube reflector and lots of antennas were fitted on Yuanwang 4 ,in oder to increase the RCS of the ship .Thus, the RCS of Yuanwang4 seemed as large as one Aircraft carrier ,seen from Radars.

Nothing technically in error here. Target enhancement in the appropriate medium, ie radar or infrared, is common practice. This falls under the controlled environment criteria.

This is a corner reflector...

Radar signals will have multiple reflections inside these ideal 90deg corners. These passive reflectors are often used by small crafts to enhance their radar returns for larger ships for safety reasons.

Verdict: Feasible.

So if it is technically feasible to equip a ship to serve as an expendable target, the next questions should be about the testing conditions themselves:

- Was the test for radar targeting only, meaning was there an airborne DF-21 radar set installed in an aircraft or even in an expendable test warhead, intended to test the detection and tracking capability of this radar set?

- Was the target ship static or dynamic?

- Was the target ship's radar enhancement reduced in anyway? This is important because if the ship's enhanced RCS was gradually reduced, it will give the designers evidences as to the radar's true capability depending at which reduced level did the target ship was lost. This could mean the warhead could target ships smaller than an aircraft carrier hence a better weapon.

- Were there any countermeasures? It would be foolish to assume an adversary would not deployed passive/seduction/distraction defenses.

So if the report is true that the ship was sunk, it would be safe to assume that all questions have been satisfied.

 

[CardSharp]

Nothing technically in error here. Target enhancement in the appropriate medium, ie radar or infrared, is common practice. This falls under the controlled environment criteria.

This is a corner reflector...

Radar signals will have multiple reflections inside these ideal 90deg corners. These passive reflectors are often used by small crafts to enhance their radar returns for larger ships for safety reasons.

Verdict: Feasible.

Does this confirm radar guidance if the ship was indeed used to test the DF-21?


and how would one test the infrared sensors as had been suggest the system might have

Thrusters vs. Fins

The answer is, of course, both if you got ‘em. But each mechanism for changing the warhead’s trajectory will require its own target tracking system. Ideally, you want to make changes in trajectory as early as possible since the longer you have to accelerate to the new trajectory, the lower the magnitude of the required trajectory (and, among other things, the more control you have over the final result). If the DF-21D warhead uses infrared sensors—putting aside the question of whether or not China has the required technology for a moment—then it will have to use them during the coast phase of its trajectory. Otherwise, the heat of reentry will blind the sensor if it tries to use them after it reenters the atmosphere, say something like 50 km altitude to pick a round number.

At these altitudes, the warhead cannot use aerodynamic surfaces to change its direction. So it will need thrusters—little rocket engines—to change its direction. Of course, China does has plenty of experience with fine tuning trajectories with small thrusters from its satellite insertion operations. The most likely method China might use for such a platform is a “bus” that holds the warhead while little thrusters change its position. What sort of thrust would they need? Assuming the warhead makes its corrections as the warhead passes below 100 km altitude in order to minimize the time the target has for changing its direction (again, I’m pulling these numbers out of thin air) it would have enough umph to change the velocity of the warhead/bus combination by 0.6 km/s. (This is calculated by assuming the thrusters need to change the direction of the warhead by 13 km in the 22 seconds the warhead has between when it passes 50 km—the minimum altitude I assume it can still use IR sensors). That, in turn, requires a little more than three G’s (three times the acceleration of gravity). That is probably about the requirements needed for China’s ASAT weapon tested in January 2007. So that seems possible.

If the warhead shuts down its IR sensor as it passes 50 km altitude, it is about 22 seconds before impact. It is too much to hope that the carrier can change its direction or even its speed in those few remaining seconds so the we can expect; the George H. W. Bush displaces 100,000 tons! That means the warhead can “safely” extrapolate the position the carrier will be 22 seconds after its tracker shuts down. During those 22 seconds, the Bush could travel 370 meters, which is about the length of the Bush (333 meters) but five times the beam of the Bush (77 meters). How likely a hit will be will depend on two things: how accurately the tracking system can determine the position and velocity and how finely it can tune its acceleration to match the desired trajectory

 

[gambit]

Does this confirm radar guidance if the ship was indeed used to test the DF-21?

