Integration Accuracy for PropagateOrbitPlugin.

Propagate a circular 7000 km orbit and look at various combinations of tolerance and relative tolerance. Loads OrbitIntegrationAccuracy.mat ------------------------------------------------------------------------ See also NewFig, Mag, PropagateOrbitPlugIn ------------------------------------------------------------------------

Contents

%-------------------------------------------------------------------------------
%   Copyright (c) 2000 Princeton Satellite Systems, Inc. All rights reserved.
%-------------------------------------------------------------------------------

d          = load('OrbitIntegrationAccuracy.mat');
tag        = PropagateOrbitPlugIn( 'initialize' );

d.relTol   = 1.e-12;
d.tol      = 1.e-12;
PropagateOrbitPlugIn( 'set data', tag, d );
tic
PropagateOrbitPlugIn( 'propagate', tag );
time1212 = toc;
r          = PropagateOrbitPlugIn( 'get r', tag );
if( isempty(r) )
  return;
end

error1212  = Mag(r) - 7000;
PropagateOrbitPlugIn( 'close plots', tag  );

d.relTol   = 1.e-6;
PropagateOrbitPlugIn( 'set data', tag, d );
tic
PropagateOrbitPlugIn( 'propagate', tag );
time0612 = toc;
r          = PropagateOrbitPlugIn( 'get r', tag );
if( isempty(r) )
  return;
end

error0612  = Mag(r) - 7000;
PropagateOrbitPlugIn( 'close plots', tag  );

d.tol      = 1.e-6;
PropagateOrbitPlugIn( 'set data', tag, d );
tic
PropagateOrbitPlugIn( 'propagate', tag );
time0606 = toc;
r          = PropagateOrbitPlugIn( 'get r', tag );
if( isempty(r) )
  return;
end

error0606  = Mag(r) - 7000;
PropagateOrbitPlugIn( 'close plots', tag  );

d.relTol   = 1.e-12;
PropagateOrbitPlugIn( 'set data', tag, d );
tic
PropagateOrbitPlugIn( 'propagate', tag );
time1206 = toc;
r          = PropagateOrbitPlugIn( 'get r', tag );
if( isempty(r) )
  return;
end

error1206  = Mag(r) - 7000;
PropagateOrbitPlugIn( 'close plots', tag  );

Generate the plots

%-------------------
t          = 0:(d.nSamp-1);

fprintf('Time for Rel Tol = %6.0e Abs Tol = %6.0e is %12.4e\n',1e-12,1e-12,time1212)
fprintf('Time for Rel Tol = %6.0e Abs Tol = %6.0e is %12.4e\n',1e-6, 1e-12,time0612)
fprintf('Time for Rel Tol = %6.0e Abs Tol = %6.0e is %12.4e\n',1e-6, 1e-6, time0606)
fprintf('Time for Rel Tol = %6.0e Abs Tol = %6.0e is %12.4e\n',1e-12,1e-6, time1206)

NewFig('Orbit Integration Accuracy')

subplot(2,2,1)
plot( t(1:length(error1212)), error1212*1e5 )
xlabel('Time (hr)')
ylabel('Error (cm)');
grid
title(sprintf('Rel Tol = %6.0e Abs Tol = %6.0e',1e-12,1e-12));

subplot(2,2,2)
plot( t(1:length(error0612)), error0612*1e3)
xlabel('Time (hr)')
ylabel('Error (m)');
grid
title(sprintf('Rel Tol = %6.0e Abs Tol = %6.0e',1e-6,1e-12));

subplot(2,2,3)
plot( t(1:length(error0606)), error0606*1e3 )
xlabel('Time (hr)')
ylabel('Error (m)');
grid
title(sprintf('Rel Tol = %6.0e Abs Tol = %6.0e',1e-6,1e-6));

subplot(2,2,4)
plot( t(1:length(error1206)), error1206*1e5 )
xlabel('Time (hr)')
ylabel('Error (cm)');
grid
title(sprintf('Rel Tol = %6.0e Abs Tol = %6.0e',1e-12,1e-6));

Time for Rel Tol =  1e-12 Abs Tol =  1e-12 is   3.8459e+00
Time for Rel Tol =  1e-06 Abs Tol =  1e-12 is   2.8154e+00
Time for Rel Tol =  1e-06 Abs Tol =  1e-06 is   2.8272e+01
Time for Rel Tol =  1e-12 Abs Tol =  1e-06 is   2.9769e+00

Test for different sample intervals

%------------------------------------
d.relTol   = 1.e-12;
d.tol      = 1.e-12;
d.nSamp    = 40;
d.t        = linspace(0,d.duration,d.nSamp);
PropagateOrbitPlugIn( 'set data', tag, d );
tic
PropagateOrbitPlugIn( 'propagate', tag );
time40 = toc;
PropagateOrbitPlugIn( 'close plots', tag  );

d.nSamp    = 20;
d.t        = linspace(0,d.duration,d.nSamp);
PropagateOrbitPlugIn( 'set data', tag, d );
tic
PropagateOrbitPlugIn( 'propagate', tag );
time20 = toc;
PropagateOrbitPlugIn( 'close plots', tag  );


fprintf('Time for 81 samples %12.4e\n',time1212)
fprintf('Time for 40 samples %12.4e\n',time40  )
fprintf('Time for 20 samples %12.4e\n',time20  )


%--------------------------------------

Time for 81 samples   3.8459e+00
Time for 40 samples   3.4690e+00
Time for 20 samples   4.3696e+00

Published with MATLAB® R2021a