Two orbits are initialized with a small inclination difference. The orbits

are propagated with Kepler's equations using RVOrbGen. The ECI position
and velocity of each orbit is then transformed into the relative Hills frame.

Since version 7.
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See also Constant, Plot2D, ECI2Hills, RVOrbGen
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%-------------------------------------------------------------------------------
%   Copyright (c) 2002 Princeton Satellite Systems, Inc. All rights reserved.
%-------------------------------------------------------------------------------

clear xH; clear vH; clear rH; clear t;

t          = 0:10:12000;
rE         = Constant('equatorial radius earth');
alt        = 550;
a          = rE + alt;
inc        = 35.4*pi/180;
deltaInc   = .1*pi/180;

el0        = [a, inc, 0, 0, 0, 0];
el1        = [a, inc + deltaInc, 0, 0, 0, 0];

[r0,v0]    = RVOrbGen( el0, t );
[r1,v1]    = RVOrbGen( el1, t );

x0         = [r0; v0];
x1         = [r1; v1];

for i=1:length(t)
   xH(:,i) = ECI2Hills( x0(:,i), x1(:,i) );
end

rH = xH(1:3,:);
vH = xH(4:6,:);

Plot2D( t, rH, 'Time', 'r Hills [km]')
Plot2D( t, vH, 'Time', 'v Hills [km]')



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% PSS internal file version information
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