MATLAB Listing

%Figures 2.13; ‘Mobile satellite communication; Principles and trends’ by M.Richharia;

%Semimajor axis versus rate of precession of ascending node (deg/day);

%Equation (2.14) of ‘Satellite Communication Systems:Design Principles’ by M.Richharia;

%Matlab source code written by AR/MR:Year 2000;

%Graph view changed as required

R=6378; %Mean equatorial radius;

a=linspace(6378+500,15000+6378,1000);%semi major axis;

figure(‘color’,’white’);

hold;

i = 45;% equatorial axis;

e = 0.1; % eccentricity;

wdota=9.95*(R./a).^3.5*(cos (i*pi/180))/(1-e^2)^2;     

i = 90;% equatorial axis;

e = 0.1; % eccentricity;

wdotb=9.95*(R./a).^3.5*(cos (i*pi/180))/(1-e^2)^2;

i = 5;% equatorial axis;

e = 0.1; % eccentricity;

wdotc=9.95*(R./a).^3.5*(cos (i*pi/180))/(1-e^2)^2;      

i = 63.4;% equatorial axis;

e = 0.1; % eccentricity;

wdotd=9.95*(R./a).^3.5*(cos (i*pi/180))/(1-e^2)^2;

%Plot figure;

plot(a,wdota,’k’,a,wdotb,’k’,a,wdotc,’k’,a,wdotd,’k’)

%legend(‘i=45′,’i=90′,’i=5′,’i=63.4’);

axis([700+6378 15000+6378 -inf inf]);

xlabel(‘Semi-major axis (Km)’);

ylabel(‘Rate of precession of ascending node (deg/day)’);

grid on;

zoom;