Demonstrates drag compensation maneuvers.

Loads the file DragCompensationDemo.mat to PropagateOrbitPlugIn. ------------------------------------------------------------------------ See also Constant, Plot2D, TimeLabl, Mag, RV2AE, OrbMnvrSemimajor, PropagateOrbitPlugIn, RV2El, AtmDens2 ------------------------------------------------------------------------

Contents

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

clear el;
mu         = Constant('mu earth');
rE         = Constant('equatorial radius earth');
area       = 1; % m^2
mass       = 100;
cD         = 2.7;
bStar      = cD*area/mass;
H0         = 200;
H1         = 200;
H2         = 180;
rho1       = AtmDens2( 200 );
rho2       = AtmDens2( 180 );
h          = (H2-H1)/log(rho1/rho2);
rho0       = rho1/exp(-H1/h);
dT         = 3600;
nSim       = 10;

t          = (0:(nSim-1))*dT;
xPlot      = zeros(2,length(t));
xPlot(1,:) = h*log( exp(H0/h) - sqrt(mu*rE)*bStar*rho0*1e3*t/h );

Run the orbit propagator in batch

%----------------------------------
d          = load('DragCompensationDemo.mat');
tag        = PropagateOrbitPlugIn( 'initialize' );
PropagateOrbitPlugIn( 'set data', tag, d );
PropagateOrbitPlugIn( 'propagate', tag );

r          = PropagateOrbitPlugIn( 'get r', tag );
v          = PropagateOrbitPlugIn( 'get v', tag );
nP         = size(r,2);

if( ~isempty(r) & ~isempty(v) & nP > 0 )
	t          = t(1:nP);
	xPlot      = xPlot(:,1:nP);

  xPlot(2,:) = RV2AE( r, v, mu ) - rE;
  [t, xLabl] = TimeLabl( t );
  [h, hA]    = Plot2D( t, xPlot, xLabl, 'H' );
  legend( hA.h, 'Analytical', 'Propagator' );

	n = nP;
	for k = 1:n
      el(:,k) = RV2El( r(:,k), v(:,k) )';
	end

	yL = ['a';'i';'W';'w';'e'];
	Plot2D( t, el(1:5,:), 'Time', yL, 'Elements' );

	% Compute the change in semimajor axis
	%--------------------------------------
	deltaA = el(1,1) - el(1,end);

	deltaV = OrbMnvrSemimajor( Mag(v(:,1)),el(1,1),deltaA);

	fprintf('Drag compensation delta-V is %12.4f km/sec\n',deltaV.total);
end


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

Drag compensation delta-V is       0.0093 km/sec

Published with MATLAB® R2021a