Now you are getting to the nitty-gritty of these tests. The answer is yes. If the test is a non-destructive one, even if an expendable test warhead was used, the ship would provide real time update of the warhead's radar tracking capability. The reflectors enhancements are dead giveaways. I have been involved in these types of tests before off Florida. I know how they are done.

and how would one test the infrared sensors as had been suggest the system might have

Simple flares will do. But assuming this is the target ship, judging from the upper deck layout, I highly doubt that this is an IR test, or at best a very simple one for a simple IR sensor design. An aircraft carrier's deck have highly unique IR hot spots that exists nowhere else. Why would anyone ignore this uniqueness when there are plenty of sophisticated IR sensor algorithms available to further confirm the existence of such a ship below and secure track?

 

[Capt.Popeye]

Let us see how can this be true...


Does this mean the ship was too crippled to move under its own power? If necessary, the ship can be towed to the testing area and anchored to serve as a static target. But there is no reason to doubt the PLAN's technical ability to repair and re-equip the ship with only minimum propulsion capability to serve as a dynamic target. Verdict: Feasible.


Nothing technically in error here. Target enhancement in the appropriate medium, ie radar or infrared, is common practice. This falls under the controlled environment criteria.

This is a corner reflector...

Radar signals will have multiple reflections inside these ideal 90deg corners. These passive reflectors are often used by small crafts to enhance their radar returns for larger ships for safety reasons.

Verdict: Feasible.

So if it is technically feasible to equip a ship to serve as an expendable target, the next questions should be about the testing conditions themselves:

- Was the test for radar targeting only, meaning was there an airborne DF-21 radar set installed in an aircraft or even in an expendable test warhead, intended to test the detection and tracking capability of this radar set?

- Was the target ship static or dynamic?

- Was the target ship's radar enhancement reduced in anyway? This is important because if the ship's enhanced RCS was gradually reduced, it will give the designers evidences as to the radar's true capability depending at which reduced level did the target ship was lost. This could mean the warhead could target ships smaller than an aircraft carrier hence a better weapon.

- Were there any countermeasures? It would be foolish to assume an adversary would not deployed passive/seduction/distraction defenses.

So if the report is true that the ship was sunk, it would be safe to assume that all questions have been satisfied.

Good points raised above. However the underlined parts are the most important.
1. w.r.t. static/dynamic- since the intended target/s for this missile would be (swiftly) dynamic.
2. w.r.t RCS- this will give a truer picture of the missile's seeker and lock-on abilities.
3. w.r.t. Countermeasures- if the test missile was able to overcome any/all countermeasures, stands to reason that test bench-marks were higher.

BTW, Youtube has numerous videos of missile hits on decommisioned ships, lying dead in the water.
Those videos recorded little achievement, apart from being posted on Youtube.

 

[gambit]

1. w.r.t. static/dynamic- since the intended target/s for this missile would be (swiftly) dynamic.

True...But in the interest of accurate data keeping, prior to a dynamic target, the ship would be static, then with increasing speed and maneuvers.

2. w.r.t RCS- this will give a truer picture of the missile's seeker and lock-on abilities.

Am willing to bet dollars to doughnuts that, assuming this report is true, that the Chinese have incrementally decrease the target ship's RCS. It is not that difficult to do. The target radar enhancers I used to work with are mechanically collapsible and some even are inflatables...

EchoMax Radar Reflectors - Foreword

Echomax inflatable reflectors fold down into a neat pocket size, an ideal addition to the emergency grab bag.

There is no reason, other than budgetary, not to perform these tests with incrementally reduced RCS.

3. w.r.t. Countermeasures- if the test missile was able to overcome any/all countermeasures, stands to reason that test bench-marks were higher.

Therein lies the problem -- an adversary's defensive measures are usually unknown regarding sophistication in technology and deployment in times of combat. All the PLAN can do is guess.

 

[Obambam]

Hope someone can shed some light on this test. Sinking a destroyer or not matters very little. Destroying the control tower, electonic equipments, aircrafts and run way is suffice to put it out of service. I'd assume that it will cost a lot to have it towed back to base too.

