HUAM missile defense

HUAM missile defense

1 About HUAM missile defence

We use CNN article about HUAM missile defense posture.

For more see:

https://edition.cnn.com/2017/03/07/asia/north-korea-japan-us-ballistic-missile-defense/index.html

2 Missiles Test Events Data

Here we use open source data discussed in the previous topics:

1.Hwasong-12 threat to HUAM - https://rpubs.com/alex-lev/478747

2.Demystifying THAAD Reliability - https://rpubs.com/alex-lev/477708

3.Demystifying AEGIS Reliability - https://rpubs.com/alex-lev/461808

No official information is available about PAC-3 IRBM intercept reliability so far. Here we use some questionable estimate of Patriot PAC-3 as 10 hits out of 11 trials.

  1. https://slate.com/news-and-politics/2003/03/how-good-are-those-patriot-missiles.html

3 Bayesian posterior samples for missiles reliability

library(rstan)
library(BH)
library(bayesplot)
rstan_options(auto_write = TRUE)
options(mc.cores = parallel::detectCores())

#STAN binomial model
print(stan_model(file = "binom.stan"))
## S4 class stanmodel 'binom' coded as follows:
## data{
##     int n; // Number of trials
##     int x; // Number of success
##     int a; // Alpha
##     int b; // Beta
##   }
## 
##   parameters{
##     real<lower=0,upper=1> p; // unknown parameter
## }
## 
##     model{
##       //p~uniform(0,1);
##      p~beta(a+1,b+1);
##       x~binomial(n,p);
##       //x ~ beta_binomial(n, a+1, b+1);
##      
##      
##     }
##     
##   generated quantities {
##   real pp;
##   pp = beta_binomial_rng(n, a+1, b+1);
##   }
## 
## 
#KN17 N=6,X=3
data_list_kn17 <- list(n=6,x=3,a=2,b=2)
fit.kn17 <- stan(file = "binom.stan",data = data_list_kn17,chains = 2,
            iter = 5000,warmup = 1000,seed = 12345)
print(fit.kn17)
## Inference for Stan model: binom.
## 2 chains, each with iter=5000; warmup=1000; thin=1; 
## post-warmup draws per chain=4000, total post-warmup draws=8000.
## 
##       mean se_mean   sd   2.5%   25%   50%   75% 97.5% n_eff Rhat
## p     0.50    0.00 0.14   0.24  0.41  0.50  0.60  0.76  3005    1
## pp    2.96    0.02 1.60   0.00  2.00  3.00  4.00  6.00  7997    1
## lp__ -8.81    0.01 0.71 -10.83 -8.98 -8.54 -8.37 -8.32  3556    1
## 
## Samples were drawn using NUTS(diag_e) at Thu Mar 28 13:12:07 2019.
## For each parameter, n_eff is a crude measure of effective sample size,
## and Rhat is the potential scale reduction factor on split chains (at 
## convergence, Rhat=1).
stan_hist(fit.kn17)

s1.kn17 <- extract(fit.kn17)


#AEGIS N=52,X=42
data_list_aegis <- list(n=52,x=42,a=2,b=2)
fit.aegis <- stan(file = "binom.stan",data = data_list_aegis,chains = 2,
                 iter = 5000,warmup = 1000,seed = 12345)
print(fit.aegis)
## Inference for Stan model: binom.
## 2 chains, each with iter=5000; warmup=1000; thin=1; 
## post-warmup draws per chain=4000, total post-warmup draws=8000.
## 
##        mean se_mean    sd   2.5%    25%    50%    75%  97.5% n_eff Rhat
## p      0.78    0.00  0.05   0.66   0.74   0.78   0.81   0.87  3159    1
## pp    25.99    0.12 10.32   7.00  18.00  26.00  34.00  45.00  8000    1
## lp__ -31.37    0.01  0.70 -33.40 -31.54 -31.09 -30.92 -30.86  2885    1
## 
## Samples were drawn using NUTS(diag_e) at Thu Mar 28 13:12:11 2019.
## For each parameter, n_eff is a crude measure of effective sample size,
## and Rhat is the potential scale reduction factor on split chains (at 
## convergence, Rhat=1).
stan_hist(fit.aegis)

s1.aegis <- extract(fit.aegis)


#THAAD N=11,X=5
data_list_thaad <- list(n=11,x=5,a=2,b=2)
fit.thaad <- stan(file = "binom.stan",data = data_list_thaad,chains = 2,
                  iter = 5000,warmup = 1000,seed = 12345)
print(fit.thaad)
## Inference for Stan model: binom.
## 2 chains, each with iter=5000; warmup=1000; thin=1; 
## post-warmup draws per chain=4000, total post-warmup draws=8000.
## 
##        mean se_mean   sd   2.5%    25%    50%    75%  97.5% n_eff Rhat
## p      0.47    0.00 0.12   0.25   0.39   0.47   0.55   0.70  2762    1
## pp     5.50    0.03 2.57   1.00   4.00   5.00   7.00  10.00  7978    1
## lp__ -12.26    0.01 0.69 -14.23 -12.43 -11.99 -11.81 -11.75  2953    1
## 
## Samples were drawn using NUTS(diag_e) at Thu Mar 28 13:12:15 2019.
## For each parameter, n_eff is a crude measure of effective sample size,
## and Rhat is the potential scale reduction factor on split chains (at 
## convergence, Rhat=1).
stan_hist(fit.thaad)

s1.thaad <- extract(fit.thaad)


