Path: CubeSat/MissionPlanning
% Design a repeat ground-track orbit.
Determines the semi-major axis values closest to the desired ratio of
orbits / days. Utilizes the J2 drift to model the satellite orbit rate.
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Usage:
g = RepeatGroundTrack( 'input' );
d = RepeatGroundTrack( g );
d = RepeatGroundTrack( g, 1 ); % generates a plot
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Inputs
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g (.) Data structure with fields
.P0 Desired number of orbits (integer)
.Q0 Desired number of days over which P0 orbits occur
.inc Orbit inclination (rad)
.ecc Orbit eccentricity
.da Range of semi-major axis values to consider (km)
.PMax Maximum number of orbits to consider
.QMax Maximum number of days to consider
doplot (1) Flag to create plot. Default 0.
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Outputs:
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d (.) Data structure with fields
.P Closest number of orbits to meet ratio (integer)
.Q Closest number of days to meet ratio (integer)
.a0 Initial semi major axis guess
.a Closest semi major axis values to meet ratio
.dLon Longitude drift per orbit
.days Number of days per repeat
.anomalisticPeriod Anomalistic period (sec)
.nodalPeriod Nodal period (sec)
doplot (1,1) Plotting flag. Set to 1 to create a plot.
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Reference: Vallado, "Fundamentals of Astrodynamics and Applications",
Second Edition. Sec. 11.4.2, Repeat-Groundtrack orbits.
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Common: Graphics/NewFig
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