Blackstone
Brigadier
Two potential problems, 1) it's just one report, and 2) simulations alone are not conclusive. We need to hold our judgements until we see similar reports from other publications.
China Ballistic Missiles and Nuclear Arms Thread
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Well, a simulation is not a full scale, live test. It is just that...a computer simulation. it is a good thing...but it is something that leads to functional, deployed systems, and does not necessarily imply that they are already in place.
For example, the post above concluded with the following:
Sorry, those two statements are not mutually supportive.
I have no doubt that the Chinese are working and working hard on such a system. I have no doubts that other nations like the US, Russia, Japan, and various European nations have done the same.
As to whether they have an operational, in place, system that can ID, locate and track a carrier in the Pacific...well that is a different matter and a conclusion that is not supported by this evidence.
There are numerous problems with such a definitive conclusion. Maybe they do...maybe they don't. There is no doubt that they are researching, developing, and building towards that goal.
But even when they get there...being able to do so reliably in a scenario where those vessels are not using their full capabilities to hide/mask/decoy, etc. their location and being able to do so after the balloons go up are also two entirely different conditions as well.
Fun to talk about. interesting to speculate based on evidence we see. but we are not nearly seeing all of the data on either side of the equation. Nor could we.
For example, the post above concluded with the following:
Preliminary results based on a a simulation that suggest a potential capability, do not equate to a robust system being in place and fielded.
Sorry, those two statements are not mutually supportive.
I have no doubt that the Chinese are working and working hard on such a system. I have no doubts that other nations like the US, Russia, Japan, and various European nations have done the same.
As to whether they have an operational, in place, system that can ID, locate and track a carrier in the Pacific...well that is a different matter and a conclusion that is not supported by this evidence.
There are numerous problems with such a definitive conclusion. Maybe they do...maybe they don't. There is no doubt that they are researching, developing, and building towards that goal.
But even when they get there...being able to do so reliably in a scenario where those vessels are not using their full capabilities to hide/mask/decoy, etc. their location and being able to do so after the balloons go up are also two entirely different conditions as well.
Fun to talk about. interesting to speculate based on evidence we see. but we are not nearly seeing all of the data on either side of the equation. Nor could we.
Brumby
Major
The credibility of the simulation are in the details. Building the necessary space radar to provide coverage is extremely expensive and the effectiveness is subject to a number of trade offs. There is a CBO report dated 2007 that actually discussed the science, issues and trade offs required to put the required constellation in place. As an illustration, the following extracts are helpful to put it in context of coverage, cost and trade offs.
A key trade off is in resolution as it determines coverage and the question is what resolution is necessary for locating and targeting. In perspective, the Pacific Ocean is a wide coverage as compared to the Korean peninsula. In addition, a key infrastructure is data piping as the resolution drives transmission speed and affects consequential delay effect.
Unless we know the assumptions used in the simulation, it is difficult to make a judgement on its credibility.
Hendrik_2000
Lieutenant General
I don't know which planet have you been living . I can tell you that modern life does not exist without computer simulation How else can one built new commercial jet without CFD simulation or structural simulation. For your education simulation mean using assumption and apply the principal of Physic or mechanic and see what is the result if your model is subjected to element whether it is force, heat or air resistance . The advance of computer make it easier since the copious hand calculation with slide rule can now be
done in a jiffy.
Simulation is the next best thing to the real world How else can you built something if you haven't design something. So you create a virtual model or mathematical model in the computer and subjected it to whatever element your model will experience in real life
So going back to the Indian simulation . They know the number of Satellite that China have launched . They can calculate the orbital path of the satellite.Using both the number and path and characteristic of the path ,They can calculate the coverage and using triangulation and accuracy of the Chinese satellite . They can accurately predict if the Chinese can find CBG in pacific.
Of course they say preliminary since they are not privy to actual performance of Chinese Satellite Whatever performance data that they have, they get it from public space . And the Chinese are very secretive about the performance of their surveillance system But it doesn't in anyway negate or depreciate their work .
Simulation is the real thing I earn my living doing simulation every day! So far nothing that I design ever malfunction
broadsword
Brigadier
I can dig that. When you have the parameters, the computers can plot the position of the carriers for the missiles to target. Hitting it as in a computer simulation of war games is a different matter and is not the point Hendrik is trying to make.
Brumby
Major
The issues and variables that go into the tracking algorithm are extremely complex and hence the simulation results are very much subject to the parameters of the modelling itself. For example, the variables may include the average length of time that a single target could be tracked—the mean track life. Under a range of conditions using a simple statistical tracking model developed by consulting firm Booz Allen Hamilton (BAH), the BAH model assumes that a target moves randomly and that other, similar-looking targets are nearby that may be confused with the intended target. Uncertainty exists about both the position and velocity of the target; the amount of uncertainty depends on the performance of the satellite and its radar as well as on the unpredictability of changes in the (assumed) random movement of the target. As the model simulation progresses, the uncertainty can build, making it increasingly difficult for a tracking algorithm to separate the real target from the “confusers.” In reality, targets do not move randomly. More-sophisticated tracking algorithms can take advantage of that fact and even use particular aspects of the radar return to help identify the correct target. However, modeling that type of algorithm requires extensive knowledge about its design as well as a detailed scenario including ECM.
The BAH tracking model uses various inputs:
*Mean access time,
*Mean gap time between access periods,
*Revisit interval,
*Confuser density (the number of objects other than the desired target that the radar might detect),
*The radar’s probability of detecting an object (PD),
*Target location error (the range over which the target’s location could vary), and
*Target velocity error (the range over which the target’s velocity could vary).
You then take the BAH model in a series of Monte Carlo simulations to estimate the range of possible mean track lives for the access periods afforded by the various alternatives, given reasonable ranges for the inputs listed above. You then assume a constant or range of PD and a revisit interval. As input for the Monte Carlo simulations, you then take the range of values that it calculated in the area-coverage analysis for the duration of each target access period, gap times between those periods, and signal-to-noise ratio (which affects PD and target location error). You then have a generated distributions of those parameters under the conditions required for observing a moving target with a given radar cross section of say “X” square meters and a velocity of “Y” meters per second. You then have to assume a nominal target location accuracy in the range direction; plus target location accuracy in the cross-range direction estimated from the signal-to noise ratio using published relationships.
The mean track life itself would range depending on a number of variables :
- Constellation profile and capabilities (including orbital height);
- Signal processing capabilities
- Satellite yaw angle while scanning
Ultra
Junior Member
How old are these pictures? Top one looks like DF-5 to me. Bottom one not so sure, I am guessing IRBM.
I suspect the DF-5 is a +20 years old picture, but the DF-4A (bottom) is from a recent news report.
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