High quality spectrogram with a few seconds signal

I am trying to get a high quality spectrogram with a signal that is only 5 seconds long. This is the line I am using: the sampling frequency is 1000Hz.

spectrogram(signal,128,64,2048,fs,'yaxis')

I do not get the quality I need. Is there something I could do?

Answer 1

[Rick Rosson]

Please try the following:

   % Window duration (in seconds):
   dur = 0.5;

   % Spectrogram settings (in samples):
   winSize = round(fs*dur);
   overlap = round(winSize/2);
   fftSize = winSize;

   % Plot the spectrogram:
   spectrogram(signal,winSize,overlap,fftSize,fs,'yaxis');

Then try experimenting with the value of dur until the spectrogram provides a good balance between time resolution and frequency resolution.

[Diana]

Hello Rick,

Thank you for your answer, I tried it, but I still don't get the results I need.

Diana

[Rick Rosson]

What values did you try for dur? What are you trying to do?