Some Orbital Mechanics Matlab Codes. Heavily based on the "Orbital Mechanics for Engineers, Howard D. Curtis" book.

You can initialize an Orbit in these ways depending on the available input/initial conditions:

• $R_0$ and $V_0$
• Orbital Elements
• Two Line Elements (TLE)
• Orbit Determination
  • GIBBS

You must choose the method used to solve for future epochs from:

• Kepler Equation
• Cowell Method

You can specify the time-span of the calculation using the dt arguement

• An Orbit with Orbital Elements of the starting state and Kepler Equation as the solving method:

orb1 = Orbit('OE','f(t)',r_p = 6700,r_a = 10000,...
    theta_0 = 230*pi/180, Omega_0 = 270*pi/180,i = 60*pi/180,...
    omega_0 = 45*pi/180, dt = 5.1610e5);

• An Orbit with $R_0$ and $V_0$ of the starting state and Cowell Method as the solving method with Atmospheric Drag effect :

orb2 = Orbit('RV','Cowell',drag = true,R_0 = [-3670,-3870,4400],V_0 = [4.7,-7.4,1], dt = 5.1610e5);

• An Orbit with Two Line Elements (TLE) of the starting state and Kepler Equation as the solving method:

orb3 = Orbit('TLE','f(t)',drag = false,tle='ISS.txt', dt =  5.1610e5);

• An Orbit with GIBBS method used to determine the starting state and Kepler Equation as the solving method:

orb4 = Orbit('GIBBS','f(t)',R1 = [-294.32,4265.1,4265.1],...
    R2 = [ -1365.5,3637.6,6346.8],R3 = [-2940.3,2473.7, 6555.8], dt = 5.1610e4);

To solve the orbit problem call the solveOrbit() method

orb3 = orb3.solveOrbit();

To plot the Ground Tracks use the plot() method

For 3D tracks use plot3() method

For plotting Ground Tracks:

orb3.plot();

For plotting 3D tracks:

orb3.plot3();

This code takes in consideration J2 perturbation with optional terms being :

• Atmospheric Drag

• Clean the class code
• Improve Orbit Transfer code, use the method in chapter 6, and write its Documentation

• Working code foundation (tested on the textbook's examples).