f = xmlread('/home/ivan/Downloads/sentinel1_position.xml');
orbits = f.getElementsByTagName('orbit');

Lo = orbits.getLength;
d = zeros(1, Lo);
d = datetime(d, d, d, d, d, d);
x = zeros(1, Lo);
y = zeros(1, Lo);
z = zeros(1, Lo);
vx = zeros(1, Lo);
vy = zeros(1, Lo);
vz = zeros(1, Lo);

for i = 1:orbits.getLength

  orbit = orbits.item(i-1);
  date = orbit.getElementsByTagName('time').item(0).item(0).getData;
  d(i) = datetime(char(date), 'InputFormat', 'yyyy-MM-dd''T''hh:mm:ss.SSSSSS');
  position = orbit.getElementsByTagName('position').item(0);
  x(i) = str2num(position.getElementsByTagName('x').item(0).item(0).getData);
  y(i) = str2num(position.getElementsByTagName('y').item(0).item(0).getData);
  z(i) = str2num(position.getElementsByTagName('z').item(0).item(0).getData);
  velocity = orbit.getElementsByTagName('velocity').item(0);
  vx(i) = str2num(velocity.getElementsByTagName('x').item(0).item(0).getData);
  vy(i) = str2num(velocity.getElementsByTagName('y').item(0).item(0).getData);
  vz(i) = str2num(velocity.getElementsByTagName('z').item(0).item(0).getData);

end

attitudes = f.getElementsByTagName('attitude');

La = attitudes.getLength;
t = zeros(1, La);
t = datetime(t, t, t, t, t, t);
q0 = zeros(1, La);
q1 = zeros(1, La);
q2 = zeros(1, La);
q3 = zeros(1, La);
wx = zeros(1, La);
wy = zeros(1, La);
wz = zeros(1, La);
roll = zeros(1, La);
pitch = zeros(1, La);
yaw = zeros(1, La);


for i = 1:attitudes.getLength

  attitude = attitudes.item(i-1);
  date = attitude.getElementsByTagName('time').item(0).item(0).getData;
  t(i) = datetime(char(date), 'InputFormat', 'yyyy-MM-dd''T''hh:mm:ss.SSSSSS');
  q0(i) = str2num(attitude.getElementsByTagName('q0').item(0).item(0).getData);
  q1(i) = str2num(attitude.getElementsByTagName('q0').item(0).item(0).getData);
  q2(i) = str2num(attitude.getElementsByTagName('q0').item(0).item(0).getData);
  q3(i) = str2num(attitude.getElementsByTagName('q0').item(0).item(0).getData);
  wx(i) = str2num(attitude.getElementsByTagName('q0').item(0).item(0).getData);
  wy(i) = str2num(attitude.getElementsByTagName('q0').item(0).item(0).getData);
  wz(i) = str2num(attitude.getElementsByTagName('q0').item(0).item(0).getData);
  roll(i) = str2num(attitude.getElementsByTagName('q0').item(0).item(0).getData);
  pitch(i) = str2num(attitude.getElementsByTagName('q0').item(0).item(0).getData);
  yaw(i) = str2num(attitude.getElementsByTagName('q0').item(0).item(0).getData);

end

subplot(2, 3, 1)
plot(d, x, '.-')
grid on
title('x(datetime)')

subplot(2, 3, 2)
plot(d, y, '.-')
grid on
title('y(datetime)')

subplot(2, 3, 3)
plot(d, z, '.-')
grid on
title('z(datetime)')

subplot(2, 3, 4)
plot(d, x, '.-')
grid on
title('Vx(datetime)')

subplot(2, 3, 5)
plot(d, x, '.-')
grid on
title('Vy(datetime)')

subplot(2, 3, 6)
plot(d, x, '.-')
grid on
title('Vz(datetime)')

dnum = datenum(d - d(1));
tnum = datenum(t - t(1));
dstr = datestr(d, 'hh:MM:ss');
tstr = datestr(t, 'hh:MM:ss');