#PATRIOT PAC-3 N=11,X=10
data_list_pac3 <- list(n=11,x=10,a=2,b=2)
fit.pac3 <- stan(file = "binom.stan",data = data_list_pac3,chains = 2,
                  iter = 5000,warmup = 1000,seed = 12345)
print(fit.pac3)
## Inference for Stan model: binom.
## 2 chains, each with iter=5000; warmup=1000; thin=1; 
## post-warmup draws per chain=4000, total post-warmup draws=8000.
## 
##       mean se_mean   sd   2.5%   25%   50%   75% 97.5% n_eff Rhat
## p     0.77    0.00 0.10   0.55  0.70  0.78  0.84  0.93  2823    1
## pp    5.50    0.03 2.58   1.00  4.00  6.00  7.00 10.00  8000    1
## lp__ -9.79    0.01 0.72 -11.85 -9.97 -9.52 -9.33 -9.28  3068    1
## 
## Samples were drawn using NUTS(diag_e) at Thu Mar 28 13:12:18 2019.
## For each parameter, n_eff is a crude measure of effective sample size,
## and Rhat is the potential scale reduction factor on split chains (at 
## convergence, Rhat=1).
stan_hist(fit.pac3)

s1.pac3 <- extract(fit.pac3)

kn17 <- s1.kn17$p
aegis <- s1.aegis$p
thaad <- s1.thaad$p
pac3 <- s1.pac3$p

4 Reliability of missile defense

4.1 One AEGIS, one THAAD and one PAC-3 missiles

library(ggplot2)
prob_hist <- function(prob,num1,num2,num3){
  hist_label <- "Probability density of KN17 intercept by"
  ggplot(data=as.data.frame(prob), aes(prob))+
    geom_histogram(bins = 30,col="black",fill="green") + 
    geom_vline(xintercept = mean(prob), color = "red") + 
    geom_errorbarh(aes(y=-5, xmin=quantile(prob,0.1),
                       xmax=quantile(prob,0.9)), 
                   data=as.data.frame(prob), col="#0094EA", size=3) +
    ggtitle(paste(hist_label,num1," AEGIS,",num2," THAAD," ,num3," PAC-3",sep=" ")) + labs(x="Probability")
}

bmd_1_1 <- (1-kn17*(1-aegis)*(1-thaad)*(1-pac3))
quantile(bmd_1_1,c(0.1,0.5,0.9))
##       10%       50%       90% 
## 0.9742350 0.9881510 0.9952235
prob_hist(bmd_1_1,"1","1","1")

4.2 Two AEGIS, one THAAD and one PAC-3 missiles

bmd_2_1 <- (1-kn17*(1-aegis)^2*(1-thaad)*(1-pac3))
quantile(bmd_2_1,c(0.1,0.5,0.9))
##       10%       50%       90% 
## 0.9934273 0.9974410 0.9991137
prob_hist(bmd_2_1,"2","1","1")

4.3 Two AEGIS, two THAAD and two PAC-3 missiles

bmd_2_2 <- (1-kn17*(1-aegis)^2*(1-thaad)^2*(1-pac3)^2)
quantile(bmd_2_2,c(0.1,0.5,0.9))
##       10%       50%       90% 
## 0.9988094 0.9997078 0.9999455
prob_hist(bmd_2_2,"2","2","2")

4.4 Four AEGIS, two THAAD and two PAC-3 missiles

bmd_4_2 <- (1-kn17*(1-aegis)^4*(1-thaad)^2*(1-pac3)^2)
quantile(bmd_4_2,c(0.1,0.5,0.9))
##       10%       50%       90% 
## 0.9999209 0.9999865 0.9999982
prob_hist(bmd_4_2,"4","2","2")

5 Conclusion

  1. Probability for the KN17 intercept by single AEGIS, single THAAD and single PAC-3 missiles provided KN17 would have success launch event can be estimated as 95% credible interval \(0.974\le P_{1,1,1}\le0.995\) with the mean \(M[P_{1,1,1}]=0.988\).
  2. Probability for the KN17 intercept by two AEGIS, single THAAD and single PAC-3 missiles provided KN17 would have success launch event can be estimated as 95% credible interval \(0.993\le P_{2,1,1}\le0.999\) with the mean \(M[P_{2,1,1}]=0.997\).
  3. Probability for the KN17 intercept by two AEGIS, two THAAD and two PAC-3 missiles provided KN17 would have success launch event can be estimated as 95% credible interval \(0.9988\le P_{2,2,2}\le0.9999\) with the mean \(M[P_{2,2,2}]=0.9997\).
  4. Probability for the KN17 intercept by four AEGIS, two THAAD and two PAC-3 missiles provided KN17 would have success launch event can be estimated as 95% credible interval \(0.99992\le P_{4,2,2}\le0.99999\) with the mean \(M[P_{4,2,2}]=0.99998\).
  5. All the estimates made above are based on the assumption that KN17, AEGIS, THAAD and PAC-3 flight test data are correct in terms of \(Success\) and \(Failure\) events.