Demonstrate the solar sail disturbance model in Earth orbit.

The orbit is a circular equatorial orbit at 8000 km around the Earth. The sail is always sun-pointing. This demo is the same as the built-in demo in SailDisturbance.

Functions demonstrated:
   QSunPointing
   SailDisturbance

Since version 7.
------------------------------------------------------------------------
See also DrawSCPlanPlugIn, Constant, JD2000, JD2T, Period, PltOrbit,
Planets, QSunPointing, SolarSys, SunV1, DisturbanceStruct,
EnvironmentStruct, ProfileStruct, SailDisturbance, SailEnvironment
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Contents

%-------------------------------------------------------------------------------
%	Copyright (c) 2005 Princeton Satellite Systems, Inc.
%   All rights reserved.
%-------------------------------------------------------------------------------

clear SailDisturbance

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

Load the sail model

%--------------------
g = load('SailWithBoom.mat');
DrawSCPlanPlugIn('initialize',g);

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

Create the profile

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

Parameters for the orbit. We are creating a circular orbit.

%------------------------------------------------------------
a          = linspace(0,2*pi);
r          = 8000; % Radius in km
n          = length(a);
mu         = Constant('mu earth');

Default profile data structure

%-------------------------------
p          = ProfileStruct;

Range of Julian dates

%----------------------
p.jD       = linspace(0,Period(r))/86400 + JD2000;

Orbit vector

%-------------
p.r        = r*[cos(a);sin(a);zeros(1,n)];
PltOrbit( [r 0 0 0 0 0], p.jD(1) );
hold on;
plot3(p.r(1,1),p.r(2,1),p.r(3,1),'b*')

Velocity vector

%----------------
p.v        = sqrt(mu/r)*[sin(a);cos(a);zeros(1,n)];

Quaternion (always sun pointing)

%----------------------------------
p.q        = QSunPointing( SunV1( p.jD, p.r ) );

% Gimbal angles. The sail is two body with a gimbaled boom
% The first angle is the one nearest the core
% The axes correspond to the angles
% The body array says each gimbal is at the joint between the

core and the boom. The core is defined as body 1 in the CAD file

%-----------------------------------------------------------------
p.angle    = zeros(2,n);
p.axis     = [1 0;0 1;0 0];
p.body     = [2 2];

Earth orbit around the sun

%---------------------------
[planet, aP, eP, iP, WP, wP, LP, jDRefP] = Planets( 'rad', 'Earth' );
[rX0, rY0, rZ0] = SolarSys( iP, WP, wP, aP, eP, LP, planet, jDRefP, JD2T( p.jD  ) );
p.rPlanetH = Constant('au')*[rX0;rY0;rZ0];

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

Create the data structure

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

Get default structure for disturbances and environment

%-------------------------------------------------------
d          = DisturbanceStruct;
d          = EnvironmentStruct( d );

Turn on aerodynamics

%---------------------
d.aeroOn   = 1.0;

Turn on Earth albedo

%----------------------
d.albedoOn = 1.0;

Turn on solar

%--------------
d.solarOn  = 1.0;

Turn on magnetic torques

%-------------------------
d.magOn    = 1.0;

Turn on earth radiation

%------------------------
d.radOn    = 1.0;

Turn on gravity gradient

%-------------------------
d.ggOn     = 1.0;

% Orbiting the earth. SailDisturbance can handle any planet or
% a heliocentric orbit. However, not all planets have magnetic

field models or atmospheric density models.

%-------------------------------------------------------------
d.planet   = 'Earth';

Use the dipole magnetic field model

%------------------------------------
d.magModel = 'BDipole';

Use the exponential atmospheric density model

%----------------------------------------------
d.atmModel = 'AtmDens2';

% Compute the disturbances. It will automatically plot the results.
% The inputs are ( cad model, profile structure, environment, function

control structure )

%----------------------------------------------------------------------------
e = SailEnvironment( d.planet, p, d );
SailDisturbance( g, p, e, d );


%--------------------------------------
% PSS internal file version information
%--------------------------------------

Published with MATLAB® R2020a