File:Chirp animation.gif
No higher resolution available.
Chirp_animation.gif (640 × 479 pixels, file size: 234 KB, MIME type: image/gif, looped, 11 frames, 5.5 s)
 | This is a file from the Wikimedia Commons. Information from its description page there is shown below. Commons is a freely licensed media file repository. You can help. |
Summary
| Description | Chirp and impulse signals and their (selected) [[w:spectral component|]]s. On the bottom given four [[w:monochromatic|]] components, sine waves of different frequency. The red line in the waves give the relative [[w:phase shift|]] to the other sine waves, originating from the chirp characteristic. The animation removes the phase shift step by step (like with [[w:matched filter|]]ing), resulting in a sinc pulse when no relative phase shift is left. |
| Date | |
| Source | Own work |
| Author | Andrew0090 |
Licensing
I, the copyright holder of this work, hereby publish it under the following license:
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
Source code (Octave)
% Generate a chirp signal animation
% To combine frames into an animated .gif file use:
% convert -delay 50 output/*.png chirp_animation.gif
N=513;
freqs=200;
t = linspace (-0.5, 0.5, N);
n=0;
lw = 2;
fs = 10;
fw = 'bold';
for dispersion = linspace (-0.001, 0.001, 11)
sig = zeros (freqs, N);
for f = 1:freqs
sig(f,:) = cos (f * pi * (t - dispersion * f));
end
subplot (2, 1, 1);
plot (t, sum (sig, 1), 'r', 'linewidth', lw);
axis([-0.5, 0.5, -100, 200]);
set(gca, 'fontsize', fs);
set(gca, 'FontWeight', fw);
set(gca, 'linewidth', lw)
set(gca, 'XTick', linspace (-0.5, 0.5, 5));
grid;
subplot (2, 1, 2);
hold off;
plot (t, sig(1,:), 'linewidth', lw);
hold on;
plot (t, sig(4,:) + 3, 'linewidth', lw);
plot (t, sig(16,:) + 6, 'linewidth', lw);
plot (t, sig(64,:) + 9, 'linewidth', lw);
plot ([1,1]*dispersion*1, [-1.2,1.2], 'r', 'linewidth', 6);
plot ([1,1]*dispersion*4, [1.8,4.2], 'r', 'linewidth', 6);
plot ([1,1]*dispersion*16, [4.8,7.2], 'r', 'linewidth', 6);
plot ([1,1]*dispersion*64, [7.8,10.2], 'r', 'linewidth', 6);
axis([-0.5, 0.5, -1.5, 10.5], 'labelx', 'tickx');
set(gca, 'fontsize', fs);
set(gca, 'FontWeight', fw);
set(gca, 'linewidth', lw)
set(gca, 'XTick', linspace (-0.5, 0.5, 5));
grid;
pause(0.5);
n = n+1;
filename=sprintf('output/%05d.png',n);
print(filename, '-S640,480');
end
|
The categories of this image need checking. You can do so here.
|
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 21:52, 5 December 2013 | | 640 × 479 (234 KB) | wikimediacommons>Andrew0090 | Color and thickness of phase markers. |
File usage
The following page uses this file:
