hyperpar_ass_prop_coupled.jl

# This scripts stores the hyperpars used in the uncoupled propoal particle filters scenarios
# It also includes the used proposal functions, and parameters used in propoal functions
using Gen

Nx = 32   # number of nodes
Nt = 200  # Assuming Nt is your total number of timesteps
start_ass_time = 100 # warm-up period 



# The model error parameters are tuned for better performance
# These parameters are given in main scripts
# std_atm_sys = 0.1 # assumed model error for atm states
# std_ocea_sys = 0.1 # assumed model error for ocea states

# Initial conditions for Atmos and Ocean
# It incluedes all initial values for Nx grids
# These parameters are same as synthetic_truth generation parameters
mu_atm_ini = 0.0
mu_ocea_ini = 0.0
std_atm_ini = 1.0
std_ocea_ini = 1.0
std_atm_obs = 0.3
std_ocea_obs = 0.3

time_window = 1
std_proposal_atm = 0.005   # This the random error added during resampling for atm states
std_proposal_ocea = 0.005  # This the random error added during resampling for ocean states




import Distributions

# This function is used as proposal function to rejunavate particles before the second updating setp.
# I set this function separately because we have a warm-up period in the data assimilation experiment settings.
# Proposal_atm is used in estimating atm states to generate ocean particles
# @gen function proposal_function_ini(prev_trace, T)
#     for i in 1:1:Nx
#         {(:initial_v => i => :ocea_ini)} ~ normal(prev_trace[(:initial_v=>i=>:ocea_ini)], abs(std_proposal_atm * prev_trace[(:initial_v=>i=>:ocea_ini)]))
#         {(:initial_u => i => :atm_ini)} ~ normal(prev_trace[(:initial_u=>i=>:atm_ini)], abs(std_proposal_ocea * prev_trace[(:initial_u=>i=>:atm_ini)]))
#         for tt in 1:T-1
#             {(:chain => tt => :v => i => :v)} ~ normal(prev_trace[(:chain=>tt=>:v=>i=>:v)], abs(std_proposal_atm * prev_trace[(:chain=>tt=>:v=>i=>:v)]))
#             {(:chain => tt => :u => i => :u)} ~ normal(prev_trace[(:chain=>tt=>:u=>i=>:u)], abs(std_proposal_ocea * prev_trace[(:chain=>tt=>:u=>i=>:u)]))
#         end
#     end
# end


@gen function proposal_function(prev_trace, T)
    for i in 1:1:Nx
        for tt in T:1:T
            {(:chain => tt => :v => i => :v)} ~ normal(prev_trace[(:chain=>tt=>:v=>i=>:v)], abs(std_proposal_atm * prev_trace[(:chain=>tt=>:v=>i=>:v)]))
            {(:chain => tt => :u => i => :u)} ~ normal(prev_trace[(:chain=>tt=>:u=>i=>:u)], abs(std_proposal_ocea * prev_trace[(:chain=>tt=>:u=>i=>:u)]))
        end
    end
end