Demonstrate sail force plotting functions.

Use a nontrivial heliocentric orbit and random cone and clock angles.

Since version 7.
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See also PlotSailForce2D, PlotSailClock2D, ConeClockToU, Constant,
Plot3D, Unit, El2RV, RVFromKepler, QSail, SailForceSubplots
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Heliocentric orbit
Select random cone and clock angles
Plot the cone angle looking along the sail plane
Plot clock angle
Combination plot

%-------------------------------------------------------------------------------
%  Copyright (c) 2009 Princeton Satellite Systems, Inc.
%-------------------------------------------------------------------------------

Heliocentric orbit

Set an orbit with nontrivial inclination and eccentricity. Elements are [$a$ $i$ $\Omega$ $\omega$ $e$ $M$ ]

el = [Constant('au') 0.2 0 0 0.1 0.3];

% Get the Cartesian position and velocity
[r,v] = El2RV(el);

% The sun vector is just -rHat
s = -Unit(r);

% Create a plot of the entire orbit
Plot3D(RVFromKepler(el))
hold on
plot3(r(1),r(2),r(3),'o')
plot3([0 r(1)],[0 r(2)],[0 r(3)],'b')
sun = plot3(0,0,0,'yo','markersize',15);
set(sun,'color',[1 0.8 0],'MarkerFaceColor',[1 0.8 0])

% Select a reference frame for measuring the angles
qRef = QSail( s, r, v, -1 );

Select random cone and clock angles

Specify a cone angle in the neighborhood of 30 degrees and a clock angle anywhere from 0 to 360 degrees. Use the cone and clock as steering angles for the sail normal. Assume the force vector is "inside" the normal (smaller cone angle) and slightly out-of-plane (slight difference in clock angle).

cone = pi/6 + randn*0.2;
clock = rand*2*pi;
fprintf('Cone angle is %2.2f deg\n',cone*180/pi);
fprintf('Clock angle is %2.2f deg\n',clock*180/pi);
n = -ConeClockToU( cone, clock, qRef );
dClock = 0.05*randn;
disp(dClock*180/pi);
f = ConeClockToU( 0.8*cone, clock+dClock, qRef );

Cone angle is 38.31 deg
Clock angle is 174.74 deg
       2.0476

Plot the cone angle looking along the sail plane

Create a 2D plot of the force, normal, and sun vectors.

PlotSailForce2D( f, n, s )

Plot clock angle

PlotSailClock2D( f, n, [], qRef )

Combination plot

SailForceSubplots( f, n, s, qRef )

This is a demo of the Solar Sail Module for the Spacecraft Control Toolbox. For more information, see our Web site: http://www.psatellite.com/sct