Animate the phasing of Earth and Mars over time.

Uses PlanetPosJPL. Creates a nice animation using PlaybackControls.

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Contents

%--------------------------------------------------------------------------
%   Copyright (c) 2013 Princeton Satellite Systems, Inc.
%   All rights reserved.
%--------------------------------------------------------------------------
%   Since version 2014.1
%--------------------------------------------------------------------------

Initialization

%----------------
jD0         = Date2JD([2004 1 1 0 0 0]);

%au          = Constant('au');
%muSun       = Constant('mu sun');

marsYear	  = 687; % Mars year (days)
days        = 0 : .25 : 2*marsYear;
nT          = length(days);

rE          = zeros(3,nT);
rM          = zeros(3,nT);
vE          = zeros(3,nT);
vM          = zeros(3,nT);

PlanetPosJPL('initialize',[3 4]);

Generate the orbits

%---------------------
for j=1:nT

	jD = jD0 + days(j);

  [r,t,v] = PlanetPosJPL( 'update', jD, 1 );
  rE(:,j) = r(:,1);
  vE(:,j) = v(:,1);
  rM(:,j) = r(:,2);
  vM(:,j) = v(:,2);

end

Plot

%------
NewFig('Earth and Mars Orbits');
set(gcf,'position',[882   686   560   420]);
plot3(rE(1,:),rE(2,:),rE(3,:))
hold on
plot3(rM(1,:),rM(2,:),rM(3,:),'r')
plot3(0,0,0,'y.','markersize',20)
set(gca,'color','k','xcolor','w','ycolor','w','zcolor','w')
set(gcf,'color','k')
axis equal

earth = plot3(rE(1,1),rE(2,1),rE(3,1),'c.','markersize',18);
mars  = plot3(rM(1,1),rM(2,1),rM(3,1),'m.','markersize',18);

cb{1} = @(x) set(earth,'xdata',rE(1,round(x)),'ydata',rE(2,round(x)),'zdata',rE(3,round(x)));
cb{2} = @(x) set(mars, 'xdata',rM(1,round(x)),'ydata',rM(2,round(x)),'zdata',rM(3,round(x)));

PlaybackControls(1,nT,1,cb,1,'Earth / Mars Time Control',[886   561   555   102]);

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Published with MATLAB® R2019a