% plot the impulse response of the Chandler wobble

clear all
close all

% so called quality factor
Qc=179;

% characteristic period in days
Tc=433;

% characteristic frequency
wc=pi*(2+i/Qc)/Tc;

% let time vector run from 0 to twice Tc sampled daily
samprate=1;
t=0:1:100*Tc;
phi = -i*wc*exp(i*wc*t);

figure
subplot(2,1,1)
plot(t,real(phi))
ylabel('Re(phi(t)) (radians/day)')
title('Chandler wobble time-domain impulse response')
subplot(2,1,2)
plot(t,imag(phi))
ylabel('Im(phi(t)) (radians/day)')
xlabel('time (days)')

figure
plot(phi)
ylabel('imag(phi(t))')
xlabel('real(phi(t))')
title('Chandler wobble time domain complex response')
