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Highlights from
The Long-term Evolution of Geosynchronous Transfer Orbits

  • atan3four quadrant inverse tangent
  • ceqm1first order form of Cowell's equations of orbital motion
  • eci2orb1convert eci state vector to six classical orbital
  • eci2orb2convert eci state vector to complete set of classical orbital elements
  • gast1Greenwich apparent sidereal time
  • gdateconvert Julian date to Gregorian (calendar) date
  • geodet1geodetic latitude and altitude
  • getdateinteractive request and input of calendar date
  • getoe(ioev)interactive request of classical orbital elements
  • gettimeinteractive request and input of universal time
  • gravityfirst order equations of orbital motion
  • jd2str(jdate)convert Julian date to string equivalent
  • julianJulian date
  • moonlunar ephemeris
  • oeprint1(mu, oev)print six classical orbital elements
  • om_constantsastrodynamic and utility constants
  • orb2eci(mu, oev)convert classical orbital elements to eci state vector
  • r2rrevolutions to radians function
  • readgm(fname)read gravity model data file
  • readoe1(filename)read orbital elements data file
  • rkf78solve first order system of differential equations
  • sun1solar ephemeris
  • svprint(r, v)print position and velocity vectors and magnitudes
  • gto.m
  • View all files
5.0 | 2 ratings Rate this file 15 Downloads (last 30 days) File Size: 696 KB File ID: #41888 Version: 1.0

The Long-term Evolution of Geosynchronous Transfer Orbits


David Eagle (view profile)


Interactive MATLAB script that predicts the long-term evolution of geosynchronous transfer orbits.

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File Information

This MATLAB script implements a special perturbation solution of orbital motion using a variable step size Runge-Kutta-Fehlberg (RKF78) integration method to numerically solve Cowell’s form of the system of differential equation subject to the central body gravity and other external forces. This is also called the orbital initial value problem (IVP).

The user can choose to model one or more of the following perturbations:

• non-spherical Earth gravity
• point mass solar gravity
• point mass lunar gravity

After the orbit propagation is complete, this script can plot the following classical orbital elements:

• semimajor axis
• eccentricity
• orbital inclination
• argument of perigee
• right ascension of the ascending node
• true anomaly
• geodetic perigee altitude
• geodetic apogee altitude

MATLAB release MATLAB 7.12 (R2011a)
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Comments and Ratings (2)
26 Jul 2015 HENRY XSCC  
10 Jun 2014 sun Chong  

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