function [state_eq, obser_eq, Nx, Ny, Nu, NparSys, Nparam, NparID, dt, Ndata, Nzi, izhf, ...
             t, Z, Uinp, param, parFlag, x0, iArtifStab, StabMat] = mDefCase08(test_case)

% Definition of model, flight data, initial values etc. 
% test_case = 8 -- Unstable aircraft, short period, Output error method
% variables:       states  - w, q
%                  outputs - az, w, q
%                  inputs  - de
%
% Inputs
%    test_case    test case number
%
% Outputs
%    state_eq     function to code right hand sides of state equations       
%    obser_eq     function to code right hand sides of observation equations
%    Nx           number of states 
%    Ny           number of observation variables
%    Nu           number of input (control) variables
%    NparSys      number of system parameters
%    Nparam       total number of system and bias parameters
%    NparID       total number of parameters to be estimated (free parameters)
%    dt           sampling time
%    Ndata        total number of data points for Nzi time segments
%    Nzi          number of time segments (maneuvers) to be analyzed simultaneously
%    izhf         cumulative index at which the maneuvers end when concatenated
%    t            time vector
%    Z            observation variables: Data array of measured outputs (Ndata,Ny)
%    Uinp         input variables: Data array of measured input (Ndata,Nu)
%    param        initial starting values for unknown parameters (aerodynamic derivatives) 
%    parFlag      flags for free and fixed parameters
%    x0           initial conditions on state variables
%    iArtifStab   integer flag to invoke artificial stabilization
%                 = 0: No artificial stabilization
%                 > 0: Artificial stabilization (needs definition of StabMat)
%    StabMat      artificial stabilization matrix; (Nx,Ny); nonzero only for iArtifStab>0           
%

% Constants
d2r = pi/180;
r2d = 180/pi;

%----------------------------------------------------------------------------------------
% Model definition
state_eq   = 'xdot_TC08_uAC';          % Function for state equations       
obser_eq   = 'obs_TC08_uAC';           % Function for observation equations
Nx         = 2;                        % Number of states 
Ny         = 3;                        % Number of observation variables
Nu         = 1;                        % Number of input (control) variables
NparSys    = 6;                        % Number of system parameters
Nparam     = NparSys;                  % Total number of system and bias parameters
dt         = 0.05;                     % Sampling time
iArtifStab = 0;                        % No artificial stabilization

disp(['Test Case = ', num2str(test_case)]);
disp('Unstable aircraft, short period: Nx=2, Ny=3, Nu=1')

%----------------------------------------------------------------------------------------
% Load flight data for Nzi time segments to be analyzed and concatenate 
load -ascii ..\flt_data\unStabAC_sim.asc;
Nzi  = 1;
data = unStabAC_sim;     

% Number of data points
Ndata = size(data,1);
izhf  = Ndata;

% Generate new time axis
t = [0:dt:Ndata*dt-dt]';

% Observation variables az, w, q
Z = [data(:,6) data(:,3) data(:,4)];

% Input variables de
Uinp = [data(:,5)];

% Initial starting values for unknown parameters (aerodynamic derivatives) 
param = [-1.22871D+00; -1.47680D+00; -4.20491D+00;... 
          1.16197D-01; -2.70670D+00; -1.87718D+01];

% Flags for free and fixed parameters
parFlag = [1; 0; 1; ...           % Zq fixed
           1; 1; 1 ];

% Total number of free parameters
NparID = size(find(parFlag~=0),1); 

% Initial conditions w0, q0
x0 = [0.0; 0.0];

% Artificial stabilization matrix
StabMat = zeros(Nx,Ny);