 

[gambit]

American spy satellites must have picked up any such test, specially such a huge missile test...

It would not be a 'huge' test but a ballistic missile launch would earn notice.

International Code of Conduct Against Ballistic Missile Proliferation (ICOC)

ICOC Principles and Purpose

The Code calls for greater restraint in developing, testing, using, and transferring ballistic missiles. It does not prohibit owning missiles or discriminate against their use in conducting peaceful operations in outer space. The key elements of the Code require state signatories to:

<snipped>

# consider, on a voluntary basis (including on the degree of access permitted), inviting international observers to land (test-) launch sites
# exchange of pre-launch notifications on ballistic missile and space launch vehicle launches and test flights

China and the draft ICOC

Although not a member of the MTCR, China was invited to participate in the ICOC negotiations. China was among the 86 delegations involved in the Paris talks as well as in the final negotiations in Madrid and The Hague. However, Beijing ultimately chose not to subscribe to the Code. Kong Quan, a Chinese Foreign Ministry spokesperson, announced on 12 November 2002 that Beijing would not take part in the agreement of the Code after some of its proposed amendments were rejected. Kong stated that, "[China] regrets that the suggestions were not accepted. The issue created difficulty for China to participate in the code." Some of the reasons cited for China's reluctance to sign the agreement include certain aspects of the transparency and confidence-building measures in the Code. Furthermore, it was noted that China wanted the code to prohibit technology transfers that are a threat to China's security, such as the U.S. transfers to Taiwan.

Since China chose not to be a signatory, China can launch any ballistic missile test or space bound vehicle at any time. Notifications would merely be a courtesy instead of an obligation. But China does not have as much testing areas as the US does, especially when the test involve a land based missile and I doubt that live missile tests would be conducted near reconnaissance flight paths coming from Taiwan or SKR/Japan. Could be wrong, though. Further, we can be assured that there are US subs tracking PLAN ships movements so any live missile tests would be confirmed through many methods.

 

[gambit]

Hope someone can shed some light on this test. Sinking a ship or not matters very little as long as it is capable of destroying the control tower, electonic equipments, aircrafts and run way is suffice putting it out of operation. I'd assume that it will cost a lot to have it towed back to base too.

It is not as easy to sink an Enterprise class ship as many would like to believe.

bigEfire.com Ordeal of the USS Enterprise

The USS Enterprise came within a step of dying on 14 January, 1969. Exploding weapons on the flight deck blew the ship apart all the way down to the waterline. Flaming jet fuel from the thirty two aircraft involved cascaded down through those many great wounds firing the interior of the ship.

The US learned much from WW II on large warship designs regarding compartmentalization to reduce the odds of sinking. If the above was at wartime, the Enterprise would have effect emergency deck repairs and continue to prosecute the war. Air operations would be limited but not completely ceased. One hit would not sink it.

 

[Obambam]

It is not as easy to sink an Enterprise class ship as many would like to believe.

bigEfire.com Ordeal of the USS Enterprise

The US learned much from WW II on large warship designs regarding compartmentalization to reduce the odds of sinking. If the above was at wartime, the Enterprise would have effect emergency deck repairs and continue to prosecute the war. Air operations would be limited but not completely ceased. One hit would not sink it.

Like I said, sinking it or not matters very little. What matters is the ability to put it beyond striking distance and if need be destroying the equipments and aircrafts onboard is suffice.

 

[CardSharp]

It is not as easy to sink an Enterprise class ship as many would like to believe.

bigEfire.com Ordeal of the USS Enterprise

The US learned much from WW II on large warship designs regarding compartmentalization to reduce the odds of sinking. If the above was at wartime, the Enterprise would have effect emergency deck repairs and continue to prosecute the war. Air operations would be limited but not completely ceased. One hit would not sink it.

China would probably prefer a method that can put a carrier out of operations without sinking it.

Would it be possible for a solid penetrator coming in from reentry speed put a carrier out of operation? What some kind of runway disabling munition?